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1 | /* |
1 | /* |
2 | This is a version (aka dlmalloc) of malloc/free/realloc written by |
2 | This is a version (aka dlmalloc) of malloc/free/realloc written by |
3 | Doug Lea and released to the public domain, as explained at |
3 | Doug Lea and released to the public domain, as explained at |
4 | http://creativecommons.org/publicdomain/zero/1.0/ Send questions, |
4 | http://creativecommons.org/publicdomain/zero/1.0/ Send questions, |
5 | comments, complaints, performance data, etc to dl@cs.oswego.edu |
5 | comments, complaints, performance data, etc to dl@cs.oswego.edu |
6 | 6 | ||
7 | * Version 2.8.6 Wed Aug 29 06:57:58 2012 Doug Lea |
7 | * Version 2.8.6 Wed Aug 29 06:57:58 2012 Doug Lea |
8 | Note: There may be an updated version of this malloc obtainable at |
8 | Note: There may be an updated version of this malloc obtainable at |
9 | ftp://gee.cs.oswego.edu/pub/misc/malloc.c |
9 | ftp://gee.cs.oswego.edu/pub/misc/malloc.c |
10 | Check before installing! |
10 | Check before installing! |
11 | 11 | ||
12 | * Quickstart |
12 | * Quickstart |
13 | 13 | ||
14 | This library is all in one file to simplify the most common usage: |
14 | This library is all in one file to simplify the most common usage: |
15 | ftp it, compile it (-O3), and link it into another program. All of |
15 | ftp it, compile it (-O3), and link it into another program. All of |
16 | the compile-time options default to reasonable values for use on |
16 | the compile-time options default to reasonable values for use on |
17 | most platforms. You might later want to step through various |
17 | most platforms. You might later want to step through various |
18 | compile-time and dynamic tuning options. |
18 | compile-time and dynamic tuning options. |
19 | 19 | ||
20 | For convenience, an include file for code using this malloc is at: |
20 | For convenience, an include file for code using this malloc is at: |
21 | ftp://gee.cs.oswego.edu/pub/misc/malloc-2.8.6.h |
21 | ftp://gee.cs.oswego.edu/pub/misc/malloc-2.8.6.h |
22 | You don't really need this .h file unless you call functions not |
22 | You don't really need this .h file unless you call functions not |
23 | defined in your system include files. The .h file contains only the |
23 | defined in your system include files. The .h file contains only the |
24 | excerpts from this file needed for using this malloc on ANSI C/C++ |
24 | excerpts from this file needed for using this malloc on ANSI C/C++ |
25 | systems, so long as you haven't changed compile-time options about |
25 | systems, so long as you haven't changed compile-time options about |
26 | naming and tuning parameters. If you do, then you can create your |
26 | naming and tuning parameters. If you do, then you can create your |
27 | own malloc.h that does include all settings by cutting at the point |
27 | own malloc.h that does include all settings by cutting at the point |
28 | indicated below. Note that you may already by default be using a C |
28 | indicated below. Note that you may already by default be using a C |
29 | library containing a malloc that is based on some version of this |
29 | library containing a malloc that is based on some version of this |
30 | malloc (for example in linux). You might still want to use the one |
30 | malloc (for example in linux). You might still want to use the one |
31 | in this file to customize settings or to avoid overheads associated |
31 | in this file to customize settings or to avoid overheads associated |
32 | with library versions. |
32 | with library versions. |
33 | 33 | ||
34 | * Vital statistics: |
34 | * Vital statistics: |
35 | 35 | ||
36 | Supported pointer/size_t representation: 4 or 8 bytes |
36 | Supported pointer/size_t representation: 4 or 8 bytes |
37 | size_t MUST be an unsigned type of the same width as |
37 | size_t MUST be an unsigned type of the same width as |
38 | pointers. (If you are using an ancient system that declares |
38 | pointers. (If you are using an ancient system that declares |
39 | size_t as a signed type, or need it to be a different width |
39 | size_t as a signed type, or need it to be a different width |
40 | than pointers, you can use a previous release of this malloc |
40 | than pointers, you can use a previous release of this malloc |
41 | (e.g. 2.7.2) supporting these.) |
41 | (e.g. 2.7.2) supporting these.) |
42 | 42 | ||
43 | Alignment: 8 bytes (minimum) |
43 | Alignment: 8 bytes (minimum) |
44 | This suffices for nearly all current machines and C compilers. |
44 | This suffices for nearly all current machines and C compilers. |
45 | However, you can define MALLOC_ALIGNMENT to be wider than this |
45 | However, you can define MALLOC_ALIGNMENT to be wider than this |
46 | if necessary (up to 128bytes), at the expense of using more space. |
46 | if necessary (up to 128bytes), at the expense of using more space. |
47 | 47 | ||
48 | Minimum overhead per allocated chunk: 4 or 8 bytes (if 4byte sizes) |
48 | Minimum overhead per allocated chunk: 4 or 8 bytes (if 4byte sizes) |
49 | 8 or 16 bytes (if 8byte sizes) |
49 | 8 or 16 bytes (if 8byte sizes) |
50 | Each malloced chunk has a hidden word of overhead holding size |
50 | Each malloced chunk has a hidden word of overhead holding size |
51 | and status information, and additional cross-check word |
51 | and status information, and additional cross-check word |
52 | if FOOTERS is defined. |
52 | if FOOTERS is defined. |
53 | 53 | ||
54 | Minimum allocated size: 4-byte ptrs: 16 bytes (including overhead) |
54 | Minimum allocated size: 4-byte ptrs: 16 bytes (including overhead) |
55 | 8-byte ptrs: 32 bytes (including overhead) |
55 | 8-byte ptrs: 32 bytes (including overhead) |
56 | 56 | ||
57 | Even a request for zero bytes (i.e., malloc(0)) returns a |
57 | Even a request for zero bytes (i.e., malloc(0)) returns a |
58 | pointer to something of the minimum allocatable size. |
58 | pointer to something of the minimum allocatable size. |
59 | The maximum overhead wastage (i.e., number of extra bytes |
59 | The maximum overhead wastage (i.e., number of extra bytes |
60 | allocated than were requested in malloc) is less than or equal |
60 | allocated than were requested in malloc) is less than or equal |
61 | to the minimum size, except for requests >= mmap_threshold that |
61 | to the minimum size, except for requests >= mmap_threshold that |
62 | are serviced via mmap(), where the worst case wastage is about |
62 | are serviced via mmap(), where the worst case wastage is about |
63 | 32 bytes plus the remainder from a system page (the minimal |
63 | 32 bytes plus the remainder from a system page (the minimal |
64 | mmap unit); typically 4096 or 8192 bytes. |
64 | mmap unit); typically 4096 or 8192 bytes. |
65 | 65 | ||
66 | Security: static-safe; optionally more or less |
66 | Security: static-safe; optionally more or less |
67 | The "security" of malloc refers to the ability of malicious |
67 | The "security" of malloc refers to the ability of malicious |
68 | code to accentuate the effects of errors (for example, freeing |
68 | code to accentuate the effects of errors (for example, freeing |
69 | space that is not currently malloc'ed or overwriting past the |
69 | space that is not currently malloc'ed or overwriting past the |
70 | ends of chunks) in code that calls malloc. This malloc |
70 | ends of chunks) in code that calls malloc. This malloc |
71 | guarantees not to modify any memory locations below the base of |
71 | guarantees not to modify any memory locations below the base of |
72 | heap, i.e., static variables, even in the presence of usage |
72 | heap, i.e., static variables, even in the presence of usage |
73 | errors. The routines additionally detect most improper frees |
73 | errors. The routines additionally detect most improper frees |
74 | and reallocs. All this holds as long as the static bookkeeping |
74 | and reallocs. All this holds as long as the static bookkeeping |
75 | for malloc itself is not corrupted by some other means. This |
75 | for malloc itself is not corrupted by some other means. This |
76 | is only one aspect of security -- these checks do not, and |
76 | is only one aspect of security -- these checks do not, and |
77 | cannot, detect all possible programming errors. |
77 | cannot, detect all possible programming errors. |
78 | 78 | ||
79 | If FOOTERS is defined nonzero, then each allocated chunk |
79 | If FOOTERS is defined nonzero, then each allocated chunk |
80 | carries an additional check word to verify that it was malloced |
80 | carries an additional check word to verify that it was malloced |
81 | from its space. These check words are the same within each |
81 | from its space. These check words are the same within each |
82 | execution of a program using malloc, but differ across |
82 | execution of a program using malloc, but differ across |
83 | executions, so externally crafted fake chunks cannot be |
83 | executions, so externally crafted fake chunks cannot be |
84 | freed. This improves security by rejecting frees/reallocs that |
84 | freed. This improves security by rejecting frees/reallocs that |
85 | could corrupt heap memory, in addition to the checks preventing |
85 | could corrupt heap memory, in addition to the checks preventing |
86 | writes to statics that are always on. This may further improve |
86 | writes to statics that are always on. This may further improve |
87 | security at the expense of time and space overhead. (Note that |
87 | security at the expense of time and space overhead. (Note that |
88 | FOOTERS may also be worth using with MSPACES.) |
88 | FOOTERS may also be worth using with MSPACES.) |
89 | 89 | ||
90 | By default detected errors cause the program to abort (calling |
90 | By default detected errors cause the program to abort (calling |
91 | "abort()"). You can override this to instead proceed past |
91 | "abort()"). You can override this to instead proceed past |
92 | errors by defining PROCEED_ON_ERROR. In this case, a bad free |
92 | errors by defining PROCEED_ON_ERROR. In this case, a bad free |
93 | has no effect, and a malloc that encounters a bad address |
93 | has no effect, and a malloc that encounters a bad address |
94 | caused by user overwrites will ignore the bad address by |
94 | caused by user overwrites will ignore the bad address by |
95 | dropping pointers and indices to all known memory. This may |
95 | dropping pointers and indices to all known memory. This may |
96 | be appropriate for programs that should continue if at all |
96 | be appropriate for programs that should continue if at all |
97 | possible in the face of programming errors, although they may |
97 | possible in the face of programming errors, although they may |
98 | run out of memory because dropped memory is never reclaimed. |
98 | run out of memory because dropped memory is never reclaimed. |
99 | 99 | ||
100 | If you don't like either of these options, you can define |
100 | If you don't like either of these options, you can define |
101 | CORRUPTION_ERROR_ACTION and USAGE_ERROR_ACTION to do anything |
101 | CORRUPTION_ERROR_ACTION and USAGE_ERROR_ACTION to do anything |
102 | else. And if if you are sure that your program using malloc has |
102 | else. And if if you are sure that your program using malloc has |
103 | no errors or vulnerabilities, you can define INSECURE to 1, |
103 | no errors or vulnerabilities, you can define INSECURE to 1, |
104 | which might (or might not) provide a small performance improvement. |
104 | which might (or might not) provide a small performance improvement. |
105 | 105 | ||
106 | It is also possible to limit the maximum total allocatable |
106 | It is also possible to limit the maximum total allocatable |
107 | space, using malloc_set_footprint_limit. This is not |
107 | space, using malloc_set_footprint_limit. This is not |
108 | designed as a security feature in itself (calls to set limits |
108 | designed as a security feature in itself (calls to set limits |
109 | are not screened or privileged), but may be useful as one |
109 | are not screened or privileged), but may be useful as one |
110 | aspect of a secure implementation. |
110 | aspect of a secure implementation. |
111 | 111 | ||
112 | Thread-safety: NOT thread-safe unless USE_LOCKS defined non-zero |
112 | Thread-safety: NOT thread-safe unless USE_LOCKS defined non-zero |
113 | When USE_LOCKS is defined, each public call to malloc, free, |
113 | When USE_LOCKS is defined, each public call to malloc, free, |
114 | etc is surrounded with a lock. By default, this uses a plain |
114 | etc is surrounded with a lock. By default, this uses a plain |
115 | pthread mutex, win32 critical section, or a spin-lock if if |
115 | pthread mutex, win32 critical section, or a spin-lock if if |
116 | available for the platform and not disabled by setting |
116 | available for the platform and not disabled by setting |
117 | USE_SPIN_LOCKS=0. However, if USE_RECURSIVE_LOCKS is defined, |
117 | USE_SPIN_LOCKS=0. However, if USE_RECURSIVE_LOCKS is defined, |
118 | recursive versions are used instead (which are not required for |
118 | recursive versions are used instead (which are not required for |
119 | base functionality but may be needed in layered extensions). |
119 | base functionality but may be needed in layered extensions). |
120 | Using a global lock is not especially fast, and can be a major |
120 | Using a global lock is not especially fast, and can be a major |
121 | bottleneck. It is designed only to provide minimal protection |
121 | bottleneck. It is designed only to provide minimal protection |
122 | in concurrent environments, and to provide a basis for |
122 | in concurrent environments, and to provide a basis for |
123 | extensions. If you are using malloc in a concurrent program, |
123 | extensions. If you are using malloc in a concurrent program, |
124 | consider instead using nedmalloc |
124 | consider instead using nedmalloc |
125 | (http://www.nedprod.com/programs/portable/nedmalloc/) or |
125 | (http://www.nedprod.com/programs/portable/nedmalloc/) or |
126 | ptmalloc (See http://www.malloc.de), which are derived from |
126 | ptmalloc (See http://www.malloc.de), which are derived from |
127 | versions of this malloc. |
127 | versions of this malloc. |
128 | 128 | ||
129 | System requirements: Any combination of MORECORE and/or MMAP/MUNMAP |
129 | System requirements: Any combination of MORECORE and/or MMAP/MUNMAP |
130 | This malloc can use unix sbrk or any emulation (invoked using |
130 | This malloc can use unix sbrk or any emulation (invoked using |
131 | the CALL_MORECORE macro) and/or mmap/munmap or any emulation |
131 | the CALL_MORECORE macro) and/or mmap/munmap or any emulation |
132 | (invoked using CALL_MMAP/CALL_MUNMAP) to get and release system |
132 | (invoked using CALL_MMAP/CALL_MUNMAP) to get and release system |
133 | memory. On most unix systems, it tends to work best if both |
133 | memory. On most unix systems, it tends to work best if both |
134 | MORECORE and MMAP are enabled. On Win32, it uses emulations |
134 | MORECORE and MMAP are enabled. On Win32, it uses emulations |
135 | based on VirtualAlloc. It also uses common C library functions |
135 | based on VirtualAlloc. It also uses common C library functions |
136 | like memset. |
136 | like memset. |
137 | 137 | ||
138 | Compliance: I believe it is compliant with the Single Unix Specification |
138 | Compliance: I believe it is compliant with the Single Unix Specification |
139 | (See http://www.unix.org). Also SVID/XPG, ANSI C, and probably |
139 | (See http://www.unix.org). Also SVID/XPG, ANSI C, and probably |
140 | others as well. |
140 | others as well. |
141 | 141 | ||
142 | * Overview of algorithms |
142 | * Overview of algorithms |
143 | 143 | ||
144 | This is not the fastest, most space-conserving, most portable, or |
144 | This is not the fastest, most space-conserving, most portable, or |
145 | most tunable malloc ever written. However it is among the fastest |
145 | most tunable malloc ever written. However it is among the fastest |
146 | while also being among the most space-conserving, portable and |
146 | while also being among the most space-conserving, portable and |
147 | tunable. Consistent balance across these factors results in a good |
147 | tunable. Consistent balance across these factors results in a good |
148 | general-purpose allocator for malloc-intensive programs. |
148 | general-purpose allocator for malloc-intensive programs. |
149 | 149 | ||
150 | In most ways, this malloc is a best-fit allocator. Generally, it |
150 | In most ways, this malloc is a best-fit allocator. Generally, it |
151 | chooses the best-fitting existing chunk for a request, with ties |
151 | chooses the best-fitting existing chunk for a request, with ties |
152 | broken in approximately least-recently-used order. (This strategy |
152 | broken in approximately least-recently-used order. (This strategy |
153 | normally maintains low fragmentation.) However, for requests less |
153 | normally maintains low fragmentation.) However, for requests less |
154 | than 256bytes, it deviates from best-fit when there is not an |
154 | than 256bytes, it deviates from best-fit when there is not an |
155 | exactly fitting available chunk by preferring to use space adjacent |
155 | exactly fitting available chunk by preferring to use space adjacent |
156 | to that used for the previous small request, as well as by breaking |
156 | to that used for the previous small request, as well as by breaking |
157 | ties in approximately most-recently-used order. (These enhance |
157 | ties in approximately most-recently-used order. (These enhance |
158 | locality of series of small allocations.) And for very large requests |
158 | locality of series of small allocations.) And for very large requests |
159 | (>= 256Kb by default), it relies on system memory mapping |
159 | (>= 256Kb by default), it relies on system memory mapping |
160 | facilities, if supported. (This helps avoid carrying around and |
160 | facilities, if supported. (This helps avoid carrying around and |
161 | possibly fragmenting memory used only for large chunks.) |
161 | possibly fragmenting memory used only for large chunks.) |
162 | 162 | ||
163 | All operations (except malloc_stats and mallinfo) have execution |
163 | All operations (except malloc_stats and mallinfo) have execution |
164 | times that are bounded by a constant factor of the number of bits in |
164 | times that are bounded by a constant factor of the number of bits in |
165 | a size_t, not counting any clearing in calloc or copying in realloc, |
165 | a size_t, not counting any clearing in calloc or copying in realloc, |
166 | or actions surrounding MORECORE and MMAP that have times |
166 | or actions surrounding MORECORE and MMAP that have times |
167 | proportional to the number of non-contiguous regions returned by |
167 | proportional to the number of non-contiguous regions returned by |
168 | system allocation routines, which is often just 1. In real-time |
168 | system allocation routines, which is often just 1. In real-time |
169 | applications, you can optionally suppress segment traversals using |
169 | applications, you can optionally suppress segment traversals using |
170 | NO_SEGMENT_TRAVERSAL, which assures bounded execution even when |
170 | NO_SEGMENT_TRAVERSAL, which assures bounded execution even when |
171 | system allocators return non-contiguous spaces, at the typical |
171 | system allocators return non-contiguous spaces, at the typical |
172 | expense of carrying around more memory and increased fragmentation. |
172 | expense of carrying around more memory and increased fragmentation. |
173 | 173 | ||
174 | The implementation is not very modular and seriously overuses |
174 | The implementation is not very modular and seriously overuses |
175 | macros. Perhaps someday all C compilers will do as good a job |
175 | macros. Perhaps someday all C compilers will do as good a job |
176 | inlining modular code as can now be done by brute-force expansion, |
176 | inlining modular code as can now be done by brute-force expansion, |
177 | but now, enough of them seem not to. |
177 | but now, enough of them seem not to. |
178 | 178 | ||
179 | Some compilers issue a lot of warnings about code that is |
179 | Some compilers issue a lot of warnings about code that is |
180 | dead/unreachable only on some platforms, and also about intentional |
180 | dead/unreachable only on some platforms, and also about intentional |
181 | uses of negation on unsigned types. All known cases of each can be |
181 | uses of negation on unsigned types. All known cases of each can be |
182 | ignored. |
182 | ignored. |
183 | 183 | ||
184 | For a longer but out of date high-level description, see |
184 | For a longer but out of date high-level description, see |
185 | http://gee.cs.oswego.edu/dl/html/malloc.html |
185 | http://gee.cs.oswego.edu/dl/html/malloc.html |
186 | 186 | ||
187 | * MSPACES |
187 | * MSPACES |
188 | If MSPACES is defined, then in addition to malloc, free, etc., |
188 | If MSPACES is defined, then in addition to malloc, free, etc., |
189 | this file also defines mspace_malloc, mspace_free, etc. These |
189 | this file also defines mspace_malloc, mspace_free, etc. These |
190 | are versions of malloc routines that take an "mspace" argument |
190 | are versions of malloc routines that take an "mspace" argument |
191 | obtained using create_mspace, to control all internal bookkeeping. |
191 | obtained using create_mspace, to control all internal bookkeeping. |
192 | If ONLY_MSPACES is defined, only these versions are compiled. |
192 | If ONLY_MSPACES is defined, only these versions are compiled. |
193 | So if you would like to use this allocator for only some allocations, |
193 | So if you would like to use this allocator for only some allocations, |
194 | and your system malloc for others, you can compile with |
194 | and your system malloc for others, you can compile with |
195 | ONLY_MSPACES and then do something like... |
195 | ONLY_MSPACES and then do something like... |
196 | static mspace mymspace = create_mspace(0,0); // for example |
196 | static mspace mymspace = create_mspace(0,0); // for example |
197 | #define mymalloc(bytes) mspace_malloc(mymspace, bytes) |
197 | #define mymalloc(bytes) mspace_malloc(mymspace, bytes) |
198 | 198 | ||
199 | (Note: If you only need one instance of an mspace, you can instead |
199 | (Note: If you only need one instance of an mspace, you can instead |
200 | use "USE_DL_PREFIX" to relabel the global malloc.) |
200 | use "USE_DL_PREFIX" to relabel the global malloc.) |
201 | 201 | ||
202 | You can similarly create thread-local allocators by storing |
202 | You can similarly create thread-local allocators by storing |
203 | mspaces as thread-locals. For example: |
203 | mspaces as thread-locals. For example: |
204 | static __thread mspace tlms = 0; |
204 | static __thread mspace tlms = 0; |
205 | void* tlmalloc(size_t bytes) { |
205 | void* tlmalloc(size_t bytes) { |
206 | if (tlms == 0) tlms = create_mspace(0, 0); |
206 | if (tlms == 0) tlms = create_mspace(0, 0); |
207 | return mspace_malloc(tlms, bytes); |
207 | return mspace_malloc(tlms, bytes); |
208 | } |
208 | } |
209 | void tlfree(void* mem) { mspace_free(tlms, mem); } |
209 | void tlfree(void* mem) { mspace_free(tlms, mem); } |
210 | 210 | ||
211 | Unless FOOTERS is defined, each mspace is completely independent. |
211 | Unless FOOTERS is defined, each mspace is completely independent. |
212 | You cannot allocate from one and free to another (although |
212 | You cannot allocate from one and free to another (although |
213 | conformance is only weakly checked, so usage errors are not always |
213 | conformance is only weakly checked, so usage errors are not always |
214 | caught). If FOOTERS is defined, then each chunk carries around a tag |
214 | caught). If FOOTERS is defined, then each chunk carries around a tag |
215 | indicating its originating mspace, and frees are directed to their |
215 | indicating its originating mspace, and frees are directed to their |
216 | originating spaces. Normally, this requires use of locks. |
216 | originating spaces. Normally, this requires use of locks. |
217 | 217 | ||
218 | ------------------------- Compile-time options --------------------------- |
218 | ------------------------- Compile-time options --------------------------- |
219 | 219 | ||
220 | Be careful in setting #define values for numerical constants of type |
220 | Be careful in setting #define values for numerical constants of type |
221 | size_t. On some systems, literal values are not automatically extended |
221 | size_t. On some systems, literal values are not automatically extended |
222 | to size_t precision unless they are explicitly casted. You can also |
222 | to size_t precision unless they are explicitly casted. You can also |
223 | use the symbolic values MAX_SIZE_T, SIZE_T_ONE, etc below. |
223 | use the symbolic values MAX_SIZE_T, SIZE_T_ONE, etc below. |
224 | 224 | ||
225 | WIN32 default: defined if _WIN32 defined |
225 | WIN32 default: defined if _WIN32 defined |
226 | Defining WIN32 sets up defaults for MS environment and compilers. |
226 | Defining WIN32 sets up defaults for MS environment and compilers. |
227 | Otherwise defaults are for unix. Beware that there seem to be some |
227 | Otherwise defaults are for unix. Beware that there seem to be some |
228 | cases where this malloc might not be a pure drop-in replacement for |
228 | cases where this malloc might not be a pure drop-in replacement for |
229 | Win32 malloc: Random-looking failures from Win32 GDI API's (eg; |
229 | Win32 malloc: Random-looking failures from Win32 GDI API's (eg; |
230 | SetDIBits()) may be due to bugs in some video driver implementations |
230 | SetDIBits()) may be due to bugs in some video driver implementations |
231 | when pixel buffers are malloc()ed, and the region spans more than |
231 | when pixel buffers are malloc()ed, and the region spans more than |
232 | one VirtualAlloc()ed region. Because dlmalloc uses a small (64Kb) |
232 | one VirtualAlloc()ed region. Because dlmalloc uses a small (64Kb) |
233 | default granularity, pixel buffers may straddle virtual allocation |
233 | default granularity, pixel buffers may straddle virtual allocation |
234 | regions more often than when using the Microsoft allocator. You can |
234 | regions more often than when using the Microsoft allocator. You can |
235 | avoid this by using VirtualAlloc() and VirtualFree() for all pixel |
235 | avoid this by using VirtualAlloc() and VirtualFree() for all pixel |
236 | buffers rather than using malloc(). If this is not possible, |
236 | buffers rather than using malloc(). If this is not possible, |
237 | recompile this malloc with a larger DEFAULT_GRANULARITY. Note: |
237 | recompile this malloc with a larger DEFAULT_GRANULARITY. Note: |
238 | in cases where MSC and gcc (cygwin) are known to differ on WIN32, |
238 | in cases where MSC and gcc (cygwin) are known to differ on WIN32, |
239 | conditions use _MSC_VER to distinguish them. |
239 | conditions use _MSC_VER to distinguish them. |
240 | 240 | ||
241 | DLMALLOC_EXPORT default: extern |
241 | DLMALLOC_EXPORT default: extern |
242 | Defines how public APIs are declared. If you want to export via a |
242 | Defines how public APIs are declared. If you want to export via a |
243 | Windows DLL, you might define this as |
243 | Windows DLL, you might define this as |
244 | #define DLMALLOC_EXPORT extern __declspec(dllexport) |
244 | #define DLMALLOC_EXPORT extern __declspec(dllexport) |
245 | If you want a POSIX ELF shared object, you might use |
245 | If you want a POSIX ELF shared object, you might use |
246 | #define DLMALLOC_EXPORT extern __attribute__((visibility("default"))) |
246 | #define DLMALLOC_EXPORT extern __attribute__((visibility("default"))) |
247 | 247 | ||
248 | MALLOC_ALIGNMENT default: (size_t)(2 * sizeof(void *)) |
248 | MALLOC_ALIGNMENT default: (size_t)(2 * sizeof(void *)) |
249 | Controls the minimum alignment for malloc'ed chunks. It must be a |
249 | Controls the minimum alignment for malloc'ed chunks. It must be a |
250 | power of two and at least 8, even on machines for which smaller |
250 | power of two and at least 8, even on machines for which smaller |
251 | alignments would suffice. It may be defined as larger than this |
251 | alignments would suffice. It may be defined as larger than this |
252 | though. Note however that code and data structures are optimized for |
252 | though. Note however that code and data structures are optimized for |
253 | the case of 8-byte alignment. |
253 | the case of 8-byte alignment. |
254 | 254 | ||
255 | MSPACES default: 0 (false) |
255 | MSPACES default: 0 (false) |
256 | If true, compile in support for independent allocation spaces. |
256 | If true, compile in support for independent allocation spaces. |
257 | This is only supported if HAVE_MMAP is true. |
257 | This is only supported if HAVE_MMAP is true. |
258 | 258 | ||
259 | ONLY_MSPACES default: 0 (false) |
259 | ONLY_MSPACES default: 0 (false) |
260 | If true, only compile in mspace versions, not regular versions. |
260 | If true, only compile in mspace versions, not regular versions. |
261 | 261 | ||
262 | USE_LOCKS default: 0 (false) |
262 | USE_LOCKS default: 0 (false) |
263 | Causes each call to each public routine to be surrounded with |
263 | Causes each call to each public routine to be surrounded with |
264 | pthread or WIN32 mutex lock/unlock. (If set true, this can be |
264 | pthread or WIN32 mutex lock/unlock. (If set true, this can be |
265 | overridden on a per-mspace basis for mspace versions.) If set to a |
265 | overridden on a per-mspace basis for mspace versions.) If set to a |
266 | non-zero value other than 1, locks are used, but their |
266 | non-zero value other than 1, locks are used, but their |
267 | implementation is left out, so lock functions must be supplied manually, |
267 | implementation is left out, so lock functions must be supplied manually, |
268 | as described below. |
268 | as described below. |
269 | 269 | ||
270 | USE_SPIN_LOCKS default: 1 iff USE_LOCKS and spin locks available |
270 | USE_SPIN_LOCKS default: 1 iff USE_LOCKS and spin locks available |
271 | If true, uses custom spin locks for locking. This is currently |
271 | If true, uses custom spin locks for locking. This is currently |
272 | supported only gcc >= 4.1, older gccs on x86 platforms, and recent |
272 | supported only gcc >= 4.1, older gccs on x86 platforms, and recent |
273 | MS compilers. Otherwise, posix locks or win32 critical sections are |
273 | MS compilers. Otherwise, posix locks or win32 critical sections are |
274 | used. |
274 | used. |
275 | 275 | ||
276 | USE_RECURSIVE_LOCKS default: not defined |
276 | USE_RECURSIVE_LOCKS default: not defined |
277 | If defined nonzero, uses recursive (aka reentrant) locks, otherwise |
277 | If defined nonzero, uses recursive (aka reentrant) locks, otherwise |
278 | uses plain mutexes. This is not required for malloc proper, but may |
278 | uses plain mutexes. This is not required for malloc proper, but may |
279 | be needed for layered allocators such as nedmalloc. |
279 | be needed for layered allocators such as nedmalloc. |
280 | 280 | ||
281 | LOCK_AT_FORK default: not defined |
281 | LOCK_AT_FORK default: not defined |
282 | If defined nonzero, performs pthread_atfork upon initialization |
282 | If defined nonzero, performs pthread_atfork upon initialization |
283 | to initialize child lock while holding parent lock. The implementation |
283 | to initialize child lock while holding parent lock. The implementation |
284 | assumes that pthread locks (not custom locks) are being used. In other |
284 | assumes that pthread locks (not custom locks) are being used. In other |
285 | cases, you may need to customize the implementation. |
285 | cases, you may need to customize the implementation. |
286 | 286 | ||
287 | FOOTERS default: 0 |
287 | FOOTERS default: 0 |
288 | If true, provide extra checking and dispatching by placing |
288 | If true, provide extra checking and dispatching by placing |
289 | information in the footers of allocated chunks. This adds |
289 | information in the footers of allocated chunks. This adds |
290 | space and time overhead. |
290 | space and time overhead. |
291 | 291 | ||
292 | INSECURE default: 0 |
292 | INSECURE default: 0 |
293 | If true, omit checks for usage errors and heap space overwrites. |
293 | If true, omit checks for usage errors and heap space overwrites. |
294 | 294 | ||
295 | USE_DL_PREFIX default: NOT defined |
295 | USE_DL_PREFIX default: NOT defined |
296 | Causes compiler to prefix all public routines with the string 'dl'. |
296 | Causes compiler to prefix all public routines with the string 'dl'. |
297 | This can be useful when you only want to use this malloc in one part |
297 | This can be useful when you only want to use this malloc in one part |
298 | of a program, using your regular system malloc elsewhere. |
298 | of a program, using your regular system malloc elsewhere. |
299 | 299 | ||
300 | MALLOC_INSPECT_ALL default: NOT defined |
300 | MALLOC_INSPECT_ALL default: NOT defined |
301 | If defined, compiles malloc_inspect_all and mspace_inspect_all, that |
301 | If defined, compiles malloc_inspect_all and mspace_inspect_all, that |
302 | perform traversal of all heap space. Unless access to these |
302 | perform traversal of all heap space. Unless access to these |
303 | functions is otherwise restricted, you probably do not want to |
303 | functions is otherwise restricted, you probably do not want to |
304 | include them in secure implementations. |
304 | include them in secure implementations. |
305 | 305 | ||
306 | ABORT default: defined as abort() |
306 | ABORT default: defined as abort() |
307 | Defines how to abort on failed checks. On most systems, a failed |
307 | Defines how to abort on failed checks. On most systems, a failed |
308 | check cannot die with an "assert" or even print an informative |
308 | check cannot die with an "assert" or even print an informative |
309 | message, because the underlying print routines in turn call malloc, |
309 | message, because the underlying print routines in turn call malloc, |
310 | which will fail again. Generally, the best policy is to simply call |
310 | which will fail again. Generally, the best policy is to simply call |
311 | abort(). It's not very useful to do more than this because many |
311 | abort(). It's not very useful to do more than this because many |
312 | errors due to overwriting will show up as address faults (null, odd |
312 | errors due to overwriting will show up as address faults (null, odd |
313 | addresses etc) rather than malloc-triggered checks, so will also |
313 | addresses etc) rather than malloc-triggered checks, so will also |
314 | abort. Also, most compilers know that abort() does not return, so |
314 | abort. Also, most compilers know that abort() does not return, so |
315 | can better optimize code conditionally calling it. |
315 | can better optimize code conditionally calling it. |
316 | 316 | ||
317 | PROCEED_ON_ERROR default: defined as 0 (false) |
317 | PROCEED_ON_ERROR default: defined as 0 (false) |
318 | Controls whether detected bad addresses cause them to bypassed |
318 | Controls whether detected bad addresses cause them to bypassed |
319 | rather than aborting. If set, detected bad arguments to free and |
319 | rather than aborting. If set, detected bad arguments to free and |
320 | realloc are ignored. And all bookkeeping information is zeroed out |
320 | realloc are ignored. And all bookkeeping information is zeroed out |
321 | upon a detected overwrite of freed heap space, thus losing the |
321 | upon a detected overwrite of freed heap space, thus losing the |
322 | ability to ever return it from malloc again, but enabling the |
322 | ability to ever return it from malloc again, but enabling the |
323 | application to proceed. If PROCEED_ON_ERROR is defined, the |
323 | application to proceed. If PROCEED_ON_ERROR is defined, the |
324 | static variable malloc_corruption_error_count is compiled in |
324 | static variable malloc_corruption_error_count is compiled in |
325 | and can be examined to see if errors have occurred. This option |
325 | and can be examined to see if errors have occurred. This option |
326 | generates slower code than the default abort policy. |
326 | generates slower code than the default abort policy. |
327 | 327 | ||
328 | DEBUG default: NOT defined |
328 | DEBUG default: NOT defined |
329 | The DEBUG setting is mainly intended for people trying to modify |
329 | The DEBUG setting is mainly intended for people trying to modify |
330 | this code or diagnose problems when porting to new platforms. |
330 | this code or diagnose problems when porting to new platforms. |
331 | However, it may also be able to better isolate user errors than just |
331 | However, it may also be able to better isolate user errors than just |
332 | using runtime checks. The assertions in the check routines spell |
332 | using runtime checks. The assertions in the check routines spell |
333 | out in more detail the assumptions and invariants underlying the |
333 | out in more detail the assumptions and invariants underlying the |
334 | algorithms. The checking is fairly extensive, and will slow down |
334 | algorithms. The checking is fairly extensive, and will slow down |
335 | execution noticeably. Calling malloc_stats or mallinfo with DEBUG |
335 | execution noticeably. Calling malloc_stats or mallinfo with DEBUG |
336 | set will attempt to check every non-mmapped allocated and free chunk |
336 | set will attempt to check every non-mmapped allocated and free chunk |
337 | in the course of computing the summaries. |
337 | in the course of computing the summaries. |
338 | 338 | ||
339 | ABORT_ON_ASSERT_FAILURE default: defined as 1 (true) |
339 | ABORT_ON_ASSERT_FAILURE default: defined as 1 (true) |
340 | Debugging assertion failures can be nearly impossible if your |
340 | Debugging assertion failures can be nearly impossible if your |
341 | version of the assert macro causes malloc to be called, which will |
341 | version of the assert macro causes malloc to be called, which will |
342 | lead to a cascade of further failures, blowing the runtime stack. |
342 | lead to a cascade of further failures, blowing the runtime stack. |
343 | ABORT_ON_ASSERT_FAILURE cause assertions failures to call abort(), |
343 | ABORT_ON_ASSERT_FAILURE cause assertions failures to call abort(), |
344 | which will usually make debugging easier. |
344 | which will usually make debugging easier. |
345 | 345 | ||
346 | MALLOC_FAILURE_ACTION default: sets errno to ENOMEM, or no-op on win32 |
346 | MALLOC_FAILURE_ACTION default: sets errno to ENOMEM, or no-op on win32 |
347 | The action to take before "return 0" when malloc fails to be able to |
347 | The action to take before "return 0" when malloc fails to be able to |
348 | return memory because there is none available. |
348 | return memory because there is none available. |
349 | 349 | ||
350 | HAVE_MORECORE default: 1 (true) unless win32 or ONLY_MSPACES |
350 | HAVE_MORECORE default: 1 (true) unless win32 or ONLY_MSPACES |
351 | True if this system supports sbrk or an emulation of it. |
351 | True if this system supports sbrk or an emulation of it. |
352 | 352 | ||
353 | MORECORE default: sbrk |
353 | MORECORE default: sbrk |
354 | The name of the sbrk-style system routine to call to obtain more |
354 | The name of the sbrk-style system routine to call to obtain more |
355 | memory. See below for guidance on writing custom MORECORE |
355 | memory. See below for guidance on writing custom MORECORE |
356 | functions. The type of the argument to sbrk/MORECORE varies across |
356 | functions. The type of the argument to sbrk/MORECORE varies across |
357 | systems. It cannot be size_t, because it supports negative |
357 | systems. It cannot be size_t, because it supports negative |
358 | arguments, so it is normally the signed type of the same width as |
358 | arguments, so it is normally the signed type of the same width as |
359 | size_t (sometimes declared as "intptr_t"). It doesn't much matter |
359 | size_t (sometimes declared as "intptr_t"). It doesn't much matter |
360 | though. Internally, we only call it with arguments less than half |
360 | though. Internally, we only call it with arguments less than half |
361 | the max value of a size_t, which should work across all reasonable |
361 | the max value of a size_t, which should work across all reasonable |
362 | possibilities, although sometimes generating compiler warnings. |
362 | possibilities, although sometimes generating compiler warnings. |
363 | 363 | ||
364 | MORECORE_CONTIGUOUS default: 1 (true) if HAVE_MORECORE |
364 | MORECORE_CONTIGUOUS default: 1 (true) if HAVE_MORECORE |
365 | If true, take advantage of fact that consecutive calls to MORECORE |
365 | If true, take advantage of fact that consecutive calls to MORECORE |
366 | with positive arguments always return contiguous increasing |
366 | with positive arguments always return contiguous increasing |
367 | addresses. This is true of unix sbrk. It does not hurt too much to |
367 | addresses. This is true of unix sbrk. It does not hurt too much to |
368 | set it true anyway, since malloc copes with non-contiguities. |
368 | set it true anyway, since malloc copes with non-contiguities. |
369 | Setting it false when definitely non-contiguous saves time |
369 | Setting it false when definitely non-contiguous saves time |
370 | and possibly wasted space it would take to discover this though. |
370 | and possibly wasted space it would take to discover this though. |
371 | 371 | ||
372 | MORECORE_CANNOT_TRIM default: NOT defined |
372 | MORECORE_CANNOT_TRIM default: NOT defined |
373 | True if MORECORE cannot release space back to the system when given |
373 | True if MORECORE cannot release space back to the system when given |
374 | negative arguments. This is generally necessary only if you are |
374 | negative arguments. This is generally necessary only if you are |
375 | using a hand-crafted MORECORE function that cannot handle negative |
375 | using a hand-crafted MORECORE function that cannot handle negative |
376 | arguments. |
376 | arguments. |
377 | 377 | ||
378 | NO_SEGMENT_TRAVERSAL default: 0 |
378 | NO_SEGMENT_TRAVERSAL default: 0 |
379 | If non-zero, suppresses traversals of memory segments |
379 | If non-zero, suppresses traversals of memory segments |
380 | returned by either MORECORE or CALL_MMAP. This disables |
380 | returned by either MORECORE or CALL_MMAP. This disables |
381 | merging of segments that are contiguous, and selectively |
381 | merging of segments that are contiguous, and selectively |
382 | releasing them to the OS if unused, but bounds execution times. |
382 | releasing them to the OS if unused, but bounds execution times. |
383 | 383 | ||
384 | HAVE_MMAP default: 1 (true) |
384 | HAVE_MMAP default: 1 (true) |
385 | True if this system supports mmap or an emulation of it. If so, and |
385 | True if this system supports mmap or an emulation of it. If so, and |
386 | HAVE_MORECORE is not true, MMAP is used for all system |
386 | HAVE_MORECORE is not true, MMAP is used for all system |
387 | allocation. If set and HAVE_MORECORE is true as well, MMAP is |
387 | allocation. If set and HAVE_MORECORE is true as well, MMAP is |
388 | primarily used to directly allocate very large blocks. It is also |
388 | primarily used to directly allocate very large blocks. It is also |
389 | used as a backup strategy in cases where MORECORE fails to provide |
389 | used as a backup strategy in cases where MORECORE fails to provide |
390 | space from system. Note: A single call to MUNMAP is assumed to be |
390 | space from system. Note: A single call to MUNMAP is assumed to be |
391 | able to unmap memory that may have be allocated using multiple calls |
391 | able to unmap memory that may have be allocated using multiple calls |
392 | to MMAP, so long as they are adjacent. |
392 | to MMAP, so long as they are adjacent. |
393 | 393 | ||
394 | HAVE_MREMAP default: 1 on linux, else 0 |
394 | HAVE_MREMAP default: 1 on linux, else 0 |
395 | If true realloc() uses mremap() to re-allocate large blocks and |
395 | If true realloc() uses mremap() to re-allocate large blocks and |
396 | extend or shrink allocation spaces. |
396 | extend or shrink allocation spaces. |
397 | 397 | ||
398 | MMAP_CLEARS default: 1 except on WINCE. |
398 | MMAP_CLEARS default: 1 except on WINCE. |
399 | True if mmap clears memory so calloc doesn't need to. This is true |
399 | True if mmap clears memory so calloc doesn't need to. This is true |
400 | for standard unix mmap using /dev/zero and on WIN32 except for WINCE. |
400 | for standard unix mmap using /dev/zero and on WIN32 except for WINCE. |
401 | 401 | ||
402 | USE_BUILTIN_FFS default: 0 (i.e., not used) |
402 | USE_BUILTIN_FFS default: 0 (i.e., not used) |
403 | Causes malloc to use the builtin ffs() function to compute indices. |
403 | Causes malloc to use the builtin ffs() function to compute indices. |
404 | Some compilers may recognize and intrinsify ffs to be faster than the |
404 | Some compilers may recognize and intrinsify ffs to be faster than the |
405 | supplied C version. Also, the case of x86 using gcc is special-cased |
405 | supplied C version. Also, the case of x86 using gcc is special-cased |
406 | to an asm instruction, so is already as fast as it can be, and so |
406 | to an asm instruction, so is already as fast as it can be, and so |
407 | this setting has no effect. Similarly for Win32 under recent MS compilers. |
407 | this setting has no effect. Similarly for Win32 under recent MS compilers. |
408 | (On most x86s, the asm version is only slightly faster than the C version.) |
408 | (On most x86s, the asm version is only slightly faster than the C version.) |
409 | 409 | ||
410 | malloc_getpagesize default: derive from system includes, or 4096. |
410 | malloc_getpagesize default: derive from system includes, or 4096. |
411 | The system page size. To the extent possible, this malloc manages |
411 | The system page size. To the extent possible, this malloc manages |
412 | memory from the system in page-size units. This may be (and |
412 | memory from the system in page-size units. This may be (and |
413 | usually is) a function rather than a constant. This is ignored |
413 | usually is) a function rather than a constant. This is ignored |
414 | if WIN32, where page size is determined using getSystemInfo during |
414 | if WIN32, where page size is determined using getSystemInfo during |
415 | initialization. |
415 | initialization. |
416 | 416 | ||
417 | USE_DEV_RANDOM default: 0 (i.e., not used) |
417 | USE_DEV_RANDOM default: 0 (i.e., not used) |
418 | Causes malloc to use /dev/random to initialize secure magic seed for |
418 | Causes malloc to use /dev/random to initialize secure magic seed for |
419 | stamping footers. Otherwise, the current time is used. |
419 | stamping footers. Otherwise, the current time is used. |
420 | 420 | ||
421 | NO_MALLINFO default: 0 |
421 | NO_MALLINFO default: 0 |
422 | If defined, don't compile "mallinfo". This can be a simple way |
422 | If defined, don't compile "mallinfo". This can be a simple way |
423 | of dealing with mismatches between system declarations and |
423 | of dealing with mismatches between system declarations and |
424 | those in this file. |
424 | those in this file. |
425 | 425 | ||
426 | MALLINFO_FIELD_TYPE default: size_t |
426 | MALLINFO_FIELD_TYPE default: size_t |
427 | The type of the fields in the mallinfo struct. This was originally |
427 | The type of the fields in the mallinfo struct. This was originally |
428 | defined as "int" in SVID etc, but is more usefully defined as |
428 | defined as "int" in SVID etc, but is more usefully defined as |
429 | size_t. The value is used only if HAVE_USR_INCLUDE_MALLOC_H is not set |
429 | size_t. The value is used only if HAVE_USR_INCLUDE_MALLOC_H is not set |
430 | 430 | ||
431 | NO_MALLOC_STATS default: 0 |
431 | NO_MALLOC_STATS default: 0 |
432 | If defined, don't compile "malloc_stats". This avoids calls to |
432 | If defined, don't compile "malloc_stats". This avoids calls to |
433 | fprintf and bringing in stdio dependencies you might not want. |
433 | fprintf and bringing in stdio dependencies you might not want. |
434 | 434 | ||
435 | REALLOC_ZERO_BYTES_FREES default: not defined |
435 | REALLOC_ZERO_BYTES_FREES default: not defined |
436 | This should be set if a call to realloc with zero bytes should |
436 | This should be set if a call to realloc with zero bytes should |
437 | be the same as a call to free. Some people think it should. Otherwise, |
437 | be the same as a call to free. Some people think it should. Otherwise, |
438 | since this malloc returns a unique pointer for malloc(0), so does |
438 | since this malloc returns a unique pointer for malloc(0), so does |
439 | realloc(p, 0). |
439 | realloc(p, 0). |
440 | 440 | ||
441 | LACKS_UNISTD_H, LACKS_FCNTL_H, LACKS_SYS_PARAM_H, LACKS_SYS_MMAN_H |
441 | LACKS_UNISTD_H, LACKS_FCNTL_H, LACKS_SYS_PARAM_H, LACKS_SYS_MMAN_H |
442 | LACKS_STRINGS_H, LACKS_STRING_H, LACKS_SYS_TYPES_H, LACKS_ERRNO_H |
442 | LACKS_STRINGS_H, LACKS_STRING_H, LACKS_SYS_TYPES_H, LACKS_ERRNO_H |
443 | LACKS_STDLIB_H LACKS_SCHED_H LACKS_TIME_H default: NOT defined unless on WIN32 |
443 | LACKS_STDLIB_H LACKS_SCHED_H LACKS_TIME_H default: NOT defined unless on WIN32 |
444 | Define these if your system does not have these header files. |
444 | Define these if your system does not have these header files. |
445 | You might need to manually insert some of the declarations they provide. |
445 | You might need to manually insert some of the declarations they provide. |
446 | 446 | ||
447 | DEFAULT_GRANULARITY default: page size if MORECORE_CONTIGUOUS, |
447 | DEFAULT_GRANULARITY default: page size if MORECORE_CONTIGUOUS, |
448 | system_info.dwAllocationGranularity in WIN32, |
448 | system_info.dwAllocationGranularity in WIN32, |
449 | otherwise 64K. |
449 | otherwise 64K. |
450 | Also settable using mallopt(M_GRANULARITY, x) |
450 | Also settable using mallopt(M_GRANULARITY, x) |
451 | The unit for allocating and deallocating memory from the system. On |
451 | The unit for allocating and deallocating memory from the system. On |
452 | most systems with contiguous MORECORE, there is no reason to |
452 | most systems with contiguous MORECORE, there is no reason to |
453 | make this more than a page. However, systems with MMAP tend to |
453 | make this more than a page. However, systems with MMAP tend to |
454 | either require or encourage larger granularities. You can increase |
454 | either require or encourage larger granularities. You can increase |
455 | this value to prevent system allocation functions to be called so |
455 | this value to prevent system allocation functions to be called so |
456 | often, especially if they are slow. The value must be at least one |
456 | often, especially if they are slow. The value must be at least one |
457 | page and must be a power of two. Setting to 0 causes initialization |
457 | page and must be a power of two. Setting to 0 causes initialization |
458 | to either page size or win32 region size. (Note: In previous |
458 | to either page size or win32 region size. (Note: In previous |
459 | versions of malloc, the equivalent of this option was called |
459 | versions of malloc, the equivalent of this option was called |
460 | "TOP_PAD") |
460 | "TOP_PAD") |
461 | 461 | ||
462 | DEFAULT_TRIM_THRESHOLD default: 2MB |
462 | DEFAULT_TRIM_THRESHOLD default: 2MB |
463 | Also settable using mallopt(M_TRIM_THRESHOLD, x) |
463 | Also settable using mallopt(M_TRIM_THRESHOLD, x) |
464 | The maximum amount of unused top-most memory to keep before |
464 | The maximum amount of unused top-most memory to keep before |
465 | releasing via malloc_trim in free(). Automatic trimming is mainly |
465 | releasing via malloc_trim in free(). Automatic trimming is mainly |
466 | useful in long-lived programs using contiguous MORECORE. Because |
466 | useful in long-lived programs using contiguous MORECORE. Because |
467 | trimming via sbrk can be slow on some systems, and can sometimes be |
467 | trimming via sbrk can be slow on some systems, and can sometimes be |
468 | wasteful (in cases where programs immediately afterward allocate |
468 | wasteful (in cases where programs immediately afterward allocate |
469 | more large chunks) the value should be high enough so that your |
469 | more large chunks) the value should be high enough so that your |
470 | overall system performance would improve by releasing this much |
470 | overall system performance would improve by releasing this much |
471 | memory. As a rough guide, you might set to a value close to the |
471 | memory. As a rough guide, you might set to a value close to the |
472 | average size of a process (program) running on your system. |
472 | average size of a process (program) running on your system. |
473 | Releasing this much memory would allow such a process to run in |
473 | Releasing this much memory would allow such a process to run in |
474 | memory. Generally, it is worth tuning trim thresholds when a |
474 | memory. Generally, it is worth tuning trim thresholds when a |
475 | program undergoes phases where several large chunks are allocated |
475 | program undergoes phases where several large chunks are allocated |
476 | and released in ways that can reuse each other's storage, perhaps |
476 | and released in ways that can reuse each other's storage, perhaps |
477 | mixed with phases where there are no such chunks at all. The trim |
477 | mixed with phases where there are no such chunks at all. The trim |
478 | value must be greater than page size to have any useful effect. To |
478 | value must be greater than page size to have any useful effect. To |
479 | disable trimming completely, you can set to MAX_SIZE_T. Note that the trick |
479 | disable trimming completely, you can set to MAX_SIZE_T. Note that the trick |
480 | some people use of mallocing a huge space and then freeing it at |
480 | some people use of mallocing a huge space and then freeing it at |
481 | program startup, in an attempt to reserve system memory, doesn't |
481 | program startup, in an attempt to reserve system memory, doesn't |
482 | have the intended effect under automatic trimming, since that memory |
482 | have the intended effect under automatic trimming, since that memory |
483 | will immediately be returned to the system. |
483 | will immediately be returned to the system. |
484 | 484 | ||
485 | DEFAULT_MMAP_THRESHOLD default: 256K |
485 | DEFAULT_MMAP_THRESHOLD default: 256K |
486 | Also settable using mallopt(M_MMAP_THRESHOLD, x) |
486 | Also settable using mallopt(M_MMAP_THRESHOLD, x) |
487 | The request size threshold for using MMAP to directly service a |
487 | The request size threshold for using MMAP to directly service a |
488 | request. Requests of at least this size that cannot be allocated |
488 | request. Requests of at least this size that cannot be allocated |
489 | using already-existing space will be serviced via mmap. (If enough |
489 | using already-existing space will be serviced via mmap. (If enough |
490 | normal freed space already exists it is used instead.) Using mmap |
490 | normal freed space already exists it is used instead.) Using mmap |
491 | segregates relatively large chunks of memory so that they can be |
491 | segregates relatively large chunks of memory so that they can be |
492 | individually obtained and released from the host system. A request |
492 | individually obtained and released from the host system. A request |
493 | serviced through mmap is never reused by any other request (at least |
493 | serviced through mmap is never reused by any other request (at least |
494 | not directly; the system may just so happen to remap successive |
494 | not directly; the system may just so happen to remap successive |
495 | requests to the same locations). Segregating space in this way has |
495 | requests to the same locations). Segregating space in this way has |
496 | the benefits that: Mmapped space can always be individually released |
496 | the benefits that: Mmapped space can always be individually released |
497 | back to the system, which helps keep the system level memory demands |
497 | back to the system, which helps keep the system level memory demands |
498 | of a long-lived program low. Also, mapped memory doesn't become |
498 | of a long-lived program low. Also, mapped memory doesn't become |
499 | `locked' between other chunks, as can happen with normally allocated |
499 | `locked' between other chunks, as can happen with normally allocated |
500 | chunks, which means that even trimming via malloc_trim would not |
500 | chunks, which means that even trimming via malloc_trim would not |
501 | release them. However, it has the disadvantage that the space |
501 | release them. However, it has the disadvantage that the space |
502 | cannot be reclaimed, consolidated, and then used to service later |
502 | cannot be reclaimed, consolidated, and then used to service later |
503 | requests, as happens with normal chunks. The advantages of mmap |
503 | requests, as happens with normal chunks. The advantages of mmap |
504 | nearly always outweigh disadvantages for "large" chunks, but the |
504 | nearly always outweigh disadvantages for "large" chunks, but the |
505 | value of "large" may vary across systems. The default is an |
505 | value of "large" may vary across systems. The default is an |
506 | empirically derived value that works well in most systems. You can |
506 | empirically derived value that works well in most systems. You can |
507 | disable mmap by setting to MAX_SIZE_T. |
507 | disable mmap by setting to MAX_SIZE_T. |
508 | 508 | ||
509 | MAX_RELEASE_CHECK_RATE default: 4095 unless not HAVE_MMAP |
509 | MAX_RELEASE_CHECK_RATE default: 4095 unless not HAVE_MMAP |
510 | The number of consolidated frees between checks to release |
510 | The number of consolidated frees between checks to release |
511 | unused segments when freeing. When using non-contiguous segments, |
511 | unused segments when freeing. When using non-contiguous segments, |
512 | especially with multiple mspaces, checking only for topmost space |
512 | especially with multiple mspaces, checking only for topmost space |
513 | doesn't always suffice to trigger trimming. To compensate for this, |
513 | doesn't always suffice to trigger trimming. To compensate for this, |
514 | free() will, with a period of MAX_RELEASE_CHECK_RATE (or the |
514 | free() will, with a period of MAX_RELEASE_CHECK_RATE (or the |
515 | current number of segments, if greater) try to release unused |
515 | current number of segments, if greater) try to release unused |
516 | segments to the OS when freeing chunks that result in |
516 | segments to the OS when freeing chunks that result in |
517 | consolidation. The best value for this parameter is a compromise |
517 | consolidation. The best value for this parameter is a compromise |
518 | between slowing down frees with relatively costly checks that |
518 | between slowing down frees with relatively costly checks that |
519 | rarely trigger versus holding on to unused memory. To effectively |
519 | rarely trigger versus holding on to unused memory. To effectively |
520 | disable, set to MAX_SIZE_T. This may lead to a very slight speed |
520 | disable, set to MAX_SIZE_T. This may lead to a very slight speed |
521 | improvement at the expense of carrying around more memory. |
521 | improvement at the expense of carrying around more memory. |
522 | */ |
522 | */ |
523 | 523 | ||
524 | #include |
524 | #include |
525 | #include |
525 | #include |
526 | #include |
526 | #include |
527 | 527 | ||
528 | /* Version identifier to allow people to support multiple versions */ |
528 | /* Version identifier to allow people to support multiple versions */ |
529 | #ifndef DLMALLOC_VERSION |
529 | #ifndef DLMALLOC_VERSION |
530 | #define DLMALLOC_VERSION 20806 |
530 | #define DLMALLOC_VERSION 20806 |
531 | #endif /* DLMALLOC_VERSION */ |
531 | #endif /* DLMALLOC_VERSION */ |
532 | 532 | ||
533 | 533 | ||
534 | /* |
534 | /* |
535 | malloc(size_t n) |
535 | malloc(size_t n) |
536 | Returns a pointer to a newly allocated chunk of at least n bytes, or |
536 | Returns a pointer to a newly allocated chunk of at least n bytes, or |
537 | null if no space is available, in which case errno is set to ENOMEM |
537 | null if no space is available, in which case errno is set to ENOMEM |
538 | on ANSI C systems. |
538 | on ANSI C systems. |
539 | 539 | ||
540 | If n is zero, malloc returns a minimum-sized chunk. (The minimum |
540 | If n is zero, malloc returns a minimum-sized chunk. (The minimum |
541 | size is 16 bytes on most 32bit systems, and 32 bytes on 64bit |
541 | size is 16 bytes on most 32bit systems, and 32 bytes on 64bit |
542 | systems.) Note that size_t is an unsigned type, so calls with |
542 | systems.) Note that size_t is an unsigned type, so calls with |
543 | arguments that would be negative if signed are interpreted as |
543 | arguments that would be negative if signed are interpreted as |
544 | requests for huge amounts of space, which will often fail. The |
544 | requests for huge amounts of space, which will often fail. The |
545 | maximum supported value of n differs across systems, but is in all |
545 | maximum supported value of n differs across systems, but is in all |
546 | cases less than the maximum representable value of a size_t. |
546 | cases less than the maximum representable value of a size_t. |
547 | */ |
547 | */ |
548 | 548 | ||
549 | /* |
549 | /* |
550 | free(void* p) |
550 | free(void* p) |
551 | Releases the chunk of memory pointed to by p, that had been previously |
551 | Releases the chunk of memory pointed to by p, that had been previously |
552 | allocated using malloc or a related routine such as realloc. |
552 | allocated using malloc or a related routine such as realloc. |
553 | It has no effect if p is null. If p was not malloced or already |
553 | It has no effect if p is null. If p was not malloced or already |
554 | freed, free(p) will by default cause the current program to abort. |
554 | freed, free(p) will by default cause the current program to abort. |
555 | */ |
555 | */ |
556 | 556 | ||
557 | /* |
557 | /* |
558 | calloc(size_t n_elements, size_t element_size); |
558 | calloc(size_t n_elements, size_t element_size); |
559 | Returns a pointer to n_elements * element_size bytes, with all locations |
559 | Returns a pointer to n_elements * element_size bytes, with all locations |
560 | set to zero. |
560 | set to zero. |
561 | */ |
561 | */ |
562 | 562 | ||
563 | /* |
563 | /* |
564 | realloc(void* p, size_t n) |
564 | realloc(void* p, size_t n) |
565 | Returns a pointer to a chunk of size n that contains the same data |
565 | Returns a pointer to a chunk of size n that contains the same data |
566 | as does chunk p up to the minimum of (n, p's size) bytes, or null |
566 | as does chunk p up to the minimum of (n, p's size) bytes, or null |
567 | if no space is available. |
567 | if no space is available. |
568 | 568 | ||
569 | The returned pointer may or may not be the same as p. The algorithm |
569 | The returned pointer may or may not be the same as p. The algorithm |
570 | prefers extending p in most cases when possible, otherwise it |
570 | prefers extending p in most cases when possible, otherwise it |
571 | employs the equivalent of a malloc-copy-free sequence. |
571 | employs the equivalent of a malloc-copy-free sequence. |
572 | 572 | ||
573 | If p is null, realloc is equivalent to malloc. |
573 | If p is null, realloc is equivalent to malloc. |
574 | 574 | ||
575 | If space is not available, realloc returns null, errno is set (if on |
575 | If space is not available, realloc returns null, errno is set (if on |
576 | ANSI) and p is NOT freed. |
576 | ANSI) and p is NOT freed. |
577 | 577 | ||
578 | if n is for fewer bytes than already held by p, the newly unused |
578 | if n is for fewer bytes than already held by p, the newly unused |
579 | space is lopped off and freed if possible. realloc with a size |
579 | space is lopped off and freed if possible. realloc with a size |
580 | argument of zero (re)allocates a minimum-sized chunk. |
580 | argument of zero (re)allocates a minimum-sized chunk. |
581 | 581 | ||
582 | The old unix realloc convention of allowing the last-free'd chunk |
582 | The old unix realloc convention of allowing the last-free'd chunk |
583 | to be used as an argument to realloc is not supported. |
583 | to be used as an argument to realloc is not supported. |
584 | */ |
584 | */ |
585 | /* |
585 | /* |
586 | memalign(size_t alignment, size_t n); |
586 | memalign(size_t alignment, size_t n); |
587 | Returns a pointer to a newly allocated chunk of n bytes, aligned |
587 | Returns a pointer to a newly allocated chunk of n bytes, aligned |
588 | in accord with the alignment argument. |
588 | in accord with the alignment argument. |
589 | 589 | ||
590 | The alignment argument should be a power of two. If the argument is |
590 | The alignment argument should be a power of two. If the argument is |
591 | not a power of two, the nearest greater power is used. |
591 | not a power of two, the nearest greater power is used. |
592 | 8-byte alignment is guaranteed by normal malloc calls, so don't |
592 | 8-byte alignment is guaranteed by normal malloc calls, so don't |
593 | bother calling memalign with an argument of 8 or less. |
593 | bother calling memalign with an argument of 8 or less. |
594 | 594 | ||
595 | Overreliance on memalign is a sure way to fragment space. |
595 | Overreliance on memalign is a sure way to fragment space. |
596 | */ |
596 | */ |
597 | 597 | ||
598 | 598 | ||
599 | #define DEBUG 1 |
599 | #define DEBUG 1 |
600 | 600 | ||
601 | 601 | ||
602 | 602 | ||
603 | 603 | ||
604 | 604 | ||
605 | 605 | ||
606 | 606 | ||
607 | 607 | ||
608 | 608 | ||
609 | 609 | ||
610 | 610 | ||
611 | 611 | ||
612 | #define assert(x) |
612 | #define assert(x) |
613 | 613 | ||
614 | #define MAX_SIZE_T (~(size_t)0) |
614 | #define MAX_SIZE_T (~(size_t)0) |
615 | 615 | ||
616 | #define CALL_DIRECT_MMAP(s) MMAP_DEFAULT(s) |
616 | #define CALL_DIRECT_MMAP(s) MMAP_DEFAULT(s) |
617 | 617 | ||
618 | /* ------------------- size_t and alignment properties -------------------- */ |
618 | /* ------------------- size_t and alignment properties -------------------- */ |
619 | 619 | ||
620 | /* The byte and bit size of a size_t */ |
620 | /* The byte and bit size of a size_t */ |
621 | #define SIZE_T_SIZE (sizeof(size_t)) |
621 | #define SIZE_T_SIZE (sizeof(size_t)) |
622 | #define SIZE_T_BITSIZE (sizeof(size_t) << 3) |
622 | #define SIZE_T_BITSIZE (sizeof(size_t) << 3) |
623 | 623 | ||
624 | /* Some constants coerced to size_t */ |
624 | /* Some constants coerced to size_t */ |
625 | /* Annoying but necessary to avoid errors on some platforms */ |
625 | /* Annoying but necessary to avoid errors on some platforms */ |
626 | #define SIZE_T_ZERO ((size_t)0) |
626 | #define SIZE_T_ZERO ((size_t)0) |
627 | #define SIZE_T_ONE ((size_t)1) |
627 | #define SIZE_T_ONE ((size_t)1) |
628 | #define SIZE_T_TWO ((size_t)2) |
628 | #define SIZE_T_TWO ((size_t)2) |
629 | #define SIZE_T_FOUR ((size_t)4) |
629 | #define SIZE_T_FOUR ((size_t)4) |
630 | #define TWO_SIZE_T_SIZES (SIZE_T_SIZE<<1) |
630 | #define TWO_SIZE_T_SIZES (SIZE_T_SIZE<<1) |
631 | #define FOUR_SIZE_T_SIZES (SIZE_T_SIZE<<2) |
631 | #define FOUR_SIZE_T_SIZES (SIZE_T_SIZE<<2) |
632 | #define SIX_SIZE_T_SIZES (FOUR_SIZE_T_SIZES+TWO_SIZE_T_SIZES) |
632 | #define SIX_SIZE_T_SIZES (FOUR_SIZE_T_SIZES+TWO_SIZE_T_SIZES) |
633 | #define HALF_MAX_SIZE_T (MAX_SIZE_T / 2U) |
633 | #define HALF_MAX_SIZE_T (MAX_SIZE_T / 2U) |
634 | 634 | ||
635 | #define USE_LOCK_BIT (2U) |
635 | #define USE_LOCK_BIT (2U) |
636 | #define USE_MMAP_BIT (SIZE_T_ONE) |
636 | #define USE_MMAP_BIT (SIZE_T_ONE) |
637 | #define USE_NONCONTIGUOUS_BIT (4U) |
637 | #define USE_NONCONTIGUOUS_BIT (4U) |
638 | 638 | ||
639 | /* segment bit set in create_mspace_with_base */ |
639 | /* segment bit set in create_mspace_with_base */ |
640 | #define EXTERN_BIT (8U) |
640 | #define EXTERN_BIT (8U) |
641 | 641 | ||
642 | #define HAVE_MMAP 1 |
642 | #define HAVE_MMAP 1 |
643 | #define HAVE_MORECORE 0 |
643 | #define HAVE_MORECORE 0 |
644 | #define MORECORE_CANNOT_TRIM 1 |
644 | #define MORECORE_CANNOT_TRIM 1 |
645 | #define CALL_MMAP(s) MMAP_DEFAULT(s) |
645 | #define CALL_MMAP(s) MMAP_DEFAULT(s) |
646 | #define CALL_MUNMAP(a, s) MUNMAP_DEFAULT((a), (s)) |
646 | #define CALL_MUNMAP(a, s) MUNMAP_DEFAULT((a), (s)) |
647 | #define CALL_MREMAP(addr, osz, nsz, mv) MFAIL |
647 | #define CALL_MREMAP(addr, osz, nsz, mv) MFAIL |
648 | #define MAX_RELEASE_CHECK_RATE 4095 |
648 | #define MAX_RELEASE_CHECK_RATE 4095 |
649 | #define NO_SEGMENT_TRAVERSAL 1 |
649 | #define NO_SEGMENT_TRAVERSAL 1 |
650 | #define MALLOC_ALIGNMENT ((size_t)8U) |
650 | #define MALLOC_ALIGNMENT ((size_t)8U) |
651 | #define CHUNK_OVERHEAD (SIZE_T_SIZE) |
651 | #define CHUNK_OVERHEAD (SIZE_T_SIZE) |
652 | #define DEFAULT_GRANULARITY ((size_t)128U * (size_t)1024U) |
652 | #define DEFAULT_GRANULARITY ((size_t)256U * (size_t)1024U) |
653 | #define DEFAULT_MMAP_THRESHOLD ((size_t)512U * (size_t)1024U) |
653 | #define DEFAULT_MMAP_THRESHOLD ((size_t)1024U * (size_t)1024U) |
654 | #define DEFAULT_TRIM_THRESHOLD ((size_t)1024U * (size_t)1024U) |
654 | #define DEFAULT_TRIM_THRESHOLD ((size_t)2048U * (size_t)1024U) |
655 | 655 | ||
656 | /* The bit mask value corresponding to MALLOC_ALIGNMENT */ |
656 | /* The bit mask value corresponding to MALLOC_ALIGNMENT */ |
657 | #define CHUNK_ALIGN_MASK (MALLOC_ALIGNMENT - SIZE_T_ONE) |
657 | #define CHUNK_ALIGN_MASK (MALLOC_ALIGNMENT - SIZE_T_ONE) |
658 | 658 | ||
659 | /* True if address a has acceptable alignment */ |
659 | /* True if address a has acceptable alignment */ |
660 | #define is_aligned(A) (((size_t)((A)) & (CHUNK_ALIGN_MASK)) == 0) |
660 | #define is_aligned(A) (((size_t)((A)) & (CHUNK_ALIGN_MASK)) == 0) |
661 | 661 | ||
662 | /* the number of bytes to offset an address to align it */ |
662 | /* the number of bytes to offset an address to align it */ |
663 | #define align_offset(A)\ |
663 | #define align_offset(A)\ |
664 | ((((size_t)(A) & CHUNK_ALIGN_MASK) == 0)? 0 :\ |
664 | ((((size_t)(A) & CHUNK_ALIGN_MASK) == 0)? 0 :\ |
665 | ((MALLOC_ALIGNMENT - ((size_t)(A) & CHUNK_ALIGN_MASK)) & CHUNK_ALIGN_MASK)) |
665 | ((MALLOC_ALIGNMENT - ((size_t)(A) & CHUNK_ALIGN_MASK)) & CHUNK_ALIGN_MASK)) |
666 | 666 | ||
667 | /* -------------------------- MMAP preliminaries ------------------------- */ |
667 | /* -------------------------- MMAP preliminaries ------------------------- */ |
668 | 668 | ||
669 | /* |
669 | /* |
670 | If HAVE_MORECORE or HAVE_MMAP are false, we just define calls and |
670 | If HAVE_MORECORE or HAVE_MMAP are false, we just define calls and |
671 | checks to fail so compiler optimizer can delete code rather than |
671 | checks to fail so compiler optimizer can delete code rather than |
672 | using so many "#if"s. |
672 | using so many "#if"s. |
673 | */ |
673 | */ |
674 | 674 | ||
675 | 675 | ||
676 | /* MORECORE and MMAP must return MFAIL on failure */ |
676 | /* MORECORE and MMAP must return MFAIL on failure */ |
677 | #define MFAIL ((void*)(MAX_SIZE_T)) |
677 | #define MFAIL ((void*)(MAX_SIZE_T)) |
678 | #define CMFAIL ((char*)(MFAIL)) /* defined for convenience */ |
678 | #define CMFAIL ((char*)(MFAIL)) /* defined for convenience */ |
679 | 679 | ||
680 | #define should_trim(M,s) (0) |
680 | #define should_trim(M,s) (0) |
681 | 681 | ||
682 | 682 | ||
683 | 683 | ||
684 | /* --------------------------- Lock preliminaries ------------------------ */ |
684 | /* --------------------------- Lock preliminaries ------------------------ */ |
685 | 685 | ||
686 | /* |
686 | /* |
687 | When locks are defined, there is one global lock, plus |
687 | When locks are defined, there is one global lock, plus |
688 | one per-mspace lock. |
688 | one per-mspace lock. |
689 | 689 | ||
690 | The global lock_ensures that mparams.magic and other unique |
690 | The global lock_ensures that mparams.magic and other unique |
691 | mparams values are initialized only once. It also protects |
691 | mparams values are initialized only once. It also protects |
692 | sequences of calls to MORECORE. In many cases sys_alloc requires |
692 | sequences of calls to MORECORE. In many cases sys_alloc requires |
693 | two calls, that should not be interleaved with calls by other |
693 | two calls, that should not be interleaved with calls by other |
694 | threads. This does not protect against direct calls to MORECORE |
694 | threads. This does not protect against direct calls to MORECORE |
695 | by other threads not using this lock, so there is still code to |
695 | by other threads not using this lock, so there is still code to |
696 | cope the best we can on interference. |
696 | cope the best we can on interference. |
697 | 697 | ||
698 | Per-mspace locks surround calls to malloc, free, etc. |
698 | Per-mspace locks surround calls to malloc, free, etc. |
699 | By default, locks are simple non-reentrant mutexes. |
699 | By default, locks are simple non-reentrant mutexes. |
700 | 700 | ||
701 | Because lock-protected regions generally have bounded times, it is |
701 | Because lock-protected regions generally have bounded times, it is |
702 | OK to use the supplied simple spinlocks. Spinlocks are likely to |
702 | OK to use the supplied simple spinlocks. Spinlocks are likely to |
703 | improve performance for lightly contended applications, but worsen |
703 | improve performance for lightly contended applications, but worsen |
704 | performance under heavy contention. |
704 | performance under heavy contention. |
705 | 705 | ||
706 | If USE_LOCKS is > 1, the definitions of lock routines here are |
706 | If USE_LOCKS is > 1, the definitions of lock routines here are |
707 | bypassed, in which case you will need to define the type MLOCK_T, |
707 | bypassed, in which case you will need to define the type MLOCK_T, |
708 | and at least INITIAL_LOCK, DESTROY_LOCK, ACQUIRE_LOCK, RELEASE_LOCK |
708 | and at least INITIAL_LOCK, DESTROY_LOCK, ACQUIRE_LOCK, RELEASE_LOCK |
709 | and TRY_LOCK. You must also declare a |
709 | and TRY_LOCK. You must also declare a |
710 | static MLOCK_T malloc_global_mutex = { initialization values };. |
710 | static MLOCK_T malloc_global_mutex = { initialization values };. |
711 | 711 | ||
712 | */ |
712 | */ |
713 | 713 | ||
714 | static DEFINE_MUTEX(malloc_global_mutex); |
714 | static DEFINE_MUTEX(malloc_global_mutex); |
715 | 715 | ||
716 | #define ACQUIRE_MALLOC_GLOBAL_LOCK() MutexLock(&malloc_global_mutex); |
716 | #define ACQUIRE_MALLOC_GLOBAL_LOCK() MutexLock(&malloc_global_mutex); |
717 | #define RELEASE_MALLOC_GLOBAL_LOCK() MutexUnlock(&malloc_global_mutex); |
717 | #define RELEASE_MALLOC_GLOBAL_LOCK() MutexUnlock(&malloc_global_mutex); |
718 | 718 | ||
719 | 719 | ||
720 | /* ----------------------- Chunk representations ------------------------ */ |
720 | /* ----------------------- Chunk representations ------------------------ */ |
721 | 721 | ||
722 | /* |
722 | /* |
723 | (The following includes lightly edited explanations by Colin Plumb.) |
723 | (The following includes lightly edited explanations by Colin Plumb.) |
724 | 724 | ||
725 | The malloc_chunk declaration below is misleading (but accurate and |
725 | The malloc_chunk declaration below is misleading (but accurate and |
726 | necessary). It declares a "view" into memory allowing access to |
726 | necessary). It declares a "view" into memory allowing access to |
727 | necessary fields at known offsets from a given base. |
727 | necessary fields at known offsets from a given base. |
728 | 728 | ||
729 | Chunks of memory are maintained using a `boundary tag' method as |
729 | Chunks of memory are maintained using a `boundary tag' method as |
730 | originally described by Knuth. (See the paper by Paul Wilson |
730 | originally described by Knuth. (See the paper by Paul Wilson |
731 | ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a survey of such |
731 | ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a survey of such |
732 | techniques.) Sizes of free chunks are stored both in the front of |
732 | techniques.) Sizes of free chunks are stored both in the front of |
733 | each chunk and at the end. This makes consolidating fragmented |
733 | each chunk and at the end. This makes consolidating fragmented |
734 | chunks into bigger chunks fast. The head fields also hold bits |
734 | chunks into bigger chunks fast. The head fields also hold bits |
735 | representing whether chunks are free or in use. |
735 | representing whether chunks are free or in use. |
736 | 736 | ||
737 | Here are some pictures to make it clearer. They are "exploded" to |
737 | Here are some pictures to make it clearer. They are "exploded" to |
738 | show that the state of a chunk can be thought of as extending from |
738 | show that the state of a chunk can be thought of as extending from |
739 | the high 31 bits of the head field of its header through the |
739 | the high 31 bits of the head field of its header through the |
740 | prev_foot and PINUSE_BIT bit of the following chunk header. |
740 | prev_foot and PINUSE_BIT bit of the following chunk header. |
741 | 741 | ||
742 | A chunk that's in use looks like: |
742 | A chunk that's in use looks like: |
743 | 743 | ||
744 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
744 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
745 | | Size of previous chunk (if P = 0) | |
745 | | Size of previous chunk (if P = 0) | |
746 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
746 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
747 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| |
747 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| |
748 | | Size of this chunk 1| +-+ |
748 | | Size of this chunk 1| +-+ |
749 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
749 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
750 | | | |
750 | | | |
751 | +- -+ |
751 | +- -+ |
752 | | | |
752 | | | |
753 | +- -+ |
753 | +- -+ |
754 | | : |
754 | | : |
755 | +- size - sizeof(size_t) available payload bytes -+ |
755 | +- size - sizeof(size_t) available payload bytes -+ |
756 | : | |
756 | : | |
757 | chunk-> +- -+ |
757 | chunk-> +- -+ |
758 | | | |
758 | | | |
759 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
759 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
760 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1| |
760 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1| |
761 | | Size of next chunk (may or may not be in use) | +-+ |
761 | | Size of next chunk (may or may not be in use) | +-+ |
762 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
762 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
763 | 763 | ||
764 | And if it's free, it looks like this: |
764 | And if it's free, it looks like this: |
765 | 765 | ||
766 | chunk-> +- -+ |
766 | chunk-> +- -+ |
767 | | User payload (must be in use, or we would have merged!) | |
767 | | User payload (must be in use, or we would have merged!) | |
768 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
768 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
769 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| |
769 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| |
770 | | Size of this chunk 0| +-+ |
770 | | Size of this chunk 0| +-+ |
771 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
771 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
772 | | Next pointer | |
772 | | Next pointer | |
773 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
773 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
774 | | Prev pointer | |
774 | | Prev pointer | |
775 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
775 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
776 | | : |
776 | | : |
777 | +- size - sizeof(struct chunk) unused bytes -+ |
777 | +- size - sizeof(struct chunk) unused bytes -+ |
778 | : | |
778 | : | |
779 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
779 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
780 | | Size of this chunk | |
780 | | Size of this chunk | |
781 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
781 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
782 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| |
782 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| |
783 | | Size of next chunk (must be in use, or we would have merged)| +-+ |
783 | | Size of next chunk (must be in use, or we would have merged)| +-+ |
784 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
784 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
785 | | : |
785 | | : |
786 | +- User payload -+ |
786 | +- User payload -+ |
787 | : | |
787 | : | |
788 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
788 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
789 | |0| |
789 | |0| |
790 | +-+ |
790 | +-+ |
791 | Note that since we always merge adjacent free chunks, the chunks |
791 | Note that since we always merge adjacent free chunks, the chunks |
792 | adjacent to a free chunk must be in use. |
792 | adjacent to a free chunk must be in use. |
793 | 793 | ||
794 | Given a pointer to a chunk (which can be derived trivially from the |
794 | Given a pointer to a chunk (which can be derived trivially from the |
795 | payload pointer) we can, in O(1) time, find out whether the adjacent |
795 | payload pointer) we can, in O(1) time, find out whether the adjacent |
796 | chunks are free, and if so, unlink them from the lists that they |
796 | chunks are free, and if so, unlink them from the lists that they |
797 | are on and merge them with the current chunk. |
797 | are on and merge them with the current chunk. |
798 | 798 | ||
799 | Chunks always begin on even word boundaries, so the mem portion |
799 | Chunks always begin on even word boundaries, so the mem portion |
800 | (which is returned to the user) is also on an even word boundary, and |
800 | (which is returned to the user) is also on an even word boundary, and |
801 | thus at least double-word aligned. |
801 | thus at least double-word aligned. |
802 | 802 | ||
803 | The P (PINUSE_BIT) bit, stored in the unused low-order bit of the |
803 | The P (PINUSE_BIT) bit, stored in the unused low-order bit of the |
804 | chunk size (which is always a multiple of two words), is an in-use |
804 | chunk size (which is always a multiple of two words), is an in-use |
805 | bit for the *previous* chunk. If that bit is *clear*, then the |
805 | bit for the *previous* chunk. If that bit is *clear*, then the |
806 | word before the current chunk size contains the previous chunk |
806 | word before the current chunk size contains the previous chunk |
807 | size, and can be used to find the front of the previous chunk. |
807 | size, and can be used to find the front of the previous chunk. |
808 | The very first chunk allocated always has this bit set, preventing |
808 | The very first chunk allocated always has this bit set, preventing |
809 | access to non-existent (or non-owned) memory. If pinuse is set for |
809 | access to non-existent (or non-owned) memory. If pinuse is set for |
810 | any given chunk, then you CANNOT determine the size of the |
810 | any given chunk, then you CANNOT determine the size of the |
811 | previous chunk, and might even get a memory addressing fault when |
811 | previous chunk, and might even get a memory addressing fault when |
812 | trying to do so. |
812 | trying to do so. |
813 | 813 | ||
814 | The C (CINUSE_BIT) bit, stored in the unused second-lowest bit of |
814 | The C (CINUSE_BIT) bit, stored in the unused second-lowest bit of |
815 | the chunk size redundantly records whether the current chunk is |
815 | the chunk size redundantly records whether the current chunk is |
816 | inuse (unless the chunk is mmapped). This redundancy enables usage |
816 | inuse (unless the chunk is mmapped). This redundancy enables usage |
817 | checks within free and realloc, and reduces indirection when freeing |
817 | checks within free and realloc, and reduces indirection when freeing |
818 | and consolidating chunks. |
818 | and consolidating chunks. |
819 | 819 | ||
820 | Each freshly allocated chunk must have both cinuse and pinuse set. |
820 | Each freshly allocated chunk must have both cinuse and pinuse set. |
821 | That is, each allocated chunk borders either a previously allocated |
821 | That is, each allocated chunk borders either a previously allocated |
822 | and still in-use chunk, or the base of its memory arena. This is |
822 | and still in-use chunk, or the base of its memory arena. This is |
823 | ensured by making all allocations from the `lowest' part of any |
823 | ensured by making all allocations from the `lowest' part of any |
824 | found chunk. Further, no free chunk physically borders another one, |
824 | found chunk. Further, no free chunk physically borders another one, |
825 | so each free chunk is known to be preceded and followed by either |
825 | so each free chunk is known to be preceded and followed by either |
826 | inuse chunks or the ends of memory. |
826 | inuse chunks or the ends of memory. |
827 | 827 | ||
828 | Note that the `foot' of the current chunk is actually represented |
828 | Note that the `foot' of the current chunk is actually represented |
829 | as the prev_foot of the NEXT chunk. This makes it easier to |
829 | as the prev_foot of the NEXT chunk. This makes it easier to |
830 | deal with alignments etc but can be very confusing when trying |
830 | deal with alignments etc but can be very confusing when trying |
831 | to extend or adapt this code. |
831 | to extend or adapt this code. |
832 | 832 | ||
833 | The exceptions to all this are |
833 | The exceptions to all this are |
834 | 834 | ||
835 | 1. The special chunk `top' is the top-most available chunk (i.e., |
835 | 1. The special chunk `top' is the top-most available chunk (i.e., |
836 | the one bordering the end of available memory). It is treated |
836 | the one bordering the end of available memory). It is treated |
837 | specially. Top is never included in any bin, is used only if |
837 | specially. Top is never included in any bin, is used only if |
838 | no other chunk is available, and is released back to the |
838 | no other chunk is available, and is released back to the |
839 | system if it is very large (see M_TRIM_THRESHOLD). In effect, |
839 | system if it is very large (see M_TRIM_THRESHOLD). In effect, |
840 | the top chunk is treated as larger (and thus less well |
840 | the top chunk is treated as larger (and thus less well |
841 | fitting) than any other available chunk. The top chunk |
841 | fitting) than any other available chunk. The top chunk |
842 | doesn't update its trailing size field since there is no next |
842 | doesn't update its trailing size field since there is no next |
843 | contiguous chunk that would have to index off it. However, |
843 | contiguous chunk that would have to index off it. However, |
844 | space is still allocated for it (TOP_FOOT_SIZE) to enable |
844 | space is still allocated for it (TOP_FOOT_SIZE) to enable |
845 | separation or merging when space is extended. |
845 | separation or merging when space is extended. |
846 | 846 | ||
847 | 3. Chunks allocated via mmap, have both cinuse and pinuse bits |
847 | 3. Chunks allocated via mmap, have both cinuse and pinuse bits |
848 | cleared in their head fields. Because they are allocated |
848 | cleared in their head fields. Because they are allocated |
849 | one-by-one, each must carry its own prev_foot field, which is |
849 | one-by-one, each must carry its own prev_foot field, which is |
850 | also used to hold the offset this chunk has within its mmapped |
850 | also used to hold the offset this chunk has within its mmapped |
851 | region, which is needed to preserve alignment. Each mmapped |
851 | region, which is needed to preserve alignment. Each mmapped |
852 | chunk is trailed by the first two fields of a fake next-chunk |
852 | chunk is trailed by the first two fields of a fake next-chunk |
853 | for sake of usage checks. |
853 | for sake of usage checks. |
854 | 854 | ||
855 | */ |
855 | */ |
856 | 856 | ||
857 | struct malloc_chunk { |
857 | struct malloc_chunk { |
858 | size_t prev_foot; /* Size of previous chunk (if free). */ |
858 | size_t prev_foot; /* Size of previous chunk (if free). */ |
859 | size_t head; /* Size and inuse bits. */ |
859 | size_t head; /* Size and inuse bits. */ |
860 | struct malloc_chunk* fd; /* double links -- used only if free. */ |
860 | struct malloc_chunk* fd; /* double links -- used only if free. */ |
861 | struct malloc_chunk* bk; |
861 | struct malloc_chunk* bk; |
862 | }; |
862 | }; |
863 | 863 | ||
864 | typedef struct malloc_chunk mchunk; |
864 | typedef struct malloc_chunk mchunk; |
865 | typedef struct malloc_chunk* mchunkptr; |
865 | typedef struct malloc_chunk* mchunkptr; |
866 | typedef struct malloc_chunk* sbinptr; /* The type of bins of chunks */ |
866 | typedef struct malloc_chunk* sbinptr; /* The type of bins of chunks */ |
867 | typedef unsigned int bindex_t; /* Described below */ |
867 | typedef unsigned int bindex_t; /* Described below */ |
868 | typedef unsigned int binmap_t; /* Described below */ |
868 | typedef unsigned int binmap_t; /* Described below */ |
869 | typedef unsigned int flag_t; /* The type of various bit flag sets */ |
869 | typedef unsigned int flag_t; /* The type of various bit flag sets */ |
870 | 870 | ||
871 | /* ------------------- Chunks sizes and alignments ----------------------- */ |
871 | /* ------------------- Chunks sizes and alignments ----------------------- */ |
872 | 872 | ||
873 | #define MCHUNK_SIZE (sizeof(mchunk)) |
873 | #define MCHUNK_SIZE (sizeof(mchunk)) |
874 | 874 | ||
875 | #if FOOTERS |
875 | #if FOOTERS |
876 | #define CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) |
876 | #define CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) |
877 | #else /* FOOTERS */ |
877 | #else /* FOOTERS */ |
878 | #define CHUNK_OVERHEAD (SIZE_T_SIZE) |
878 | #define CHUNK_OVERHEAD (SIZE_T_SIZE) |
879 | #endif /* FOOTERS */ |
879 | #endif /* FOOTERS */ |
880 | 880 | ||
881 | /* MMapped chunks need a second word of overhead ... */ |
881 | /* MMapped chunks need a second word of overhead ... */ |
882 | #define MMAP_CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) |
882 | #define MMAP_CHUNK_OVERHEAD (TWO_SIZE_T_SIZES) |
883 | /* ... and additional padding for fake next-chunk at foot */ |
883 | /* ... and additional padding for fake next-chunk at foot */ |
884 | #define MMAP_FOOT_PAD (FOUR_SIZE_T_SIZES) |
884 | #define MMAP_FOOT_PAD (FOUR_SIZE_T_SIZES) |
885 | 885 | ||
886 | /* The smallest size we can malloc is an aligned minimal chunk */ |
886 | /* The smallest size we can malloc is an aligned minimal chunk */ |
887 | #define MIN_CHUNK_SIZE\ |
887 | #define MIN_CHUNK_SIZE\ |
888 | ((MCHUNK_SIZE + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) |
888 | ((MCHUNK_SIZE + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) |
889 | 889 | ||
890 | /* conversion from malloc headers to user pointers, and back */ |
890 | /* conversion from malloc headers to user pointers, and back */ |
891 | #define chunk2mem(p) ((void*)((char*)(p) + TWO_SIZE_T_SIZES)) |
891 | #define chunk2mem(p) ((void*)((char*)(p) + TWO_SIZE_T_SIZES)) |
892 | #define mem2chunk(mem) ((mchunkptr)((char*)(mem) - TWO_SIZE_T_SIZES)) |
892 | #define mem2chunk(mem) ((mchunkptr)((char*)(mem) - TWO_SIZE_T_SIZES)) |
893 | /* chunk associated with aligned address A */ |
893 | /* chunk associated with aligned address A */ |
894 | #define align_as_chunk(A) (mchunkptr)((A) + align_offset(chunk2mem(A))) |
894 | #define align_as_chunk(A) (mchunkptr)((A) + align_offset(chunk2mem(A))) |
895 | 895 | ||
896 | /* Bounds on request (not chunk) sizes. */ |
896 | /* Bounds on request (not chunk) sizes. */ |
897 | #define MAX_REQUEST ((-MIN_CHUNK_SIZE) << 2) |
897 | #define MAX_REQUEST ((-MIN_CHUNK_SIZE) << 2) |
898 | #define MIN_REQUEST (MIN_CHUNK_SIZE - CHUNK_OVERHEAD - SIZE_T_ONE) |
898 | #define MIN_REQUEST (MIN_CHUNK_SIZE - CHUNK_OVERHEAD - SIZE_T_ONE) |
899 | 899 | ||
900 | /* pad request bytes into a usable size */ |
900 | /* pad request bytes into a usable size */ |
901 | #define pad_request(req) \ |
901 | #define pad_request(req) \ |
902 | (((req) + CHUNK_OVERHEAD + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) |
902 | (((req) + CHUNK_OVERHEAD + CHUNK_ALIGN_MASK) & ~CHUNK_ALIGN_MASK) |
903 | 903 | ||
904 | /* pad request, checking for minimum (but not maximum) */ |
904 | /* pad request, checking for minimum (but not maximum) */ |
905 | #define request2size(req) \ |
905 | #define request2size(req) \ |
906 | (((req) < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(req)) |
906 | (((req) < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(req)) |
907 | 907 | ||
908 | 908 | ||
909 | /* ------------------ Operations on head and foot fields ----------------- */ |
909 | /* ------------------ Operations on head and foot fields ----------------- */ |
910 | 910 | ||
911 | /* |
911 | /* |
912 | The head field of a chunk is or'ed with PINUSE_BIT when previous |
912 | The head field of a chunk is or'ed with PINUSE_BIT when previous |
913 | adjacent chunk in use, and or'ed with CINUSE_BIT if this chunk is in |
913 | adjacent chunk in use, and or'ed with CINUSE_BIT if this chunk is in |
914 | use, unless mmapped, in which case both bits are cleared. |
914 | use, unless mmapped, in which case both bits are cleared. |
915 | 915 | ||
916 | FLAG4_BIT is not used by this malloc, but might be useful in extensions. |
916 | FLAG4_BIT is not used by this malloc, but might be useful in extensions. |
917 | */ |
917 | */ |
918 | 918 | ||
919 | #define PINUSE_BIT (SIZE_T_ONE) |
919 | #define PINUSE_BIT (SIZE_T_ONE) |
920 | #define CINUSE_BIT (SIZE_T_TWO) |
920 | #define CINUSE_BIT (SIZE_T_TWO) |
921 | #define FLAG4_BIT (SIZE_T_FOUR) |
921 | #define FLAG4_BIT (SIZE_T_FOUR) |
922 | #define INUSE_BITS (PINUSE_BIT|CINUSE_BIT) |
922 | #define INUSE_BITS (PINUSE_BIT|CINUSE_BIT) |
923 | #define FLAG_BITS (PINUSE_BIT|CINUSE_BIT|FLAG4_BIT) |
923 | #define FLAG_BITS (PINUSE_BIT|CINUSE_BIT|FLAG4_BIT) |
924 | 924 | ||
925 | /* Head value for fenceposts */ |
925 | /* Head value for fenceposts */ |
926 | #define FENCEPOST_HEAD (INUSE_BITS|SIZE_T_SIZE) |
926 | #define FENCEPOST_HEAD (INUSE_BITS|SIZE_T_SIZE) |
927 | 927 | ||
928 | /* extraction of fields from head words */ |
928 | /* extraction of fields from head words */ |
929 | #define cinuse(p) ((p)->head & CINUSE_BIT) |
929 | #define cinuse(p) ((p)->head & CINUSE_BIT) |
930 | #define pinuse(p) ((p)->head & PINUSE_BIT) |
930 | #define pinuse(p) ((p)->head & PINUSE_BIT) |
931 | #define flag4inuse(p) ((p)->head & FLAG4_BIT) |
931 | #define flag4inuse(p) ((p)->head & FLAG4_BIT) |
932 | #define is_inuse(p) (((p)->head & INUSE_BITS) != PINUSE_BIT) |
932 | #define is_inuse(p) (((p)->head & INUSE_BITS) != PINUSE_BIT) |
933 | #define is_mmapped(p) (((p)->head & INUSE_BITS) == 0) |
933 | #define is_mmapped(p) (((p)->head & INUSE_BITS) == 0) |
934 | 934 | ||
935 | #define chunksize(p) ((p)->head & ~(FLAG_BITS)) |
935 | #define chunksize(p) ((p)->head & ~(FLAG_BITS)) |
936 | 936 | ||
937 | #define clear_pinuse(p) ((p)->head &= ~PINUSE_BIT) |
937 | #define clear_pinuse(p) ((p)->head &= ~PINUSE_BIT) |
938 | #define set_flag4(p) ((p)->head |= FLAG4_BIT) |
938 | #define set_flag4(p) ((p)->head |= FLAG4_BIT) |
939 | #define clear_flag4(p) ((p)->head &= ~FLAG4_BIT) |
939 | #define clear_flag4(p) ((p)->head &= ~FLAG4_BIT) |
940 | 940 | ||
941 | /* Treat space at ptr +/- offset as a chunk */ |
941 | /* Treat space at ptr +/- offset as a chunk */ |
942 | #define chunk_plus_offset(p, s) ((mchunkptr)(((char*)(p)) + (s))) |
942 | #define chunk_plus_offset(p, s) ((mchunkptr)(((char*)(p)) + (s))) |
943 | #define chunk_minus_offset(p, s) ((mchunkptr)(((char*)(p)) - (s))) |
943 | #define chunk_minus_offset(p, s) ((mchunkptr)(((char*)(p)) - (s))) |
944 | 944 | ||
945 | /* Ptr to next or previous physical malloc_chunk. */ |
945 | /* Ptr to next or previous physical malloc_chunk. */ |
946 | #define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->head & ~FLAG_BITS))) |
946 | #define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->head & ~FLAG_BITS))) |
947 | #define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_foot) )) |
947 | #define prev_chunk(p) ((mchunkptr)( ((char*)(p)) - ((p)->prev_foot) )) |
948 | 948 | ||
949 | /* extract next chunk's pinuse bit */ |
949 | /* extract next chunk's pinuse bit */ |
950 | #define next_pinuse(p) ((next_chunk(p)->head) & PINUSE_BIT) |
950 | #define next_pinuse(p) ((next_chunk(p)->head) & PINUSE_BIT) |
951 | 951 | ||
952 | /* Get/set size at footer */ |
952 | /* Get/set size at footer */ |
953 | #define get_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot) |
953 | #define get_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot) |
954 | #define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot = (s)) |
954 | #define set_foot(p, s) (((mchunkptr)((char*)(p) + (s)))->prev_foot = (s)) |
955 | 955 | ||
956 | /* Set size, pinuse bit, and foot */ |
956 | /* Set size, pinuse bit, and foot */ |
957 | #define set_size_and_pinuse_of_free_chunk(p, s)\ |
957 | #define set_size_and_pinuse_of_free_chunk(p, s)\ |
958 | ((p)->head = (s|PINUSE_BIT), set_foot(p, s)) |
958 | ((p)->head = (s|PINUSE_BIT), set_foot(p, s)) |
959 | 959 | ||
960 | /* Set size, pinuse bit, foot, and clear next pinuse */ |
960 | /* Set size, pinuse bit, foot, and clear next pinuse */ |
961 | #define set_free_with_pinuse(p, s, n)\ |
961 | #define set_free_with_pinuse(p, s, n)\ |
962 | (clear_pinuse(n), set_size_and_pinuse_of_free_chunk(p, s)) |
962 | (clear_pinuse(n), set_size_and_pinuse_of_free_chunk(p, s)) |
963 | 963 | ||
964 | /* Get the internal overhead associated with chunk p */ |
964 | /* Get the internal overhead associated with chunk p */ |
965 | #define overhead_for(p)\ |
965 | #define overhead_for(p)\ |
966 | (is_mmapped(p)? MMAP_CHUNK_OVERHEAD : CHUNK_OVERHEAD) |
966 | (is_mmapped(p)? MMAP_CHUNK_OVERHEAD : CHUNK_OVERHEAD) |
967 | 967 | ||
968 | /* Return true if malloced space is not necessarily cleared */ |
968 | /* Return true if malloced space is not necessarily cleared */ |
969 | #if MMAP_CLEARS |
969 | #if MMAP_CLEARS |
970 | #define calloc_must_clear(p) (!is_mmapped(p)) |
970 | #define calloc_must_clear(p) (!is_mmapped(p)) |
971 | #else /* MMAP_CLEARS */ |
971 | #else /* MMAP_CLEARS */ |
972 | #define calloc_must_clear(p) (1) |
972 | #define calloc_must_clear(p) (1) |
973 | #endif /* MMAP_CLEARS */ |
973 | #endif /* MMAP_CLEARS */ |
974 | 974 | ||
975 | /* ---------------------- Overlaid data structures ----------------------- */ |
975 | /* ---------------------- Overlaid data structures ----------------------- */ |
976 | 976 | ||
977 | /* |
977 | /* |
978 | When chunks are not in use, they are treated as nodes of either |
978 | When chunks are not in use, they are treated as nodes of either |
979 | lists or trees. |
979 | lists or trees. |
980 | 980 | ||
981 | "Small" chunks are stored in circular doubly-linked lists, and look |
981 | "Small" chunks are stored in circular doubly-linked lists, and look |
982 | like this: |
982 | like this: |
983 | 983 | ||
984 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
984 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
985 | | Size of previous chunk | |
985 | | Size of previous chunk | |
986 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
986 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
987 | `head:' | Size of chunk, in bytes |P| |
987 | `head:' | Size of chunk, in bytes |P| |
988 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
988 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
989 | | Forward pointer to next chunk in list | |
989 | | Forward pointer to next chunk in list | |
990 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
990 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
991 | | Back pointer to previous chunk in list | |
991 | | Back pointer to previous chunk in list | |
992 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
992 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
993 | | Unused space (may be 0 bytes long) . |
993 | | Unused space (may be 0 bytes long) . |
994 | . . |
994 | . . |
995 | . | |
995 | . | |
996 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
996 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
997 | `foot:' | Size of chunk, in bytes | |
997 | `foot:' | Size of chunk, in bytes | |
998 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
998 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
999 | 999 | ||
1000 | Larger chunks are kept in a form of bitwise digital trees (aka |
1000 | Larger chunks are kept in a form of bitwise digital trees (aka |
1001 | tries) keyed on chunksizes. Because malloc_tree_chunks are only for |
1001 | tries) keyed on chunksizes. Because malloc_tree_chunks are only for |
1002 | free chunks greater than 256 bytes, their size doesn't impose any |
1002 | free chunks greater than 256 bytes, their size doesn't impose any |
1003 | constraints on user chunk sizes. Each node looks like: |
1003 | constraints on user chunk sizes. Each node looks like: |
1004 | 1004 | ||
1005 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1005 | chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1006 | | Size of previous chunk | |
1006 | | Size of previous chunk | |
1007 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1007 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1008 | `head:' | Size of chunk, in bytes |P| |
1008 | `head:' | Size of chunk, in bytes |P| |
1009 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1009 | mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1010 | | Forward pointer to next chunk of same size | |
1010 | | Forward pointer to next chunk of same size | |
1011 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1011 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1012 | | Back pointer to previous chunk of same size | |
1012 | | Back pointer to previous chunk of same size | |
1013 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1013 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1014 | | Pointer to left child (child[0]) | |
1014 | | Pointer to left child (child[0]) | |
1015 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1015 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1016 | | Pointer to right child (child[1]) | |
1016 | | Pointer to right child (child[1]) | |
1017 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1017 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1018 | | Pointer to parent | |
1018 | | Pointer to parent | |
1019 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1019 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1020 | | bin index of this chunk | |
1020 | | bin index of this chunk | |
1021 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1021 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1022 | | Unused space . |
1022 | | Unused space . |
1023 | . | |
1023 | . | |
1024 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1024 | nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1025 | `foot:' | Size of chunk, in bytes | |
1025 | `foot:' | Size of chunk, in bytes | |
1026 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1026 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
1027 | 1027 | ||
1028 | Each tree holding treenodes is a tree of unique chunk sizes. Chunks |
1028 | Each tree holding treenodes is a tree of unique chunk sizes. Chunks |
1029 | of the same size are arranged in a circularly-linked list, with only |
1029 | of the same size are arranged in a circularly-linked list, with only |
1030 | the oldest chunk (the next to be used, in our FIFO ordering) |
1030 | the oldest chunk (the next to be used, in our FIFO ordering) |
1031 | actually in the tree. (Tree members are distinguished by a non-null |
1031 | actually in the tree. (Tree members are distinguished by a non-null |
1032 | parent pointer.) If a chunk with the same size an an existing node |
1032 | parent pointer.) If a chunk with the same size an an existing node |
1033 | is inserted, it is linked off the existing node using pointers that |
1033 | is inserted, it is linked off the existing node using pointers that |
1034 | work in the same way as fd/bk pointers of small chunks. |
1034 | work in the same way as fd/bk pointers of small chunks. |
1035 | 1035 | ||
1036 | Each tree contains a power of 2 sized range of chunk sizes (the |
1036 | Each tree contains a power of 2 sized range of chunk sizes (the |
1037 | smallest is 0x100 <= x < 0x180), which is is divided in half at each |
1037 | smallest is 0x100 <= x < 0x180), which is is divided in half at each |
1038 | tree level, with the chunks in the smaller half of the range (0x100 |
1038 | tree level, with the chunks in the smaller half of the range (0x100 |
1039 | <= x < 0x140 for the top nose) in the left subtree and the larger |
1039 | <= x < 0x140 for the top nose) in the left subtree and the larger |
1040 | half (0x140 <= x < 0x180) in the right subtree. This is, of course, |
1040 | half (0x140 <= x < 0x180) in the right subtree. This is, of course, |
1041 | done by inspecting individual bits. |
1041 | done by inspecting individual bits. |
1042 | 1042 | ||
1043 | Using these rules, each node's left subtree contains all smaller |
1043 | Using these rules, each node's left subtree contains all smaller |
1044 | sizes than its right subtree. However, the node at the root of each |
1044 | sizes than its right subtree. However, the node at the root of each |
1045 | subtree has no particular ordering relationship to either. (The |
1045 | subtree has no particular ordering relationship to either. (The |
1046 | dividing line between the subtree sizes is based on trie relation.) |
1046 | dividing line between the subtree sizes is based on trie relation.) |
1047 | If we remove the last chunk of a given size from the interior of the |
1047 | If we remove the last chunk of a given size from the interior of the |
1048 | tree, we need to replace it with a leaf node. The tree ordering |
1048 | tree, we need to replace it with a leaf node. The tree ordering |
1049 | rules permit a node to be replaced by any leaf below it. |
1049 | rules permit a node to be replaced by any leaf below it. |
1050 | 1050 | ||
1051 | The smallest chunk in a tree (a common operation in a best-fit |
1051 | The smallest chunk in a tree (a common operation in a best-fit |
1052 | allocator) can be found by walking a path to the leftmost leaf in |
1052 | allocator) can be found by walking a path to the leftmost leaf in |
1053 | the tree. Unlike a usual binary tree, where we follow left child |
1053 | the tree. Unlike a usual binary tree, where we follow left child |
1054 | pointers until we reach a null, here we follow the right child |
1054 | pointers until we reach a null, here we follow the right child |
1055 | pointer any time the left one is null, until we reach a leaf with |
1055 | pointer any time the left one is null, until we reach a leaf with |
1056 | both child pointers null. The smallest chunk in the tree will be |
1056 | both child pointers null. The smallest chunk in the tree will be |
1057 | somewhere along that path. |
1057 | somewhere along that path. |
1058 | 1058 | ||
1059 | The worst case number of steps to add, find, or remove a node is |
1059 | The worst case number of steps to add, find, or remove a node is |
1060 | bounded by the number of bits differentiating chunks within |
1060 | bounded by the number of bits differentiating chunks within |
1061 | bins. Under current bin calculations, this ranges from 6 up to 21 |
1061 | bins. Under current bin calculations, this ranges from 6 up to 21 |
1062 | (for 32 bit sizes) or up to 53 (for 64 bit sizes). The typical case |
1062 | (for 32 bit sizes) or up to 53 (for 64 bit sizes). The typical case |
1063 | is of course much better. |
1063 | is of course much better. |
1064 | */ |
1064 | */ |
1065 | 1065 | ||
1066 | struct malloc_tree_chunk { |
1066 | struct malloc_tree_chunk { |
1067 | /* The first four fields must be compatible with malloc_chunk */ |
1067 | /* The first four fields must be compatible with malloc_chunk */ |
1068 | size_t prev_foot; |
1068 | size_t prev_foot; |
1069 | size_t head; |
1069 | size_t head; |
1070 | struct malloc_tree_chunk* fd; |
1070 | struct malloc_tree_chunk* fd; |
1071 | struct malloc_tree_chunk* bk; |
1071 | struct malloc_tree_chunk* bk; |
1072 | 1072 | ||
1073 | struct malloc_tree_chunk* child[2]; |
1073 | struct malloc_tree_chunk* child[2]; |
1074 | struct malloc_tree_chunk* parent; |
1074 | struct malloc_tree_chunk* parent; |
1075 | bindex_t index; |
1075 | bindex_t index; |
1076 | }; |
1076 | }; |
1077 | 1077 | ||
1078 | typedef struct malloc_tree_chunk tchunk; |
1078 | typedef struct malloc_tree_chunk tchunk; |
1079 | typedef struct malloc_tree_chunk* tchunkptr; |
1079 | typedef struct malloc_tree_chunk* tchunkptr; |
1080 | typedef struct malloc_tree_chunk* tbinptr; /* The type of bins of trees */ |
1080 | typedef struct malloc_tree_chunk* tbinptr; /* The type of bins of trees */ |
1081 | 1081 | ||
1082 | /* A little helper macro for trees */ |
1082 | /* A little helper macro for trees */ |
1083 | #define leftmost_child(t) ((t)->child[0] != 0? (t)->child[0] : (t)->child[1]) |
1083 | #define leftmost_child(t) ((t)->child[0] != 0? (t)->child[0] : (t)->child[1]) |
1084 | 1084 | ||
1085 | /* ----------------------------- Segments -------------------------------- */ |
1085 | /* ----------------------------- Segments -------------------------------- */ |
1086 | 1086 | ||
1087 | /* |
1087 | /* |
1088 | Each malloc space may include non-contiguous segments, held in a |
1088 | Each malloc space may include non-contiguous segments, held in a |
1089 | list headed by an embedded malloc_segment record representing the |
1089 | list headed by an embedded malloc_segment record representing the |
1090 | top-most space. Segments also include flags holding properties of |
1090 | top-most space. Segments also include flags holding properties of |
1091 | the space. Large chunks that are directly allocated by mmap are not |
1091 | the space. Large chunks that are directly allocated by mmap are not |
1092 | included in this list. They are instead independently created and |
1092 | included in this list. They are instead independently created and |
1093 | destroyed without otherwise keeping track of them. |
1093 | destroyed without otherwise keeping track of them. |
1094 | 1094 | ||
1095 | Segment management mainly comes into play for spaces allocated by |
1095 | Segment management mainly comes into play for spaces allocated by |
1096 | MMAP. Any call to MMAP might or might not return memory that is |
1096 | MMAP. Any call to MMAP might or might not return memory that is |
1097 | adjacent to an existing segment. MORECORE normally contiguously |
1097 | adjacent to an existing segment. MORECORE normally contiguously |
1098 | extends the current space, so this space is almost always adjacent, |
1098 | extends the current space, so this space is almost always adjacent, |
1099 | which is simpler and faster to deal with. (This is why MORECORE is |
1099 | which is simpler and faster to deal with. (This is why MORECORE is |
1100 | used preferentially to MMAP when both are available -- see |
1100 | used preferentially to MMAP when both are available -- see |
1101 | sys_alloc.) When allocating using MMAP, we don't use any of the |
1101 | sys_alloc.) When allocating using MMAP, we don't use any of the |
1102 | hinting mechanisms (inconsistently) supported in various |
1102 | hinting mechanisms (inconsistently) supported in various |
1103 | implementations of unix mmap, or distinguish reserving from |
1103 | implementations of unix mmap, or distinguish reserving from |
1104 | committing memory. Instead, we just ask for space, and exploit |
1104 | committing memory. Instead, we just ask for space, and exploit |
1105 | contiguity when we get it. It is probably possible to do |
1105 | contiguity when we get it. It is probably possible to do |
1106 | better than this on some systems, but no general scheme seems |
1106 | better than this on some systems, but no general scheme seems |
1107 | to be significantly better. |
1107 | to be significantly better. |
1108 | 1108 | ||
1109 | Management entails a simpler variant of the consolidation scheme |
1109 | Management entails a simpler variant of the consolidation scheme |
1110 | used for chunks to reduce fragmentation -- new adjacent memory is |
1110 | used for chunks to reduce fragmentation -- new adjacent memory is |
1111 | normally prepended or appended to an existing segment. However, |
1111 | normally prepended or appended to an existing segment. However, |
1112 | there are limitations compared to chunk consolidation that mostly |
1112 | there are limitations compared to chunk consolidation that mostly |
1113 | reflect the fact that segment processing is relatively infrequent |
1113 | reflect the fact that segment processing is relatively infrequent |
1114 | (occurring only when getting memory from system) and that we |
1114 | (occurring only when getting memory from system) and that we |
1115 | don't expect to have huge numbers of segments: |
1115 | don't expect to have huge numbers of segments: |
1116 | 1116 | ||
1117 | * Segments are not indexed, so traversal requires linear scans. (It |
1117 | * Segments are not indexed, so traversal requires linear scans. (It |
1118 | would be possible to index these, but is not worth the extra |
1118 | would be possible to index these, but is not worth the extra |
1119 | overhead and complexity for most programs on most platforms.) |
1119 | overhead and complexity for most programs on most platforms.) |
1120 | * New segments are only appended to old ones when holding top-most |
1120 | * New segments are only appended to old ones when holding top-most |
1121 | memory; if they cannot be prepended to others, they are held in |
1121 | memory; if they cannot be prepended to others, they are held in |
1122 | different segments. |
1122 | different segments. |
1123 | 1123 | ||
1124 | Except for the top-most segment of an mstate, each segment record |
1124 | Except for the top-most segment of an mstate, each segment record |
1125 | is kept at the tail of its segment. Segments are added by pushing |
1125 | is kept at the tail of its segment. Segments are added by pushing |
1126 | segment records onto the list headed by &mstate.seg for the |
1126 | segment records onto the list headed by &mstate.seg for the |
1127 | containing mstate. |
1127 | containing mstate. |
1128 | 1128 | ||
1129 | Segment flags control allocation/merge/deallocation policies: |
1129 | Segment flags control allocation/merge/deallocation policies: |
1130 | * If EXTERN_BIT set, then we did not allocate this segment, |
1130 | * If EXTERN_BIT set, then we did not allocate this segment, |
1131 | and so should not try to deallocate or merge with others. |
1131 | and so should not try to deallocate or merge with others. |
1132 | (This currently holds only for the initial segment passed |
1132 | (This currently holds only for the initial segment passed |
1133 | into create_mspace_with_base.) |
1133 | into create_mspace_with_base.) |
1134 | * If USE_MMAP_BIT set, the segment may be merged with |
1134 | * If USE_MMAP_BIT set, the segment may be merged with |
1135 | other surrounding mmapped segments and trimmed/de-allocated |
1135 | other surrounding mmapped segments and trimmed/de-allocated |
1136 | using munmap. |
1136 | using munmap. |
1137 | * If neither bit is set, then the segment was obtained using |
1137 | * If neither bit is set, then the segment was obtained using |
1138 | MORECORE so can be merged with surrounding MORECORE'd segments |
1138 | MORECORE so can be merged with surrounding MORECORE'd segments |
1139 | and deallocated/trimmed using MORECORE with negative arguments. |
1139 | and deallocated/trimmed using MORECORE with negative arguments. |
1140 | */ |
1140 | */ |
1141 | 1141 | ||
1142 | struct malloc_segment { |
1142 | struct malloc_segment { |
1143 | char* base; /* base address */ |
1143 | char* base; /* base address */ |
1144 | size_t size; /* allocated size */ |
1144 | size_t size; /* allocated size */ |
1145 | struct malloc_segment* next; /* ptr to next segment */ |
1145 | struct malloc_segment* next; /* ptr to next segment */ |
1146 | flag_t sflags; /* mmap and extern flag */ |
1146 | flag_t sflags; /* mmap and extern flag */ |
1147 | }; |
1147 | }; |
1148 | 1148 | ||
1149 | #define is_mmapped_segment(S) ((S)->sflags & USE_MMAP_BIT) |
1149 | #define is_mmapped_segment(S) ((S)->sflags & USE_MMAP_BIT) |
1150 | #define is_extern_segment(S) ((S)->sflags & EXTERN_BIT) |
1150 | #define is_extern_segment(S) ((S)->sflags & EXTERN_BIT) |
1151 | 1151 | ||
1152 | typedef struct malloc_segment msegment; |
1152 | typedef struct malloc_segment msegment; |
1153 | typedef struct malloc_segment* msegmentptr; |
1153 | typedef struct malloc_segment* msegmentptr; |
1154 | 1154 | ||
1155 | /* ---------------------------- malloc_state ----------------------------- */ |
1155 | /* ---------------------------- malloc_state ----------------------------- */ |
1156 | 1156 | ||
1157 | /* |
1157 | /* |
1158 | A malloc_state holds all of the bookkeeping for a space. |
1158 | A malloc_state holds all of the bookkeeping for a space. |
1159 | The main fields are: |
1159 | The main fields are: |
1160 | 1160 | ||
1161 | Top |
1161 | Top |
1162 | The topmost chunk of the currently active segment. Its size is |
1162 | The topmost chunk of the currently active segment. Its size is |
1163 | cached in topsize. The actual size of topmost space is |
1163 | cached in topsize. The actual size of topmost space is |
1164 | topsize+TOP_FOOT_SIZE, which includes space reserved for adding |
1164 | topsize+TOP_FOOT_SIZE, which includes space reserved for adding |
1165 | fenceposts and segment records if necessary when getting more |
1165 | fenceposts and segment records if necessary when getting more |
1166 | space from the system. The size at which to autotrim top is |
1166 | space from the system. The size at which to autotrim top is |
1167 | cached from mparams in trim_check, except that it is disabled if |
1167 | cached from mparams in trim_check, except that it is disabled if |
1168 | an autotrim fails. |
1168 | an autotrim fails. |
1169 | 1169 | ||
1170 | Designated victim (dv) |
1170 | Designated victim (dv) |
1171 | This is the preferred chunk for servicing small requests that |
1171 | This is the preferred chunk for servicing small requests that |
1172 | don't have exact fits. It is normally the chunk split off most |
1172 | don't have exact fits. It is normally the chunk split off most |
1173 | recently to service another small request. Its size is cached in |
1173 | recently to service another small request. Its size is cached in |
1174 | dvsize. The link fields of this chunk are not maintained since it |
1174 | dvsize. The link fields of this chunk are not maintained since it |
1175 | is not kept in a bin. |
1175 | is not kept in a bin. |
1176 | 1176 | ||
1177 | SmallBins |
1177 | SmallBins |
1178 | An array of bin headers for free chunks. These bins hold chunks |
1178 | An array of bin headers for free chunks. These bins hold chunks |
1179 | with sizes less than MIN_LARGE_SIZE bytes. Each bin contains |
1179 | with sizes less than MIN_LARGE_SIZE bytes. Each bin contains |
1180 | chunks of all the same size, spaced 8 bytes apart. To simplify |
1180 | chunks of all the same size, spaced 8 bytes apart. To simplify |
1181 | use in double-linked lists, each bin header acts as a malloc_chunk |
1181 | use in double-linked lists, each bin header acts as a malloc_chunk |
1182 | pointing to the real first node, if it exists (else pointing to |
1182 | pointing to the real first node, if it exists (else pointing to |
1183 | itself). This avoids special-casing for headers. But to avoid |
1183 | itself). This avoids special-casing for headers. But to avoid |
1184 | waste, we allocate only the fd/bk pointers of bins, and then use |
1184 | waste, we allocate only the fd/bk pointers of bins, and then use |
1185 | repositioning tricks to treat these as the fields of a chunk. |
1185 | repositioning tricks to treat these as the fields of a chunk. |
1186 | 1186 | ||
1187 | TreeBins |
1187 | TreeBins |
1188 | Treebins are pointers to the roots of trees holding a range of |
1188 | Treebins are pointers to the roots of trees holding a range of |
1189 | sizes. There are 2 equally spaced treebins for each power of two |
1189 | sizes. There are 2 equally spaced treebins for each power of two |
1190 | from TREE_SHIFT to TREE_SHIFT+16. The last bin holds anything |
1190 | from TREE_SHIFT to TREE_SHIFT+16. The last bin holds anything |
1191 | larger. |
1191 | larger. |
1192 | 1192 | ||
1193 | Bin maps |
1193 | Bin maps |
1194 | There is one bit map for small bins ("smallmap") and one for |
1194 | There is one bit map for small bins ("smallmap") and one for |
1195 | treebins ("treemap). Each bin sets its bit when non-empty, and |
1195 | treebins ("treemap). Each bin sets its bit when non-empty, and |
1196 | clears the bit when empty. Bit operations are then used to avoid |
1196 | clears the bit when empty. Bit operations are then used to avoid |
1197 | bin-by-bin searching -- nearly all "search" is done without ever |
1197 | bin-by-bin searching -- nearly all "search" is done without ever |
1198 | looking at bins that won't be selected. The bit maps |
1198 | looking at bins that won't be selected. The bit maps |
1199 | conservatively use 32 bits per map word, even if on 64bit system. |
1199 | conservatively use 32 bits per map word, even if on 64bit system. |
1200 | For a good description of some of the bit-based techniques used |
1200 | For a good description of some of the bit-based techniques used |
1201 | here, see Henry S. Warren Jr's book "Hacker's Delight" (and |
1201 | here, see Henry S. Warren Jr's book "Hacker's Delight" (and |
1202 | supplement at http://hackersdelight.org/). Many of these are |
1202 | supplement at http://hackersdelight.org/). Many of these are |
1203 | intended to reduce the branchiness of paths through malloc etc, as |
1203 | intended to reduce the branchiness of paths through malloc etc, as |
1204 | well as to reduce the number of memory locations read or written. |
1204 | well as to reduce the number of memory locations read or written. |
1205 | 1205 | ||
1206 | Segments |
1206 | Segments |
1207 | A list of segments headed by an embedded malloc_segment record |
1207 | A list of segments headed by an embedded malloc_segment record |
1208 | representing the initial space. |
1208 | representing the initial space. |
1209 | 1209 | ||
1210 | Address check support |
1210 | Address check support |
1211 | The least_addr field is the least address ever obtained from |
1211 | The least_addr field is the least address ever obtained from |
1212 | MORECORE or MMAP. Attempted frees and reallocs of any address less |
1212 | MORECORE or MMAP. Attempted frees and reallocs of any address less |
1213 | than this are trapped (unless INSECURE is defined). |
1213 | than this are trapped (unless INSECURE is defined). |
1214 | 1214 | ||
1215 | Magic tag |
1215 | Magic tag |
1216 | A cross-check field that should always hold same value as mparams.magic. |
1216 | A cross-check field that should always hold same value as mparams.magic. |
1217 | 1217 | ||
1218 | Max allowed footprint |
1218 | Max allowed footprint |
1219 | The maximum allowed bytes to allocate from system (zero means no limit) |
1219 | The maximum allowed bytes to allocate from system (zero means no limit) |
1220 | 1220 | ||
1221 | Flags |
1221 | Flags |
1222 | Bits recording whether to use MMAP, locks, or contiguous MORECORE |
1222 | Bits recording whether to use MMAP, locks, or contiguous MORECORE |
1223 | 1223 | ||
1224 | Statistics |
1224 | Statistics |
1225 | Each space keeps track of current and maximum system memory |
1225 | Each space keeps track of current and maximum system memory |
1226 | obtained via MORECORE or MMAP. |
1226 | obtained via MORECORE or MMAP. |
1227 | 1227 | ||
1228 | Trim support |
1228 | Trim support |
1229 | Fields holding the amount of unused topmost memory that should trigger |
1229 | Fields holding the amount of unused topmost memory that should trigger |
1230 | trimming, and a counter to force periodic scanning to release unused |
1230 | trimming, and a counter to force periodic scanning to release unused |
1231 | non-topmost segments. |
1231 | non-topmost segments. |
1232 | 1232 | ||
1233 | Locking |
1233 | Locking |
1234 | If USE_LOCKS is defined, the "mutex" lock is acquired and released |
1234 | If USE_LOCKS is defined, the "mutex" lock is acquired and released |
1235 | around every public call using this mspace. |
1235 | around every public call using this mspace. |
1236 | 1236 | ||
1237 | Extension support |
1237 | Extension support |
1238 | A void* pointer and a size_t field that can be used to help implement |
1238 | A void* pointer and a size_t field that can be used to help implement |
1239 | extensions to this malloc. |
1239 | extensions to this malloc. |
1240 | */ |
1240 | */ |
1241 | 1241 | ||
1242 | /* Bin types, widths and sizes */ |
1242 | /* Bin types, widths and sizes */ |
1243 | #define NSMALLBINS (32U) |
1243 | #define NSMALLBINS (32U) |
1244 | #define NTREEBINS (32U) |
1244 | #define NTREEBINS (32U) |
1245 | #define SMALLBIN_SHIFT (3U) |
1245 | #define SMALLBIN_SHIFT (3U) |
1246 | #define SMALLBIN_WIDTH (SIZE_T_ONE << SMALLBIN_SHIFT) |
1246 | #define SMALLBIN_WIDTH (SIZE_T_ONE << SMALLBIN_SHIFT) |
1247 | #define TREEBIN_SHIFT (8U) |
1247 | #define TREEBIN_SHIFT (8U) |
1248 | #define MIN_LARGE_SIZE (SIZE_T_ONE << TREEBIN_SHIFT) |
1248 | #define MIN_LARGE_SIZE (SIZE_T_ONE << TREEBIN_SHIFT) |
1249 | #define MAX_SMALL_SIZE (MIN_LARGE_SIZE - SIZE_T_ONE) |
1249 | #define MAX_SMALL_SIZE (MIN_LARGE_SIZE - SIZE_T_ONE) |
1250 | #define MAX_SMALL_REQUEST (MAX_SMALL_SIZE - CHUNK_ALIGN_MASK - CHUNK_OVERHEAD) |
1250 | #define MAX_SMALL_REQUEST (MAX_SMALL_SIZE - CHUNK_ALIGN_MASK - CHUNK_OVERHEAD) |
1251 | 1251 | ||
1252 | struct malloc_state { |
1252 | struct malloc_state { |
1253 | binmap_t smallmap; |
1253 | binmap_t smallmap; |
1254 | binmap_t treemap; |
1254 | binmap_t treemap; |
1255 | size_t dvsize; |
1255 | size_t dvsize; |
1256 | size_t topsize; |
1256 | size_t topsize; |
1257 | char* least_addr; |
1257 | char* least_addr; |
1258 | mchunkptr dv; |
1258 | mchunkptr dv; |
1259 | mchunkptr top; |
1259 | mchunkptr top; |
1260 | size_t trim_check; |
1260 | size_t trim_check; |
1261 | size_t release_checks; |
1261 | size_t release_checks; |
1262 | size_t magic; |
1262 | size_t magic; |
1263 | mchunkptr smallbins[(NSMALLBINS+1)*2]; |
1263 | mchunkptr smallbins[(NSMALLBINS+1)*2]; |
1264 | tbinptr treebins[NTREEBINS]; |
1264 | tbinptr treebins[NTREEBINS]; |
1265 | size_t footprint; |
1265 | size_t footprint; |
1266 | size_t max_footprint; |
1266 | size_t max_footprint; |
1267 | size_t footprint_limit; /* zero means no limit */ |
1267 | size_t footprint_limit; /* zero means no limit */ |
1268 | flag_t mflags; |
1268 | flag_t mflags; |
1269 | struct mutex lock; /* locate lock among fields that rarely change */ |
1269 | struct mutex lock; /* locate lock among fields that rarely change */ |
1270 | msegment seg; |
1270 | msegment seg; |
1271 | void* extp; /* Unused but available for extensions */ |
1271 | void* extp; /* Unused but available for extensions */ |
1272 | size_t exts; |
1272 | size_t exts; |
1273 | }; |
1273 | }; |
1274 | 1274 | ||
1275 | typedef struct malloc_state* mstate; |
1275 | typedef struct malloc_state* mstate; |
1276 | 1276 | ||
1277 | /* ------------- Global malloc_state and malloc_params ------------------- */ |
1277 | /* ------------- Global malloc_state and malloc_params ------------------- */ |
1278 | 1278 | ||
1279 | /* |
1279 | /* |
1280 | malloc_params holds global properties, including those that can be |
1280 | malloc_params holds global properties, including those that can be |
1281 | dynamically set using mallopt. There is a single instance, mparams, |
1281 | dynamically set using mallopt. There is a single instance, mparams, |
1282 | initialized in init_mparams. Note that the non-zeroness of "magic" |
1282 | initialized in init_mparams. Note that the non-zeroness of "magic" |
1283 | also serves as an initialization flag. |
1283 | also serves as an initialization flag. |
1284 | */ |
1284 | */ |
1285 | 1285 | ||
1286 | struct malloc_params { |
1286 | struct malloc_params { |
1287 | size_t magic; |
1287 | size_t magic; |
1288 | size_t page_size; |
1288 | size_t page_size; |
1289 | size_t granularity; |
1289 | size_t granularity; |
1290 | size_t mmap_threshold; |
1290 | size_t mmap_threshold; |
1291 | size_t trim_threshold; |
1291 | size_t trim_threshold; |
1292 | flag_t default_mflags; |
1292 | flag_t default_mflags; |
1293 | }; |
1293 | }; |
1294 | 1294 | ||
1295 | static struct malloc_params mparams; |
1295 | static struct malloc_params mparams; |
1296 | 1296 | ||
1297 | /* Ensure mparams initialized */ |
1297 | /* Ensure mparams initialized */ |
1298 | #define ensure_initialization() (void)(mparams.magic != 0 || init_mparams()) |
1298 | #define ensure_initialization() (void)(mparams.magic != 0 || init_mparams()) |
1299 | 1299 | ||
1300 | static struct malloc_state _gm_; |
1300 | static struct malloc_state _gm_; |
1301 | #define gm (&_gm_) |
1301 | #define gm (&_gm_) |
1302 | #define is_global(M) ((M) == &_gm_) |
1302 | #define is_global(M) ((M) == &_gm_) |
1303 | 1303 | ||
1304 | #define is_initialized(M) ((M)->top != 0) |
1304 | #define is_initialized(M) ((M)->top != 0) |
1305 | 1305 | ||
1306 | /* -------------------------- system alloc setup ------------------------- */ |
1306 | /* -------------------------- system alloc setup ------------------------- */ |
1307 | 1307 | ||
1308 | /* Operations on mflags */ |
1308 | /* Operations on mflags */ |
1309 | 1309 | ||
1310 | #define use_lock(M) ((M)->mflags & USE_LOCK_BIT) |
1310 | #define use_lock(M) ((M)->mflags & USE_LOCK_BIT) |
1311 | #define enable_lock(M) ((M)->mflags |= USE_LOCK_BIT) |
1311 | #define enable_lock(M) ((M)->mflags |= USE_LOCK_BIT) |
1312 | #if USE_LOCKS |
1312 | #if USE_LOCKS |
1313 | #define disable_lock(M) ((M)->mflags &= ~USE_LOCK_BIT) |
1313 | #define disable_lock(M) ((M)->mflags &= ~USE_LOCK_BIT) |
1314 | #else |
1314 | #else |
1315 | #define disable_lock(M) |
1315 | #define disable_lock(M) |
1316 | #endif |
1316 | #endif |
1317 | 1317 | ||
1318 | #define use_mmap(M) ((M)->mflags & USE_MMAP_BIT) |
1318 | #define use_mmap(M) ((M)->mflags & USE_MMAP_BIT) |
1319 | #define enable_mmap(M) ((M)->mflags |= USE_MMAP_BIT) |
1319 | #define enable_mmap(M) ((M)->mflags |= USE_MMAP_BIT) |
1320 | #if HAVE_MMAP |
1320 | #if HAVE_MMAP |
1321 | #define disable_mmap(M) ((M)->mflags &= ~USE_MMAP_BIT) |
1321 | #define disable_mmap(M) ((M)->mflags &= ~USE_MMAP_BIT) |
1322 | #else |
1322 | #else |
1323 | #define disable_mmap(M) |
1323 | #define disable_mmap(M) |
1324 | #endif |
1324 | #endif |
1325 | 1325 | ||
1326 | #define use_noncontiguous(M) ((M)->mflags & USE_NONCONTIGUOUS_BIT) |
1326 | #define use_noncontiguous(M) ((M)->mflags & USE_NONCONTIGUOUS_BIT) |
1327 | #define disable_contiguous(M) ((M)->mflags |= USE_NONCONTIGUOUS_BIT) |
1327 | #define disable_contiguous(M) ((M)->mflags |= USE_NONCONTIGUOUS_BIT) |
1328 | 1328 | ||
1329 | #define set_lock(M,L)\ |
1329 | #define set_lock(M,L)\ |
1330 | ((M)->mflags = (L)?\ |
1330 | ((M)->mflags = (L)?\ |
1331 | ((M)->mflags | USE_LOCK_BIT) :\ |
1331 | ((M)->mflags | USE_LOCK_BIT) :\ |
1332 | ((M)->mflags & ~USE_LOCK_BIT)) |
1332 | ((M)->mflags & ~USE_LOCK_BIT)) |
1333 | 1333 | ||
1334 | /* page-align a size */ |
1334 | /* page-align a size */ |
1335 | #define page_align(S)\ |
1335 | #define page_align(S)\ |
1336 | (((S) + (mparams.page_size - SIZE_T_ONE)) & ~(mparams.page_size - SIZE_T_ONE)) |
1336 | (((S) + (mparams.page_size - SIZE_T_ONE)) & ~(mparams.page_size - SIZE_T_ONE)) |
1337 | 1337 | ||
1338 | /* granularity-align a size */ |
1338 | /* granularity-align a size */ |
1339 | #define granularity_align(S)\ |
1339 | #define granularity_align(S)\ |
1340 | (((S) + (mparams.granularity - SIZE_T_ONE))\ |
1340 | (((S) + (mparams.granularity - SIZE_T_ONE))\ |
1341 | & ~(mparams.granularity - SIZE_T_ONE)) |
1341 | & ~(mparams.granularity - SIZE_T_ONE)) |
1342 | 1342 | ||
1343 | 1343 | ||
1344 | /* For mmap, use granularity alignment on windows, else page-align */ |
1344 | /* For mmap, use granularity alignment on windows, else page-align */ |
1345 | #ifdef WIN32 |
1345 | #ifdef WIN32 |
1346 | #define mmap_align(S) granularity_align(S) |
1346 | #define mmap_align(S) granularity_align(S) |
1347 | #else |
1347 | #else |
1348 | #define mmap_align(S) page_align(S) |
1348 | #define mmap_align(S) page_align(S) |
1349 | #endif |
1349 | #endif |
1350 | 1350 | ||
1351 | /* For sys_alloc, enough padding to ensure can malloc request on success */ |
1351 | /* For sys_alloc, enough padding to ensure can malloc request on success */ |
1352 | #define SYS_ALLOC_PADDING (TOP_FOOT_SIZE + MALLOC_ALIGNMENT) |
1352 | #define SYS_ALLOC_PADDING (TOP_FOOT_SIZE + MALLOC_ALIGNMENT) |
1353 | 1353 | ||
1354 | #define is_page_aligned(S)\ |
1354 | #define is_page_aligned(S)\ |
1355 | (((size_t)(S) & (mparams.page_size - SIZE_T_ONE)) == 0) |
1355 | (((size_t)(S) & (mparams.page_size - SIZE_T_ONE)) == 0) |
1356 | #define is_granularity_aligned(S)\ |
1356 | #define is_granularity_aligned(S)\ |
1357 | (((size_t)(S) & (mparams.granularity - SIZE_T_ONE)) == 0) |
1357 | (((size_t)(S) & (mparams.granularity - SIZE_T_ONE)) == 0) |
1358 | 1358 | ||
1359 | /* True if segment S holds address A */ |
1359 | /* True if segment S holds address A */ |
1360 | #define segment_holds(S, A)\ |
1360 | #define segment_holds(S, A)\ |
1361 | ((char*)(A) >= S->base && (char*)(A) < S->base + S->size) |
1361 | ((char*)(A) >= S->base && (char*)(A) < S->base + S->size) |
1362 | 1362 | ||
1363 | /* Return segment holding given address */ |
1363 | /* Return segment holding given address */ |
1364 | static msegmentptr segment_holding(mstate m, char* addr) { |
1364 | static msegmentptr segment_holding(mstate m, char* addr) { |
1365 | msegmentptr sp = &m->seg; |
1365 | msegmentptr sp = &m->seg; |
1366 | for (;;) { |
1366 | for (;;) { |
1367 | if (addr >= sp->base && addr < sp->base + sp->size) |
1367 | if (addr >= sp->base && addr < sp->base + sp->size) |
1368 | return sp; |
1368 | return sp; |
1369 | if ((sp = sp->next) == 0) |
1369 | if ((sp = sp->next) == 0) |
1370 | return 0; |
1370 | return 0; |
1371 | } |
1371 | } |
1372 | } |
1372 | } |
1373 | 1373 | ||
1374 | /* Return true if segment contains a segment link */ |
1374 | /* Return true if segment contains a segment link */ |
1375 | static int has_segment_link(mstate m, msegmentptr ss) { |
1375 | static int has_segment_link(mstate m, msegmentptr ss) { |
1376 | msegmentptr sp = &m->seg; |
1376 | msegmentptr sp = &m->seg; |
1377 | for (;;) { |
1377 | for (;;) { |
1378 | if ((char*)sp >= ss->base && (char*)sp < ss->base + ss->size) |
1378 | if ((char*)sp >= ss->base && (char*)sp < ss->base + ss->size) |
1379 | return 1; |
1379 | return 1; |
1380 | if ((sp = sp->next) == 0) |
1380 | if ((sp = sp->next) == 0) |
1381 | return 0; |
1381 | return 0; |
1382 | } |
1382 | } |
1383 | } |
1383 | } |
1384 | 1384 | ||
1385 | 1385 | ||
1386 | /* |
1386 | /* |
1387 | TOP_FOOT_SIZE is padding at the end of a segment, including space |
1387 | TOP_FOOT_SIZE is padding at the end of a segment, including space |
1388 | that may be needed to place segment records and fenceposts when new |
1388 | that may be needed to place segment records and fenceposts when new |
1389 | noncontiguous segments are added. |
1389 | noncontiguous segments are added. |
1390 | */ |
1390 | */ |
1391 | #define TOP_FOOT_SIZE\ |
1391 | #define TOP_FOOT_SIZE\ |
1392 | (align_offset(chunk2mem(0))+pad_request(sizeof(struct malloc_segment))+MIN_CHUNK_SIZE) |
1392 | (align_offset(chunk2mem(0))+pad_request(sizeof(struct malloc_segment))+MIN_CHUNK_SIZE) |
1393 | 1393 | ||
1394 | 1394 | ||
1395 | /* ------------------------------- Hooks -------------------------------- */ |
1395 | /* ------------------------------- Hooks -------------------------------- */ |
1396 | 1396 | ||
1397 | /* |
1397 | /* |
1398 | PREACTION should be defined to return 0 on success, and nonzero on |
1398 | PREACTION should be defined to return 0 on success, and nonzero on |
1399 | failure. If you are not using locking, you can redefine these to do |
1399 | failure. If you are not using locking, you can redefine these to do |
1400 | anything you like. |
1400 | anything you like. |
1401 | */ |
1401 | */ |
1402 | 1402 | ||
1403 | #define PREACTION(M) ( MutexLock(&(M)->lock)) |
1403 | #define PREACTION(M) ( MutexLock(&(M)->lock)) |
1404 | #define POSTACTION(M) { MutexUnlock(&(M)->lock); } |
1404 | #define POSTACTION(M) { MutexUnlock(&(M)->lock); } |
1405 | 1405 | ||
1406 | /* -------------------------- Debugging setup ---------------------------- */ |
1406 | /* -------------------------- Debugging setup ---------------------------- */ |
1407 | 1407 | ||
1408 | #if ! DEBUG |
1408 | #if ! DEBUG |
1409 | 1409 | ||
1410 | #define check_free_chunk(M,P) |
1410 | #define check_free_chunk(M,P) |
1411 | #define check_inuse_chunk(M,P) |
1411 | #define check_inuse_chunk(M,P) |
1412 | #define check_malloced_chunk(M,P,N) |
1412 | #define check_malloced_chunk(M,P,N) |
1413 | #define check_mmapped_chunk(M,P) |
1413 | #define check_mmapped_chunk(M,P) |
1414 | #define check_malloc_state(M) |
1414 | #define check_malloc_state(M) |
1415 | #define check_top_chunk(M,P) |
1415 | #define check_top_chunk(M,P) |
1416 | 1416 | ||
1417 | #else /* DEBUG */ |
1417 | #else /* DEBUG */ |
1418 | #define check_free_chunk(M,P) do_check_free_chunk(M,P) |
1418 | #define check_free_chunk(M,P) do_check_free_chunk(M,P) |
1419 | #define check_inuse_chunk(M,P) do_check_inuse_chunk(M,P) |
1419 | #define check_inuse_chunk(M,P) do_check_inuse_chunk(M,P) |
1420 | #define check_top_chunk(M,P) do_check_top_chunk(M,P) |
1420 | #define check_top_chunk(M,P) do_check_top_chunk(M,P) |
1421 | #define check_malloced_chunk(M,P,N) do_check_malloced_chunk(M,P,N) |
1421 | #define check_malloced_chunk(M,P,N) do_check_malloced_chunk(M,P,N) |
1422 | #define check_mmapped_chunk(M,P) do_check_mmapped_chunk(M,P) |
1422 | #define check_mmapped_chunk(M,P) do_check_mmapped_chunk(M,P) |
1423 | #define check_malloc_state(M) do_check_malloc_state(M) |
1423 | #define check_malloc_state(M) do_check_malloc_state(M) |
1424 | 1424 | ||
1425 | static void do_check_any_chunk(mstate m, mchunkptr p); |
1425 | static void do_check_any_chunk(mstate m, mchunkptr p); |
1426 | static void do_check_top_chunk(mstate m, mchunkptr p); |
1426 | static void do_check_top_chunk(mstate m, mchunkptr p); |
1427 | static void do_check_mmapped_chunk(mstate m, mchunkptr p); |
1427 | static void do_check_mmapped_chunk(mstate m, mchunkptr p); |
1428 | static void do_check_inuse_chunk(mstate m, mchunkptr p); |
1428 | static void do_check_inuse_chunk(mstate m, mchunkptr p); |
1429 | static void do_check_free_chunk(mstate m, mchunkptr p); |
1429 | static void do_check_free_chunk(mstate m, mchunkptr p); |
1430 | static void do_check_malloced_chunk(mstate m, void* mem, size_t s); |
1430 | static void do_check_malloced_chunk(mstate m, void* mem, size_t s); |
1431 | static void do_check_tree(mstate m, tchunkptr t); |
1431 | static void do_check_tree(mstate m, tchunkptr t); |
1432 | static void do_check_treebin(mstate m, bindex_t i); |
1432 | static void do_check_treebin(mstate m, bindex_t i); |
1433 | static void do_check_smallbin(mstate m, bindex_t i); |
1433 | static void do_check_smallbin(mstate m, bindex_t i); |
1434 | static void do_check_malloc_state(mstate m); |
1434 | static void do_check_malloc_state(mstate m); |
1435 | static int bin_find(mstate m, mchunkptr x); |
1435 | static int bin_find(mstate m, mchunkptr x); |
1436 | static size_t traverse_and_check(mstate m); |
1436 | static size_t traverse_and_check(mstate m); |
1437 | #endif /* DEBUG */ |
1437 | #endif /* DEBUG */ |
1438 | 1438 | ||
1439 | /* ---------------------------- Indexing Bins ---------------------------- */ |
1439 | /* ---------------------------- Indexing Bins ---------------------------- */ |
1440 | 1440 | ||
1441 | #define is_small(s) (((s) >> SMALLBIN_SHIFT) < NSMALLBINS) |
1441 | #define is_small(s) (((s) >> SMALLBIN_SHIFT) < NSMALLBINS) |
1442 | #define small_index(s) (bindex_t)((s) >> SMALLBIN_SHIFT) |
1442 | #define small_index(s) (bindex_t)((s) >> SMALLBIN_SHIFT) |
1443 | #define small_index2size(i) ((i) << SMALLBIN_SHIFT) |
1443 | #define small_index2size(i) ((i) << SMALLBIN_SHIFT) |
1444 | #define MIN_SMALL_INDEX (small_index(MIN_CHUNK_SIZE)) |
1444 | #define MIN_SMALL_INDEX (small_index(MIN_CHUNK_SIZE)) |
1445 | 1445 | ||
1446 | /* addressing by index. See above about smallbin repositioning */ |
1446 | /* addressing by index. See above about smallbin repositioning */ |
1447 | #define smallbin_at(M, i) ((sbinptr)((char*)&((M)->smallbins[(i)<<1]))) |
1447 | #define smallbin_at(M, i) ((sbinptr)((char*)&((M)->smallbins[(i)<<1]))) |
1448 | #define treebin_at(M,i) (&((M)->treebins[i])) |
1448 | #define treebin_at(M,i) (&((M)->treebins[i])) |
1449 | 1449 | ||
1450 | #define compute_tree_index(S, I)\ |
1450 | #define compute_tree_index(S, I)\ |
1451 | {\ |
1451 | {\ |
1452 | unsigned int X = S >> TREEBIN_SHIFT;\ |
1452 | unsigned int X = S >> TREEBIN_SHIFT;\ |
1453 | if (X == 0)\ |
1453 | if (X == 0)\ |
1454 | I = 0;\ |
1454 | I = 0;\ |
1455 | else if (X > 0xFFFF)\ |
1455 | else if (X > 0xFFFF)\ |
1456 | I = NTREEBINS-1;\ |
1456 | I = NTREEBINS-1;\ |
1457 | else {\ |
1457 | else {\ |
1458 | unsigned int K = (unsigned) sizeof(X)*__CHAR_BIT__ - 1 - (unsigned) __builtin_clz(X); \ |
1458 | unsigned int K = (unsigned) sizeof(X)*__CHAR_BIT__ - 1 - (unsigned) __builtin_clz(X); \ |
1459 | I = (bindex_t)((K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1)));\ |
1459 | I = (bindex_t)((K << 1) + ((S >> (K + (TREEBIN_SHIFT-1)) & 1)));\ |
1460 | }\ |
1460 | }\ |
1461 | } |
1461 | } |
1462 | 1462 | ||
1463 | 1463 | ||
1464 | 1464 | ||
1465 | /* Bit representing maximum resolved size in a treebin at i */ |
1465 | /* Bit representing maximum resolved size in a treebin at i */ |
1466 | #define bit_for_tree_index(i) \ |
1466 | #define bit_for_tree_index(i) \ |
1467 | (i == NTREEBINS-1)? (SIZE_T_BITSIZE-1) : (((i) >> 1) + TREEBIN_SHIFT - 2) |
1467 | (i == NTREEBINS-1)? (SIZE_T_BITSIZE-1) : (((i) >> 1) + TREEBIN_SHIFT - 2) |
1468 | 1468 | ||
1469 | /* Shift placing maximum resolved bit in a treebin at i as sign bit */ |
1469 | /* Shift placing maximum resolved bit in a treebin at i as sign bit */ |
1470 | #define leftshift_for_tree_index(i) \ |
1470 | #define leftshift_for_tree_index(i) \ |
1471 | ((i == NTREEBINS-1)? 0 : \ |
1471 | ((i == NTREEBINS-1)? 0 : \ |
1472 | ((SIZE_T_BITSIZE-SIZE_T_ONE) - (((i) >> 1) + TREEBIN_SHIFT - 2))) |
1472 | ((SIZE_T_BITSIZE-SIZE_T_ONE) - (((i) >> 1) + TREEBIN_SHIFT - 2))) |
1473 | 1473 | ||
1474 | /* The size of the smallest chunk held in bin with index i */ |
1474 | /* The size of the smallest chunk held in bin with index i */ |
1475 | #define minsize_for_tree_index(i) \ |
1475 | #define minsize_for_tree_index(i) \ |
1476 | ((SIZE_T_ONE << (((i) >> 1) + TREEBIN_SHIFT)) | \ |
1476 | ((SIZE_T_ONE << (((i) >> 1) + TREEBIN_SHIFT)) | \ |
1477 | (((size_t)((i) & SIZE_T_ONE)) << (((i) >> 1) + TREEBIN_SHIFT - 1))) |
1477 | (((size_t)((i) & SIZE_T_ONE)) << (((i) >> 1) + TREEBIN_SHIFT - 1))) |
1478 | 1478 | ||
1479 | 1479 | ||
1480 | /* ------------------------ Operations on bin maps ----------------------- */ |
1480 | /* ------------------------ Operations on bin maps ----------------------- */ |
1481 | 1481 | ||
1482 | /* bit corresponding to given index */ |
1482 | /* bit corresponding to given index */ |
1483 | #define idx2bit(i) ((binmap_t)(1) << (i)) |
1483 | #define idx2bit(i) ((binmap_t)(1) << (i)) |
1484 | 1484 | ||
1485 | /* Mark/Clear bits with given index */ |
1485 | /* Mark/Clear bits with given index */ |
1486 | #define mark_smallmap(M,i) ((M)->smallmap |= idx2bit(i)) |
1486 | #define mark_smallmap(M,i) ((M)->smallmap |= idx2bit(i)) |
1487 | #define clear_smallmap(M,i) ((M)->smallmap &= ~idx2bit(i)) |
1487 | #define clear_smallmap(M,i) ((M)->smallmap &= ~idx2bit(i)) |
1488 | #define smallmap_is_marked(M,i) ((M)->smallmap & idx2bit(i)) |
1488 | #define smallmap_is_marked(M,i) ((M)->smallmap & idx2bit(i)) |
1489 | 1489 | ||
1490 | #define mark_treemap(M,i) ((M)->treemap |= idx2bit(i)) |
1490 | #define mark_treemap(M,i) ((M)->treemap |= idx2bit(i)) |
1491 | #define clear_treemap(M,i) ((M)->treemap &= ~idx2bit(i)) |
1491 | #define clear_treemap(M,i) ((M)->treemap &= ~idx2bit(i)) |
1492 | #define treemap_is_marked(M,i) ((M)->treemap & idx2bit(i)) |
1492 | #define treemap_is_marked(M,i) ((M)->treemap & idx2bit(i)) |
1493 | 1493 | ||
1494 | /* isolate the least set bit of a bitmap */ |
1494 | /* isolate the least set bit of a bitmap */ |
1495 | #define least_bit(x) ((x) & -(x)) |
1495 | #define least_bit(x) ((x) & -(x)) |
1496 | 1496 | ||
1497 | /* mask with all bits to left of least bit of x on */ |
1497 | /* mask with all bits to left of least bit of x on */ |
1498 | #define left_bits(x) ((x<<1) | -(x<<1)) |
1498 | #define left_bits(x) ((x<<1) | -(x<<1)) |
1499 | 1499 | ||
1500 | /* mask with all bits to left of or equal to least bit of x on */ |
1500 | /* mask with all bits to left of or equal to least bit of x on */ |
1501 | #define same_or_left_bits(x) ((x) | -(x)) |
1501 | #define same_or_left_bits(x) ((x) | -(x)) |
1502 | 1502 | ||
1503 | #define compute_bit2idx(X, I)\ |
1503 | #define compute_bit2idx(X, I)\ |
1504 | {\ |
1504 | {\ |
1505 | unsigned int J;\ |
1505 | unsigned int J;\ |
1506 | J = __builtin_ctz(X); \ |
1506 | J = __builtin_ctz(X); \ |
1507 | I = (bindex_t)J;\ |
1507 | I = (bindex_t)J;\ |
1508 | } |
1508 | } |
1509 | 1509 | ||
1510 | /* ----------------------- Runtime Check Support ------------------------- */ |
1510 | /* ----------------------- Runtime Check Support ------------------------- */ |
1511 | 1511 | ||
1512 | /* |
1512 | /* |
1513 | For security, the main invariant is that malloc/free/etc never |
1513 | For security, the main invariant is that malloc/free/etc never |
1514 | writes to a static address other than malloc_state, unless static |
1514 | writes to a static address other than malloc_state, unless static |
1515 | malloc_state itself has been corrupted, which cannot occur via |
1515 | malloc_state itself has been corrupted, which cannot occur via |
1516 | malloc (because of these checks). In essence this means that we |
1516 | malloc (because of these checks). In essence this means that we |
1517 | believe all pointers, sizes, maps etc held in malloc_state, but |
1517 | believe all pointers, sizes, maps etc held in malloc_state, but |
1518 | check all of those linked or offsetted from other embedded data |
1518 | check all of those linked or offsetted from other embedded data |
1519 | structures. These checks are interspersed with main code in a way |
1519 | structures. These checks are interspersed with main code in a way |
1520 | that tends to minimize their run-time cost. |
1520 | that tends to minimize their run-time cost. |
1521 | 1521 | ||
1522 | When FOOTERS is defined, in addition to range checking, we also |
1522 | When FOOTERS is defined, in addition to range checking, we also |
1523 | verify footer fields of inuse chunks, which can be used guarantee |
1523 | verify footer fields of inuse chunks, which can be used guarantee |
1524 | that the mstate controlling malloc/free is intact. This is a |
1524 | that the mstate controlling malloc/free is intact. This is a |
1525 | streamlined version of the approach described by William Robertson |
1525 | streamlined version of the approach described by William Robertson |
1526 | et al in "Run-time Detection of Heap-based Overflows" LISA'03 |
1526 | et al in "Run-time Detection of Heap-based Overflows" LISA'03 |
1527 | http://www.usenix.org/events/lisa03/tech/robertson.html The footer |
1527 | http://www.usenix.org/events/lisa03/tech/robertson.html The footer |
1528 | of an inuse chunk holds the xor of its mstate and a random seed, |
1528 | of an inuse chunk holds the xor of its mstate and a random seed, |
1529 | that is checked upon calls to free() and realloc(). This is |
1529 | that is checked upon calls to free() and realloc(). This is |
1530 | (probabalistically) unguessable from outside the program, but can be |
1530 | (probabalistically) unguessable from outside the program, but can be |
1531 | computed by any code successfully malloc'ing any chunk, so does not |
1531 | computed by any code successfully malloc'ing any chunk, so does not |
1532 | itself provide protection against code that has already broken |
1532 | itself provide protection against code that has already broken |
1533 | security through some other means. Unlike Robertson et al, we |
1533 | security through some other means. Unlike Robertson et al, we |
1534 | always dynamically check addresses of all offset chunks (previous, |
1534 | always dynamically check addresses of all offset chunks (previous, |
1535 | next, etc). This turns out to be cheaper than relying on hashes. |
1535 | next, etc). This turns out to be cheaper than relying on hashes. |
1536 | */ |
1536 | */ |
1537 | 1537 | ||
1538 | #if !INSECURE |
1538 | #if !INSECURE |
1539 | /* Check if address a is at least as high as any from MORECORE or MMAP */ |
1539 | /* Check if address a is at least as high as any from MORECORE or MMAP */ |
1540 | #define ok_address(M, a) ((char*)(a) >= (M)->least_addr) |
1540 | #define ok_address(M, a) ((char*)(a) >= (M)->least_addr) |
1541 | /* Check if address of next chunk n is higher than base chunk p */ |
1541 | /* Check if address of next chunk n is higher than base chunk p */ |
1542 | #define ok_next(p, n) ((char*)(p) < (char*)(n)) |
1542 | #define ok_next(p, n) ((char*)(p) < (char*)(n)) |
1543 | /* Check if p has inuse status */ |
1543 | /* Check if p has inuse status */ |
1544 | #define ok_inuse(p) is_inuse(p) |
1544 | #define ok_inuse(p) is_inuse(p) |
1545 | /* Check if p has its pinuse bit on */ |
1545 | /* Check if p has its pinuse bit on */ |
1546 | #define ok_pinuse(p) pinuse(p) |
1546 | #define ok_pinuse(p) pinuse(p) |
1547 | 1547 | ||
1548 | #else /* !INSECURE */ |
1548 | #else /* !INSECURE */ |
1549 | #define ok_address(M, a) (1) |
1549 | #define ok_address(M, a) (1) |
1550 | #define ok_next(b, n) (1) |
1550 | #define ok_next(b, n) (1) |
1551 | #define ok_inuse(p) (1) |
1551 | #define ok_inuse(p) (1) |
1552 | #define ok_pinuse(p) (1) |
1552 | #define ok_pinuse(p) (1) |
1553 | #endif /* !INSECURE */ |
1553 | #endif /* !INSECURE */ |
1554 | 1554 | ||
1555 | #if (FOOTERS && !INSECURE) |
1555 | #if (FOOTERS && !INSECURE) |
1556 | /* Check if (alleged) mstate m has expected magic field */ |
1556 | /* Check if (alleged) mstate m has expected magic field */ |
1557 | #define ok_magic(M) ((M)->magic == mparams.magic) |
1557 | #define ok_magic(M) ((M)->magic == mparams.magic) |
1558 | #else /* (FOOTERS && !INSECURE) */ |
1558 | #else /* (FOOTERS && !INSECURE) */ |
1559 | #define ok_magic(M) (1) |
1559 | #define ok_magic(M) (1) |
1560 | #endif /* (FOOTERS && !INSECURE) */ |
1560 | #endif /* (FOOTERS && !INSECURE) */ |
1561 | 1561 | ||
1562 | /* In gcc, use __builtin_expect to minimize impact of checks */ |
1562 | /* In gcc, use __builtin_expect to minimize impact of checks */ |
1563 | #if !INSECURE |
1563 | #if !INSECURE |
1564 | #if defined(__GNUC__) && __GNUC__ >= 3 |
1564 | #if defined(__GNUC__) && __GNUC__ >= 3 |
1565 | #define RTCHECK(e) __builtin_expect(e, 1) |
1565 | #define RTCHECK(e) __builtin_expect(e, 1) |
1566 | #else /* GNUC */ |
1566 | #else /* GNUC */ |
1567 | #define RTCHECK(e) (e) |
1567 | #define RTCHECK(e) (e) |
1568 | #endif /* GNUC */ |
1568 | #endif /* GNUC */ |
1569 | #else /* !INSECURE */ |
1569 | #else /* !INSECURE */ |
1570 | #define RTCHECK(e) (1) |
1570 | #define RTCHECK(e) (1) |
1571 | #endif /* !INSECURE */ |
1571 | #endif /* !INSECURE */ |
1572 | 1572 | ||
1573 | /* macros to set up inuse chunks with or without footers */ |
1573 | /* macros to set up inuse chunks with or without footers */ |
1574 | 1574 | ||
1575 | #if !FOOTERS |
1575 | #if !FOOTERS |
1576 | 1576 | ||
1577 | #define mark_inuse_foot(M,p,s) |
1577 | #define mark_inuse_foot(M,p,s) |
1578 | 1578 | ||
1579 | /* Macros for setting head/foot of non-mmapped chunks */ |
1579 | /* Macros for setting head/foot of non-mmapped chunks */ |
1580 | 1580 | ||
1581 | /* Set cinuse bit and pinuse bit of next chunk */ |
1581 | /* Set cinuse bit and pinuse bit of next chunk */ |
1582 | #define set_inuse(M,p,s)\ |
1582 | #define set_inuse(M,p,s)\ |
1583 | ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ |
1583 | ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ |
1584 | ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) |
1584 | ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) |
1585 | 1585 | ||
1586 | /* Set cinuse and pinuse of this chunk and pinuse of next chunk */ |
1586 | /* Set cinuse and pinuse of this chunk and pinuse of next chunk */ |
1587 | #define set_inuse_and_pinuse(M,p,s)\ |
1587 | #define set_inuse_and_pinuse(M,p,s)\ |
1588 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ |
1588 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ |
1589 | ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) |
1589 | ((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT) |
1590 | 1590 | ||
1591 | /* Set size, cinuse and pinuse bit of this chunk */ |
1591 | /* Set size, cinuse and pinuse bit of this chunk */ |
1592 | #define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ |
1592 | #define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ |
1593 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT)) |
1593 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT)) |
1594 | 1594 | ||
1595 | #else /* FOOTERS */ |
1595 | #else /* FOOTERS */ |
1596 | 1596 | ||
1597 | /* Set foot of inuse chunk to be xor of mstate and seed */ |
1597 | /* Set foot of inuse chunk to be xor of mstate and seed */ |
1598 | #define mark_inuse_foot(M,p,s)\ |
1598 | #define mark_inuse_foot(M,p,s)\ |
1599 | (((mchunkptr)((char*)(p) + (s)))->prev_foot = ((size_t)(M) ^ mparams.magic)) |
1599 | (((mchunkptr)((char*)(p) + (s)))->prev_foot = ((size_t)(M) ^ mparams.magic)) |
1600 | 1600 | ||
1601 | #define get_mstate_for(p)\ |
1601 | #define get_mstate_for(p)\ |
1602 | ((mstate)(((mchunkptr)((char*)(p) +\ |
1602 | ((mstate)(((mchunkptr)((char*)(p) +\ |
1603 | (chunksize(p))))->prev_foot ^ mparams.magic)) |
1603 | (chunksize(p))))->prev_foot ^ mparams.magic)) |
1604 | 1604 | ||
1605 | #define set_inuse(M,p,s)\ |
1605 | #define set_inuse(M,p,s)\ |
1606 | ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ |
1606 | ((p)->head = (((p)->head & PINUSE_BIT)|s|CINUSE_BIT),\ |
1607 | (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT), \ |
1607 | (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT), \ |
1608 | mark_inuse_foot(M,p,s)) |
1608 | mark_inuse_foot(M,p,s)) |
1609 | 1609 | ||
1610 | #define set_inuse_and_pinuse(M,p,s)\ |
1610 | #define set_inuse_and_pinuse(M,p,s)\ |
1611 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ |
1611 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ |
1612 | (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT),\ |
1612 | (((mchunkptr)(((char*)(p)) + (s)))->head |= PINUSE_BIT),\ |
1613 | mark_inuse_foot(M,p,s)) |
1613 | mark_inuse_foot(M,p,s)) |
1614 | 1614 | ||
1615 | #define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ |
1615 | #define set_size_and_pinuse_of_inuse_chunk(M, p, s)\ |
1616 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ |
1616 | ((p)->head = (s|PINUSE_BIT|CINUSE_BIT),\ |
1617 | mark_inuse_foot(M, p, s)) |
1617 | mark_inuse_foot(M, p, s)) |
1618 | 1618 | ||
1619 | #endif /* !FOOTERS */ |
1619 | #endif /* !FOOTERS */ |
1620 | 1620 | ||
1621 | /* ---------------------------- setting mparams -------------------------- */ |
1621 | /* ---------------------------- setting mparams -------------------------- */ |
1622 | 1622 | ||
1623 | #if LOCK_AT_FORK |
1623 | #if LOCK_AT_FORK |
1624 | static void pre_fork(void) { ACQUIRE_LOCK(&(gm)->mutex); } |
1624 | static void pre_fork(void) { ACQUIRE_LOCK(&(gm)->mutex); } |
1625 | static void post_fork_parent(void) { RELEASE_LOCK(&(gm)->mutex); } |
1625 | static void post_fork_parent(void) { RELEASE_LOCK(&(gm)->mutex); } |
1626 | static void post_fork_child(void) { INITIAL_LOCK(&(gm)->mutex); } |
1626 | static void post_fork_child(void) { INITIAL_LOCK(&(gm)->mutex); } |
1627 | #endif /* LOCK_AT_FORK */ |
1627 | #endif /* LOCK_AT_FORK */ |
1628 | 1628 | ||
1629 | /* Initialize mparams */ |
1629 | /* Initialize mparams */ |
1630 | static int init_mparams(void) { |
1630 | static int init_mparams(void) { |
1631 | 1631 | ||
1632 | ACQUIRE_MALLOC_GLOBAL_LOCK(); |
1632 | ACQUIRE_MALLOC_GLOBAL_LOCK(); |
1633 | if (mparams.magic == 0) { |
1633 | if (mparams.magic == 0) { |
1634 | size_t magic; |
1634 | size_t magic; |
1635 | size_t psize; |
1635 | size_t psize; |
1636 | size_t gsize; |
1636 | size_t gsize; |
1637 | 1637 | ||
1638 | psize = 4096; |
1638 | psize = 4096; |
1639 | gsize = ((DEFAULT_GRANULARITY != 0)? DEFAULT_GRANULARITY : psize); |
1639 | gsize = ((DEFAULT_GRANULARITY != 0)? DEFAULT_GRANULARITY : psize); |
1640 | 1640 | ||
1641 | mparams.granularity = gsize; |
1641 | mparams.granularity = gsize; |
1642 | mparams.page_size = psize; |
1642 | mparams.page_size = psize; |
1643 | mparams.mmap_threshold = DEFAULT_MMAP_THRESHOLD; |
1643 | mparams.mmap_threshold = DEFAULT_MMAP_THRESHOLD; |
1644 | mparams.trim_threshold = DEFAULT_TRIM_THRESHOLD; |
1644 | mparams.trim_threshold = DEFAULT_TRIM_THRESHOLD; |
1645 | mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT|USE_NONCONTIGUOUS_BIT; |
1645 | mparams.default_mflags = USE_LOCK_BIT|USE_MMAP_BIT|USE_NONCONTIGUOUS_BIT; |
1646 | 1646 | ||
1647 | /* Set up lock for main malloc area */ |
1647 | /* Set up lock for main malloc area */ |
1648 | gm->mflags = mparams.default_mflags; |
1648 | gm->mflags = mparams.default_mflags; |
1649 | MutexInit(&gm->lock); |
1649 | MutexInit(&gm->lock); |
1650 | 1650 | ||
1651 | { |
1651 | { |
1652 | magic = (size_t)&magic ^ (size_t)0x55555555U; |
1652 | magic = (size_t)&magic ^ (size_t)0x55555555U; |
1653 | magic |= (size_t)8U; /* ensure nonzero */ |
1653 | magic |= (size_t)8U; /* ensure nonzero */ |
1654 | magic &= ~(size_t)7U; /* improve chances of fault for bad values */ |
1654 | magic &= ~(size_t)7U; /* improve chances of fault for bad values */ |
1655 | /* Until memory modes commonly available, use volatile-write */ |
1655 | /* Until memory modes commonly available, use volatile-write */ |
1656 | (*(volatile size_t *)(&(mparams.magic))) = magic; |
1656 | (*(volatile size_t *)(&(mparams.magic))) = magic; |
1657 | } |
1657 | } |
1658 | } |
1658 | } |
1659 | 1659 | ||
1660 | RELEASE_MALLOC_GLOBAL_LOCK(); |
1660 | RELEASE_MALLOC_GLOBAL_LOCK(); |
1661 | return 1; |
1661 | return 1; |
1662 | } |
1662 | } |
1663 | 1663 | ||
1664 | 1664 | ||
1665 | #if DEBUG |
1665 | #if DEBUG |
1666 | /* ------------------------- Debugging Support --------------------------- */ |
1666 | /* ------------------------- Debugging Support --------------------------- */ |
1667 | 1667 | ||
1668 | /* Check properties of any chunk, whether free, inuse, mmapped etc */ |
1668 | /* Check properties of any chunk, whether free, inuse, mmapped etc */ |
1669 | static void do_check_any_chunk(mstate m, mchunkptr p) { |
1669 | static void do_check_any_chunk(mstate m, mchunkptr p) { |
1670 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); |
1670 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); |
1671 | assert(ok_address(m, p)); |
1671 | assert(ok_address(m, p)); |
1672 | } |
1672 | } |
1673 | 1673 | ||
1674 | /* Check properties of top chunk */ |
1674 | /* Check properties of top chunk */ |
1675 | static void do_check_top_chunk(mstate m, mchunkptr p) { |
1675 | static void do_check_top_chunk(mstate m, mchunkptr p) { |
1676 | msegmentptr sp = segment_holding(m, (char*)p); |
1676 | msegmentptr sp = segment_holding(m, (char*)p); |
1677 | size_t sz = p->head & ~INUSE_BITS; /* third-lowest bit can be set! */ |
1677 | size_t sz = p->head & ~INUSE_BITS; /* third-lowest bit can be set! */ |
1678 | assert(sp != 0); |
1678 | assert(sp != 0); |
1679 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); |
1679 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); |
1680 | assert(ok_address(m, p)); |
1680 | assert(ok_address(m, p)); |
1681 | assert(sz == m->topsize); |
1681 | assert(sz == m->topsize); |
1682 | assert(sz > 0); |
1682 | assert(sz > 0); |
1683 | assert(sz == ((sp->base + sp->size) - (char*)p) - TOP_FOOT_SIZE); |
1683 | assert(sz == ((sp->base + sp->size) - (char*)p) - TOP_FOOT_SIZE); |
1684 | assert(pinuse(p)); |
1684 | assert(pinuse(p)); |
1685 | assert(!pinuse(chunk_plus_offset(p, sz))); |
1685 | assert(!pinuse(chunk_plus_offset(p, sz))); |
1686 | } |
1686 | } |
1687 | 1687 | ||
1688 | /* Check properties of (inuse) mmapped chunks */ |
1688 | /* Check properties of (inuse) mmapped chunks */ |
1689 | static void do_check_mmapped_chunk(mstate m, mchunkptr p) { |
1689 | static void do_check_mmapped_chunk(mstate m, mchunkptr p) { |
1690 | size_t sz = chunksize(p); |
1690 | size_t sz = chunksize(p); |
1691 | size_t len = (sz + (p->prev_foot) + MMAP_FOOT_PAD); |
1691 | size_t len = (sz + (p->prev_foot) + MMAP_FOOT_PAD); |
1692 | assert(is_mmapped(p)); |
1692 | assert(is_mmapped(p)); |
1693 | assert(use_mmap(m)); |
1693 | assert(use_mmap(m)); |
1694 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); |
1694 | assert((is_aligned(chunk2mem(p))) || (p->head == FENCEPOST_HEAD)); |
1695 | assert(ok_address(m, p)); |
1695 | assert(ok_address(m, p)); |
1696 | assert(!is_small(sz)); |
1696 | assert(!is_small(sz)); |
1697 | assert((len & (mparams.page_size-SIZE_T_ONE)) == 0); |
1697 | assert((len & (mparams.page_size-SIZE_T_ONE)) == 0); |
1698 | assert(chunk_plus_offset(p, sz)->head == FENCEPOST_HEAD); |
1698 | assert(chunk_plus_offset(p, sz)->head == FENCEPOST_HEAD); |
1699 | assert(chunk_plus_offset(p, sz+SIZE_T_SIZE)->head == 0); |
1699 | assert(chunk_plus_offset(p, sz+SIZE_T_SIZE)->head == 0); |
1700 | } |
1700 | } |
1701 | 1701 | ||
1702 | /* Check properties of inuse chunks */ |
1702 | /* Check properties of inuse chunks */ |
1703 | static void do_check_inuse_chunk(mstate m, mchunkptr p) { |
1703 | static void do_check_inuse_chunk(mstate m, mchunkptr p) { |
1704 | do_check_any_chunk(m, p); |
1704 | do_check_any_chunk(m, p); |
1705 | assert(is_inuse(p)); |
1705 | assert(is_inuse(p)); |
1706 | assert(next_pinuse(p)); |
1706 | assert(next_pinuse(p)); |
1707 | /* If not pinuse and not mmapped, previous chunk has OK offset */ |
1707 | /* If not pinuse and not mmapped, previous chunk has OK offset */ |
1708 | assert(is_mmapped(p) || pinuse(p) || next_chunk(prev_chunk(p)) == p); |
1708 | assert(is_mmapped(p) || pinuse(p) || next_chunk(prev_chunk(p)) == p); |
1709 | if (is_mmapped(p)) |
1709 | if (is_mmapped(p)) |
1710 | do_check_mmapped_chunk(m, p); |
1710 | do_check_mmapped_chunk(m, p); |
1711 | } |
1711 | } |
1712 | 1712 | ||
1713 | /* Check properties of free chunks */ |
1713 | /* Check properties of free chunks */ |
1714 | static void do_check_free_chunk(mstate m, mchunkptr p) { |
1714 | static void do_check_free_chunk(mstate m, mchunkptr p) { |
1715 | size_t sz = chunksize(p); |
1715 | size_t sz = chunksize(p); |
1716 | mchunkptr next = chunk_plus_offset(p, sz); |
1716 | mchunkptr next = chunk_plus_offset(p, sz); |
1717 | do_check_any_chunk(m, p); |
1717 | do_check_any_chunk(m, p); |
1718 | assert(!is_inuse(p)); |
1718 | assert(!is_inuse(p)); |
1719 | assert(!next_pinuse(p)); |
1719 | assert(!next_pinuse(p)); |
1720 | assert (!is_mmapped(p)); |
1720 | assert (!is_mmapped(p)); |
1721 | if (p != m->dv && p != m->top) { |
1721 | if (p != m->dv && p != m->top) { |
1722 | if (sz >= MIN_CHUNK_SIZE) { |
1722 | if (sz >= MIN_CHUNK_SIZE) { |
1723 | assert((sz & CHUNK_ALIGN_MASK) == 0); |
1723 | assert((sz & CHUNK_ALIGN_MASK) == 0); |
1724 | assert(is_aligned(chunk2mem(p))); |
1724 | assert(is_aligned(chunk2mem(p))); |
1725 | assert(next->prev_foot == sz); |
1725 | assert(next->prev_foot == sz); |
1726 | assert(pinuse(p)); |
1726 | assert(pinuse(p)); |
1727 | assert (next == m->top || is_inuse(next)); |
1727 | assert (next == m->top || is_inuse(next)); |
1728 | assert(p->fd->bk == p); |
1728 | assert(p->fd->bk == p); |
1729 | assert(p->bk->fd == p); |
1729 | assert(p->bk->fd == p); |
1730 | } |
1730 | } |
1731 | else /* markers are always of size SIZE_T_SIZE */ |
1731 | else /* markers are always of size SIZE_T_SIZE */ |
1732 | assert(sz == SIZE_T_SIZE); |
1732 | assert(sz == SIZE_T_SIZE); |
1733 | } |
1733 | } |
1734 | } |
1734 | } |
1735 | 1735 | ||
1736 | /* Check properties of malloced chunks at the point they are malloced */ |
1736 | /* Check properties of malloced chunks at the point they are malloced */ |
1737 | static void do_check_malloced_chunk(mstate m, void* mem, size_t s) { |
1737 | static void do_check_malloced_chunk(mstate m, void* mem, size_t s) { |
1738 | if (mem != 0) { |
1738 | if (mem != 0) { |
1739 | mchunkptr p = mem2chunk(mem); |
1739 | mchunkptr p = mem2chunk(mem); |
1740 | size_t sz = p->head & ~INUSE_BITS; |
1740 | size_t sz = p->head & ~INUSE_BITS; |
1741 | do_check_inuse_chunk(m, p); |
1741 | do_check_inuse_chunk(m, p); |
1742 | assert((sz & CHUNK_ALIGN_MASK) == 0); |
1742 | assert((sz & CHUNK_ALIGN_MASK) == 0); |
1743 | assert(sz >= MIN_CHUNK_SIZE); |
1743 | assert(sz >= MIN_CHUNK_SIZE); |
1744 | assert(sz >= s); |
1744 | assert(sz >= s); |
1745 | /* unless mmapped, size is less than MIN_CHUNK_SIZE more than request */ |
1745 | /* unless mmapped, size is less than MIN_CHUNK_SIZE more than request */ |
1746 | assert(is_mmapped(p) || sz < (s + MIN_CHUNK_SIZE)); |
1746 | assert(is_mmapped(p) || sz < (s + MIN_CHUNK_SIZE)); |
1747 | } |
1747 | } |
1748 | } |
1748 | } |
1749 | 1749 | ||
1750 | /* Check a tree and its subtrees. */ |
1750 | /* Check a tree and its subtrees. */ |
1751 | static void do_check_tree(mstate m, tchunkptr t) { |
1751 | static void do_check_tree(mstate m, tchunkptr t) { |
1752 | tchunkptr head = 0; |
1752 | tchunkptr head = 0; |
1753 | tchunkptr u = t; |
1753 | tchunkptr u = t; |
1754 | bindex_t tindex = t->index; |
1754 | bindex_t tindex = t->index; |
1755 | size_t tsize = chunksize(t); |
1755 | size_t tsize = chunksize(t); |
1756 | bindex_t idx; |
1756 | bindex_t idx; |
1757 | compute_tree_index(tsize, idx); |
1757 | compute_tree_index(tsize, idx); |
1758 | assert(tindex == idx); |
1758 | assert(tindex == idx); |
1759 | assert(tsize >= MIN_LARGE_SIZE); |
1759 | assert(tsize >= MIN_LARGE_SIZE); |
1760 | assert(tsize >= minsize_for_tree_index(idx)); |
1760 | assert(tsize >= minsize_for_tree_index(idx)); |
1761 | assert((idx == NTREEBINS-1) || (tsize < minsize_for_tree_index((idx+1)))); |
1761 | assert((idx == NTREEBINS-1) || (tsize < minsize_for_tree_index((idx+1)))); |
1762 | 1762 | ||
1763 | do { /* traverse through chain of same-sized nodes */ |
1763 | do { /* traverse through chain of same-sized nodes */ |
1764 | do_check_any_chunk(m, ((mchunkptr)u)); |
1764 | do_check_any_chunk(m, ((mchunkptr)u)); |
1765 | assert(u->index == tindex); |
1765 | assert(u->index == tindex); |
1766 | assert(chunksize(u) == tsize); |
1766 | assert(chunksize(u) == tsize); |
1767 | assert(!is_inuse(u)); |
1767 | assert(!is_inuse(u)); |
1768 | assert(!next_pinuse(u)); |
1768 | assert(!next_pinuse(u)); |
1769 | assert(u->fd->bk == u); |
1769 | assert(u->fd->bk == u); |
1770 | assert(u->bk->fd == u); |
1770 | assert(u->bk->fd == u); |
1771 | if (u->parent == 0) { |
1771 | if (u->parent == 0) { |
1772 | assert(u->child[0] == 0); |
1772 | assert(u->child[0] == 0); |
1773 | assert(u->child[1] == 0); |
1773 | assert(u->child[1] == 0); |
1774 | } |
1774 | } |
1775 | else { |
1775 | else { |
1776 | assert(head == 0); /* only one node on chain has parent */ |
1776 | assert(head == 0); /* only one node on chain has parent */ |
1777 | head = u; |
1777 | head = u; |
1778 | assert(u->parent != u); |
1778 | assert(u->parent != u); |
1779 | assert (u->parent->child[0] == u || |
1779 | assert (u->parent->child[0] == u || |
1780 | u->parent->child[1] == u || |
1780 | u->parent->child[1] == u || |
1781 | *((tbinptr*)(u->parent)) == u); |
1781 | *((tbinptr*)(u->parent)) == u); |
1782 | if (u->child[0] != 0) { |
1782 | if (u->child[0] != 0) { |
1783 | assert(u->child[0]->parent == u); |
1783 | assert(u->child[0]->parent == u); |
1784 | assert(u->child[0] != u); |
1784 | assert(u->child[0] != u); |
1785 | do_check_tree(m, u->child[0]); |
1785 | do_check_tree(m, u->child[0]); |
1786 | } |
1786 | } |
1787 | if (u->child[1] != 0) { |
1787 | if (u->child[1] != 0) { |
1788 | assert(u->child[1]->parent == u); |
1788 | assert(u->child[1]->parent == u); |
1789 | assert(u->child[1] != u); |
1789 | assert(u->child[1] != u); |
1790 | do_check_tree(m, u->child[1]); |
1790 | do_check_tree(m, u->child[1]); |
1791 | } |
1791 | } |
1792 | if (u->child[0] != 0 && u->child[1] != 0) { |
1792 | if (u->child[0] != 0 && u->child[1] != 0) { |
1793 | assert(chunksize(u->child[0]) < chunksize(u->child[1])); |
1793 | assert(chunksize(u->child[0]) < chunksize(u->child[1])); |
1794 | } |
1794 | } |
1795 | } |
1795 | } |
1796 | u = u->fd; |
1796 | u = u->fd; |
1797 | } while (u != t); |
1797 | } while (u != t); |
1798 | assert(head != 0); |
1798 | assert(head != 0); |
1799 | } |
1799 | } |
1800 | 1800 | ||
1801 | /* Check all the chunks in a treebin. */ |
1801 | /* Check all the chunks in a treebin. */ |
1802 | static void do_check_treebin(mstate m, bindex_t i) { |
1802 | static void do_check_treebin(mstate m, bindex_t i) { |
1803 | tbinptr* tb = treebin_at(m, i); |
1803 | tbinptr* tb = treebin_at(m, i); |
1804 | tchunkptr t = *tb; |
1804 | tchunkptr t = *tb; |
1805 | int empty = (m->treemap & (1U << i)) == 0; |
1805 | int empty = (m->treemap & (1U << i)) == 0; |
1806 | if (t == 0) |
1806 | if (t == 0) |
1807 | assert(empty); |
1807 | assert(empty); |
1808 | if (!empty) |
1808 | if (!empty) |
1809 | do_check_tree(m, t); |
1809 | do_check_tree(m, t); |
1810 | } |
1810 | } |
1811 | 1811 | ||
1812 | /* Check all the chunks in a smallbin. */ |
1812 | /* Check all the chunks in a smallbin. */ |
1813 | static void do_check_smallbin(mstate m, bindex_t i) { |
1813 | static void do_check_smallbin(mstate m, bindex_t i) { |
1814 | sbinptr b = smallbin_at(m, i); |
1814 | sbinptr b = smallbin_at(m, i); |
1815 | mchunkptr p = b->bk; |
1815 | mchunkptr p = b->bk; |
1816 | unsigned int empty = (m->smallmap & (1U << i)) == 0; |
1816 | unsigned int empty = (m->smallmap & (1U << i)) == 0; |
1817 | if (p == b) |
1817 | if (p == b) |
1818 | assert(empty); |
1818 | assert(empty); |
1819 | if (!empty) { |
1819 | if (!empty) { |
1820 | for (; p != b; p = p->bk) { |
1820 | for (; p != b; p = p->bk) { |
1821 | size_t size = chunksize(p); |
1821 | size_t size = chunksize(p); |
1822 | mchunkptr q; |
1822 | mchunkptr q; |
1823 | /* each chunk claims to be free */ |
1823 | /* each chunk claims to be free */ |
1824 | do_check_free_chunk(m, p); |
1824 | do_check_free_chunk(m, p); |
1825 | /* chunk belongs in bin */ |
1825 | /* chunk belongs in bin */ |
1826 | assert(small_index(size) == i); |
1826 | assert(small_index(size) == i); |
1827 | assert(p->bk == b || chunksize(p->bk) == chunksize(p)); |
1827 | assert(p->bk == b || chunksize(p->bk) == chunksize(p)); |
1828 | /* chunk is followed by an inuse chunk */ |
1828 | /* chunk is followed by an inuse chunk */ |
1829 | q = next_chunk(p); |
1829 | q = next_chunk(p); |
1830 | if (q->head != FENCEPOST_HEAD) |
1830 | if (q->head != FENCEPOST_HEAD) |
1831 | do_check_inuse_chunk(m, q); |
1831 | do_check_inuse_chunk(m, q); |
1832 | } |
1832 | } |
1833 | } |
1833 | } |
1834 | } |
1834 | } |
1835 | 1835 | ||
1836 | /* Find x in a bin. Used in other check functions. */ |
1836 | /* Find x in a bin. Used in other check functions. */ |
1837 | static int bin_find(mstate m, mchunkptr x) { |
1837 | static int bin_find(mstate m, mchunkptr x) { |
1838 | size_t size = chunksize(x); |
1838 | size_t size = chunksize(x); |
1839 | if (is_small(size)) { |
1839 | if (is_small(size)) { |
1840 | bindex_t sidx = small_index(size); |
1840 | bindex_t sidx = small_index(size); |
1841 | sbinptr b = smallbin_at(m, sidx); |
1841 | sbinptr b = smallbin_at(m, sidx); |
1842 | if (smallmap_is_marked(m, sidx)) { |
1842 | if (smallmap_is_marked(m, sidx)) { |
1843 | mchunkptr p = b; |
1843 | mchunkptr p = b; |
1844 | do { |
1844 | do { |
1845 | if (p == x) |
1845 | if (p == x) |
1846 | return 1; |
1846 | return 1; |
1847 | } while ((p = p->fd) != b); |
1847 | } while ((p = p->fd) != b); |
1848 | } |
1848 | } |
1849 | } |
1849 | } |
1850 | else { |
1850 | else { |
1851 | bindex_t tidx; |
1851 | bindex_t tidx; |
1852 | compute_tree_index(size, tidx); |
1852 | compute_tree_index(size, tidx); |
1853 | if (treemap_is_marked(m, tidx)) { |
1853 | if (treemap_is_marked(m, tidx)) { |
1854 | tchunkptr t = *treebin_at(m, tidx); |
1854 | tchunkptr t = *treebin_at(m, tidx); |
1855 | size_t sizebits = size << leftshift_for_tree_index(tidx); |
1855 | size_t sizebits = size << leftshift_for_tree_index(tidx); |
1856 | while (t != 0 && chunksize(t) != size) { |
1856 | while (t != 0 && chunksize(t) != size) { |
1857 | t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; |
1857 | t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; |
1858 | sizebits <<= 1; |
1858 | sizebits <<= 1; |
1859 | } |
1859 | } |
1860 | if (t != 0) { |
1860 | if (t != 0) { |
1861 | tchunkptr u = t; |
1861 | tchunkptr u = t; |
1862 | do { |
1862 | do { |
1863 | if (u == (tchunkptr)x) |
1863 | if (u == (tchunkptr)x) |
1864 | return 1; |
1864 | return 1; |
1865 | } while ((u = u->fd) != t); |
1865 | } while ((u = u->fd) != t); |
1866 | } |
1866 | } |
1867 | } |
1867 | } |
1868 | } |
1868 | } |
1869 | return 0; |
1869 | return 0; |
1870 | } |
1870 | } |
1871 | 1871 | ||
1872 | /* Traverse each chunk and check it; return total */ |
1872 | /* Traverse each chunk and check it; return total */ |
1873 | static size_t traverse_and_check(mstate m) { |
1873 | static size_t traverse_and_check(mstate m) { |
1874 | size_t sum = 0; |
1874 | size_t sum = 0; |
1875 | if (is_initialized(m)) { |
1875 | if (is_initialized(m)) { |
1876 | msegmentptr s = &m->seg; |
1876 | msegmentptr s = &m->seg; |
1877 | sum += m->topsize + TOP_FOOT_SIZE; |
1877 | sum += m->topsize + TOP_FOOT_SIZE; |
1878 | while (s != 0) { |
1878 | while (s != 0) { |
1879 | mchunkptr q = align_as_chunk(s->base); |
1879 | mchunkptr q = align_as_chunk(s->base); |
1880 | mchunkptr lastq = 0; |
1880 | mchunkptr lastq = 0; |
1881 | assert(pinuse(q)); |
1881 | assert(pinuse(q)); |
1882 | while (segment_holds(s, q) && |
1882 | while (segment_holds(s, q) && |
1883 | q != m->top && q->head != FENCEPOST_HEAD) { |
1883 | q != m->top && q->head != FENCEPOST_HEAD) { |
1884 | sum += chunksize(q); |
1884 | sum += chunksize(q); |
1885 | if (is_inuse(q)) { |
1885 | if (is_inuse(q)) { |
1886 | assert(!bin_find(m, q)); |
1886 | assert(!bin_find(m, q)); |
1887 | do_check_inuse_chunk(m, q); |
1887 | do_check_inuse_chunk(m, q); |
1888 | } |
1888 | } |
1889 | else { |
1889 | else { |
1890 | assert(q == m->dv || bin_find(m, q)); |
1890 | assert(q == m->dv || bin_find(m, q)); |
1891 | assert(lastq == 0 || is_inuse(lastq)); /* Not 2 consecutive free */ |
1891 | assert(lastq == 0 || is_inuse(lastq)); /* Not 2 consecutive free */ |
1892 | do_check_free_chunk(m, q); |
1892 | do_check_free_chunk(m, q); |
1893 | } |
1893 | } |
1894 | lastq = q; |
1894 | lastq = q; |
1895 | q = next_chunk(q); |
1895 | q = next_chunk(q); |
1896 | } |
1896 | } |
1897 | s = s->next; |
1897 | s = s->next; |
1898 | } |
1898 | } |
1899 | } |
1899 | } |
1900 | return sum; |
1900 | return sum; |
1901 | } |
1901 | } |
1902 | 1902 | ||
1903 | 1903 | ||
1904 | /* Check all properties of malloc_state. */ |
1904 | /* Check all properties of malloc_state. */ |
1905 | static void do_check_malloc_state(mstate m) { |
1905 | static void do_check_malloc_state(mstate m) { |
1906 | bindex_t i; |
1906 | bindex_t i; |
1907 | size_t total; |
1907 | size_t total; |
1908 | /* check bins */ |
1908 | /* check bins */ |
1909 | for (i = 0; i < NSMALLBINS; ++i) |
1909 | for (i = 0; i < NSMALLBINS; ++i) |
1910 | do_check_smallbin(m, i); |
1910 | do_check_smallbin(m, i); |
1911 | for (i = 0; i < NTREEBINS; ++i) |
1911 | for (i = 0; i < NTREEBINS; ++i) |
1912 | do_check_treebin(m, i); |
1912 | do_check_treebin(m, i); |
1913 | 1913 | ||
1914 | if (m->dvsize != 0) { /* check dv chunk */ |
1914 | if (m->dvsize != 0) { /* check dv chunk */ |
1915 | do_check_any_chunk(m, m->dv); |
1915 | do_check_any_chunk(m, m->dv); |
1916 | assert(m->dvsize == chunksize(m->dv)); |
1916 | assert(m->dvsize == chunksize(m->dv)); |
1917 | assert(m->dvsize >= MIN_CHUNK_SIZE); |
1917 | assert(m->dvsize >= MIN_CHUNK_SIZE); |
1918 | assert(bin_find(m, m->dv) == 0); |
1918 | assert(bin_find(m, m->dv) == 0); |
1919 | } |
1919 | } |
1920 | 1920 | ||
1921 | if (m->top != 0) { /* check top chunk */ |
1921 | if (m->top != 0) { /* check top chunk */ |
1922 | do_check_top_chunk(m, m->top); |
1922 | do_check_top_chunk(m, m->top); |
1923 | /*assert(m->topsize == chunksize(m->top)); redundant */ |
1923 | /*assert(m->topsize == chunksize(m->top)); redundant */ |
1924 | assert(m->topsize > 0); |
1924 | assert(m->topsize > 0); |
1925 | assert(bin_find(m, m->top) == 0); |
1925 | assert(bin_find(m, m->top) == 0); |
1926 | } |
1926 | } |
1927 | 1927 | ||
1928 | total = traverse_and_check(m); |
1928 | total = traverse_and_check(m); |
1929 | assert(total <= m->footprint); |
1929 | assert(total <= m->footprint); |
1930 | assert(m->footprint <= m->max_footprint); |
1930 | assert(m->footprint <= m->max_footprint); |
1931 | } |
1931 | } |
1932 | #endif /* DEBUG */ |
1932 | #endif /* DEBUG */ |
1933 | 1933 | ||
1934 | #define CORRUPTION_ERROR_ACTION(m) \ |
1934 | #define CORRUPTION_ERROR_ACTION(m) \ |
1935 | do { \ |
1935 | do { \ |
1936 | printf("%s malloc heap corrupted\n",__FUNCTION__); \ |
1936 | printf("%s malloc heap corrupted\n",__FUNCTION__); \ |
1937 | while(1) \ |
1937 | while(1) \ |
1938 | { \ |
1938 | { \ |
1939 | delay(100); \ |
1939 | delay(100); \ |
1940 | } \ |
1940 | } \ |
1941 | }while(0) \ |
1941 | }while(0) \ |
1942 | 1942 | ||
1943 | 1943 | ||
1944 | #define USAGE_ERROR_ACTION(m, p) \ |
1944 | #define USAGE_ERROR_ACTION(m, p) \ |
1945 | do { \ |
1945 | do { \ |
1946 | printf("%s malloc heap corrupted\n",__FUNCTION__); \ |
1946 | printf("%s malloc heap corrupted\n",__FUNCTION__); \ |
1947 | while(1) \ |
1947 | while(1) \ |
1948 | { \ |
1948 | { \ |
1949 | delay(100); \ |
1949 | delay(100); \ |
1950 | } \ |
1950 | } \ |
1951 | }while(0) \ |
1951 | }while(0) \ |
1952 | 1952 | ||
1953 | /* ----------------------- Operations on smallbins ----------------------- */ |
1953 | /* ----------------------- Operations on smallbins ----------------------- */ |
1954 | 1954 | ||
1955 | /* |
1955 | /* |
1956 | Various forms of linking and unlinking are defined as macros. Even |
1956 | Various forms of linking and unlinking are defined as macros. Even |
1957 | the ones for trees, which are very long but have very short typical |
1957 | the ones for trees, which are very long but have very short typical |
1958 | paths. This is ugly but reduces reliance on inlining support of |
1958 | paths. This is ugly but reduces reliance on inlining support of |
1959 | compilers. |
1959 | compilers. |
1960 | */ |
1960 | */ |
1961 | 1961 | ||
1962 | /* Link a free chunk into a smallbin */ |
1962 | /* Link a free chunk into a smallbin */ |
1963 | #define insert_small_chunk(M, P, S) {\ |
1963 | #define insert_small_chunk(M, P, S) {\ |
1964 | bindex_t I = small_index(S);\ |
1964 | bindex_t I = small_index(S);\ |
1965 | mchunkptr B = smallbin_at(M, I);\ |
1965 | mchunkptr B = smallbin_at(M, I);\ |
1966 | mchunkptr F = B;\ |
1966 | mchunkptr F = B;\ |
1967 | assert(S >= MIN_CHUNK_SIZE);\ |
1967 | assert(S >= MIN_CHUNK_SIZE);\ |
1968 | if (!smallmap_is_marked(M, I))\ |
1968 | if (!smallmap_is_marked(M, I))\ |
1969 | mark_smallmap(M, I);\ |
1969 | mark_smallmap(M, I);\ |
1970 | else if (RTCHECK(ok_address(M, B->fd)))\ |
1970 | else if (RTCHECK(ok_address(M, B->fd)))\ |
1971 | F = B->fd;\ |
1971 | F = B->fd;\ |
1972 | else {\ |
1972 | else {\ |
1973 | CORRUPTION_ERROR_ACTION(M);\ |
1973 | CORRUPTION_ERROR_ACTION(M);\ |
1974 | }\ |
1974 | }\ |
1975 | B->fd = P;\ |
1975 | B->fd = P;\ |
1976 | F->bk = P;\ |
1976 | F->bk = P;\ |
1977 | P->fd = F;\ |
1977 | P->fd = F;\ |
1978 | P->bk = B;\ |
1978 | P->bk = B;\ |
1979 | } |
1979 | } |
1980 | /* ----------------------- Operations on smallbins ----------------------- */ |
1980 | /* ----------------------- Operations on smallbins ----------------------- */ |
1981 | 1981 | ||
1982 | /* |
1982 | /* |
1983 | Various forms of linking and unlinking are defined as macros. Even |
1983 | Various forms of linking and unlinking are defined as macros. Even |
1984 | the ones for trees, which are very long but have very short typical |
1984 | the ones for trees, which are very long but have very short typical |
1985 | paths. This is ugly but reduces reliance on inlining support of |
1985 | paths. This is ugly but reduces reliance on inlining support of |
1986 | compilers. |
1986 | compilers. |
1987 | */ |
1987 | */ |
1988 | 1988 | ||
1989 | /* Link a free chunk into a smallbin */ |
1989 | /* Link a free chunk into a smallbin */ |
1990 | #define insert_small_chunk(M, P, S) {\ |
1990 | #define insert_small_chunk(M, P, S) {\ |
1991 | bindex_t I = small_index(S);\ |
1991 | bindex_t I = small_index(S);\ |
1992 | mchunkptr B = smallbin_at(M, I);\ |
1992 | mchunkptr B = smallbin_at(M, I);\ |
1993 | mchunkptr F = B;\ |
1993 | mchunkptr F = B;\ |
1994 | assert(S >= MIN_CHUNK_SIZE);\ |
1994 | assert(S >= MIN_CHUNK_SIZE);\ |
1995 | if (!smallmap_is_marked(M, I))\ |
1995 | if (!smallmap_is_marked(M, I))\ |
1996 | mark_smallmap(M, I);\ |
1996 | mark_smallmap(M, I);\ |
1997 | else if (RTCHECK(ok_address(M, B->fd)))\ |
1997 | else if (RTCHECK(ok_address(M, B->fd)))\ |
1998 | F = B->fd;\ |
1998 | F = B->fd;\ |
1999 | else {\ |
1999 | else {\ |
2000 | CORRUPTION_ERROR_ACTION(M);\ |
2000 | CORRUPTION_ERROR_ACTION(M);\ |
2001 | }\ |
2001 | }\ |
2002 | B->fd = P;\ |
2002 | B->fd = P;\ |
2003 | F->bk = P;\ |
2003 | F->bk = P;\ |
2004 | P->fd = F;\ |
2004 | P->fd = F;\ |
2005 | P->bk = B;\ |
2005 | P->bk = B;\ |
2006 | } |
2006 | } |
2007 | 2007 | ||
2008 | /* Unlink a chunk from a smallbin */ |
2008 | /* Unlink a chunk from a smallbin */ |
2009 | #define unlink_small_chunk(M, P, S) {\ |
2009 | #define unlink_small_chunk(M, P, S) {\ |
2010 | mchunkptr F = P->fd;\ |
2010 | mchunkptr F = P->fd;\ |
2011 | mchunkptr B = P->bk;\ |
2011 | mchunkptr B = P->bk;\ |
2012 | bindex_t I = small_index(S);\ |
2012 | bindex_t I = small_index(S);\ |
2013 | assert(P != B);\ |
2013 | assert(P != B);\ |
2014 | assert(P != F);\ |
2014 | assert(P != F);\ |
2015 | assert(chunksize(P) == small_index2size(I));\ |
2015 | assert(chunksize(P) == small_index2size(I));\ |
2016 | if (RTCHECK(F == smallbin_at(M,I) || (ok_address(M, F) && F->bk == P))) { \ |
2016 | if (RTCHECK(F == smallbin_at(M,I) || (ok_address(M, F) && F->bk == P))) { \ |
2017 | if (B == F) {\ |
2017 | if (B == F) {\ |
2018 | clear_smallmap(M, I);\ |
2018 | clear_smallmap(M, I);\ |
2019 | }\ |
2019 | }\ |
2020 | else if (RTCHECK(B == smallbin_at(M,I) ||\ |
2020 | else if (RTCHECK(B == smallbin_at(M,I) ||\ |
2021 | (ok_address(M, B) && B->fd == P))) {\ |
2021 | (ok_address(M, B) && B->fd == P))) {\ |
2022 | F->bk = B;\ |
2022 | F->bk = B;\ |
2023 | B->fd = F;\ |
2023 | B->fd = F;\ |
2024 | }\ |
2024 | }\ |
2025 | else {\ |
2025 | else {\ |
2026 | CORRUPTION_ERROR_ACTION(M);\ |
2026 | CORRUPTION_ERROR_ACTION(M);\ |
2027 | }\ |
2027 | }\ |
2028 | }\ |
2028 | }\ |
2029 | else {\ |
2029 | else {\ |
2030 | CORRUPTION_ERROR_ACTION(M);\ |
2030 | CORRUPTION_ERROR_ACTION(M);\ |
2031 | }\ |
2031 | }\ |
2032 | } |
2032 | } |
2033 | 2033 | ||
2034 | /* Unlink the first chunk from a smallbin */ |
2034 | /* Unlink the first chunk from a smallbin */ |
2035 | #define unlink_first_small_chunk(M, B, P, I) {\ |
2035 | #define unlink_first_small_chunk(M, B, P, I) {\ |
2036 | mchunkptr F = P->fd;\ |
2036 | mchunkptr F = P->fd;\ |
2037 | assert(P != B);\ |
2037 | assert(P != B);\ |
2038 | assert(P != F);\ |
2038 | assert(P != F);\ |
2039 | assert(chunksize(P) == small_index2size(I));\ |
2039 | assert(chunksize(P) == small_index2size(I));\ |
2040 | if (B == F) {\ |
2040 | if (B == F) {\ |
2041 | clear_smallmap(M, I);\ |
2041 | clear_smallmap(M, I);\ |
2042 | }\ |
2042 | }\ |
2043 | else if (RTCHECK(ok_address(M, F) && F->bk == P)) {\ |
2043 | else if (RTCHECK(ok_address(M, F) && F->bk == P)) {\ |
2044 | F->bk = B;\ |
2044 | F->bk = B;\ |
2045 | B->fd = F;\ |
2045 | B->fd = F;\ |
2046 | }\ |
2046 | }\ |
2047 | else {\ |
2047 | else {\ |
2048 | CORRUPTION_ERROR_ACTION(M);\ |
2048 | CORRUPTION_ERROR_ACTION(M);\ |
2049 | }\ |
2049 | }\ |
2050 | } |
2050 | } |
2051 | 2051 | ||
2052 | /* Replace dv node, binning the old one */ |
2052 | /* Replace dv node, binning the old one */ |
2053 | /* Used only when dvsize known to be small */ |
2053 | /* Used only when dvsize known to be small */ |
2054 | #define replace_dv(M, P, S) {\ |
2054 | #define replace_dv(M, P, S) {\ |
2055 | size_t DVS = M->dvsize;\ |
2055 | size_t DVS = M->dvsize;\ |
2056 | assert(is_small(DVS));\ |
2056 | assert(is_small(DVS));\ |
2057 | if (DVS != 0) {\ |
2057 | if (DVS != 0) {\ |
2058 | mchunkptr DV = M->dv;\ |
2058 | mchunkptr DV = M->dv;\ |
2059 | insert_small_chunk(M, DV, DVS);\ |
2059 | insert_small_chunk(M, DV, DVS);\ |
2060 | }\ |
2060 | }\ |
2061 | M->dvsize = S;\ |
2061 | M->dvsize = S;\ |
2062 | M->dv = P;\ |
2062 | M->dv = P;\ |
2063 | } |
2063 | } |
2064 | 2064 | ||
2065 | /* ------------------------- Operations on trees ------------------------- */ |
2065 | /* ------------------------- Operations on trees ------------------------- */ |
2066 | 2066 | ||
2067 | /* Insert chunk into tree */ |
2067 | /* Insert chunk into tree */ |
2068 | #define insert_large_chunk(M, X, S) {\ |
2068 | #define insert_large_chunk(M, X, S) {\ |
2069 | tbinptr* H;\ |
2069 | tbinptr* H;\ |
2070 | bindex_t I;\ |
2070 | bindex_t I;\ |
2071 | compute_tree_index(S, I);\ |
2071 | compute_tree_index(S, I);\ |
2072 | H = treebin_at(M, I);\ |
2072 | H = treebin_at(M, I);\ |
2073 | X->index = I;\ |
2073 | X->index = I;\ |
2074 | X->child[0] = X->child[1] = 0;\ |
2074 | X->child[0] = X->child[1] = 0;\ |
2075 | if (!treemap_is_marked(M, I)) {\ |
2075 | if (!treemap_is_marked(M, I)) {\ |
2076 | mark_treemap(M, I);\ |
2076 | mark_treemap(M, I);\ |
2077 | *H = X;\ |
2077 | *H = X;\ |
2078 | X->parent = (tchunkptr)H;\ |
2078 | X->parent = (tchunkptr)H;\ |
2079 | X->fd = X->bk = X;\ |
2079 | X->fd = X->bk = X;\ |
2080 | }\ |
2080 | }\ |
2081 | else {\ |
2081 | else {\ |
2082 | tchunkptr T = *H;\ |
2082 | tchunkptr T = *H;\ |
2083 | size_t K = S << leftshift_for_tree_index(I);\ |
2083 | size_t K = S << leftshift_for_tree_index(I);\ |
2084 | for (;;) {\ |
2084 | for (;;) {\ |
2085 | if (chunksize(T) != S) {\ |
2085 | if (chunksize(T) != S) {\ |
2086 | tchunkptr* C = &(T->child[(K >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]);\ |
2086 | tchunkptr* C = &(T->child[(K >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]);\ |
2087 | K <<= 1;\ |
2087 | K <<= 1;\ |
2088 | if (*C != 0)\ |
2088 | if (*C != 0)\ |
2089 | T = *C;\ |
2089 | T = *C;\ |
2090 | else if (RTCHECK(ok_address(M, C))) {\ |
2090 | else if (RTCHECK(ok_address(M, C))) {\ |
2091 | *C = X;\ |
2091 | *C = X;\ |
2092 | X->parent = T;\ |
2092 | X->parent = T;\ |
2093 | X->fd = X->bk = X;\ |
2093 | X->fd = X->bk = X;\ |
2094 | break;\ |
2094 | break;\ |
2095 | }\ |
2095 | }\ |
2096 | else {\ |
2096 | else {\ |
2097 | CORRUPTION_ERROR_ACTION(M);\ |
2097 | CORRUPTION_ERROR_ACTION(M);\ |
2098 | break;\ |
2098 | break;\ |
2099 | }\ |
2099 | }\ |
2100 | }\ |
2100 | }\ |
2101 | else {\ |
2101 | else {\ |
2102 | tchunkptr F = T->fd;\ |
2102 | tchunkptr F = T->fd;\ |
2103 | if (RTCHECK(ok_address(M, T) && ok_address(M, F))) {\ |
2103 | if (RTCHECK(ok_address(M, T) && ok_address(M, F))) {\ |
2104 | T->fd = F->bk = X;\ |
2104 | T->fd = F->bk = X;\ |
2105 | X->fd = F;\ |
2105 | X->fd = F;\ |
2106 | X->bk = T;\ |
2106 | X->bk = T;\ |
2107 | X->parent = 0;\ |
2107 | X->parent = 0;\ |
2108 | break;\ |
2108 | break;\ |
2109 | }\ |
2109 | }\ |
2110 | else {\ |
2110 | else {\ |
2111 | CORRUPTION_ERROR_ACTION(M);\ |
2111 | CORRUPTION_ERROR_ACTION(M);\ |
2112 | break;\ |
2112 | break;\ |
2113 | }\ |
2113 | }\ |
2114 | }\ |
2114 | }\ |
2115 | }\ |
2115 | }\ |
2116 | }\ |
2116 | }\ |
2117 | } |
2117 | } |
2118 | 2118 | ||
2119 | /* |
2119 | /* |
2120 | Unlink steps: |
2120 | Unlink steps: |
2121 | 2121 | ||
2122 | 1. If x is a chained node, unlink it from its same-sized fd/bk links |
2122 | 1. If x is a chained node, unlink it from its same-sized fd/bk links |
2123 | and choose its bk node as its replacement. |
2123 | and choose its bk node as its replacement. |
2124 | 2. If x was the last node of its size, but not a leaf node, it must |
2124 | 2. If x was the last node of its size, but not a leaf node, it must |
2125 | be replaced with a leaf node (not merely one with an open left or |
2125 | be replaced with a leaf node (not merely one with an open left or |
2126 | right), to make sure that lefts and rights of descendents |
2126 | right), to make sure that lefts and rights of descendents |
2127 | correspond properly to bit masks. We use the rightmost descendent |
2127 | correspond properly to bit masks. We use the rightmost descendent |
2128 | of x. We could use any other leaf, but this is easy to locate and |
2128 | of x. We could use any other leaf, but this is easy to locate and |
2129 | tends to counteract removal of leftmosts elsewhere, and so keeps |
2129 | tends to counteract removal of leftmosts elsewhere, and so keeps |
2130 | paths shorter than minimally guaranteed. This doesn't loop much |
2130 | paths shorter than minimally guaranteed. This doesn't loop much |
2131 | because on average a node in a tree is near the bottom. |
2131 | because on average a node in a tree is near the bottom. |
2132 | 3. If x is the base of a chain (i.e., has parent links) relink |
2132 | 3. If x is the base of a chain (i.e., has parent links) relink |
2133 | x's parent and children to x's replacement (or null if none). |
2133 | x's parent and children to x's replacement (or null if none). |
2134 | */ |
2134 | */ |
2135 | 2135 | ||
2136 | #define unlink_large_chunk(M, X) {\ |
2136 | #define unlink_large_chunk(M, X) {\ |
2137 | tchunkptr XP = X->parent;\ |
2137 | tchunkptr XP = X->parent;\ |
2138 | tchunkptr R;\ |
2138 | tchunkptr R;\ |
2139 | if (X->bk != X) {\ |
2139 | if (X->bk != X) {\ |
2140 | tchunkptr F = X->fd;\ |
2140 | tchunkptr F = X->fd;\ |
2141 | R = X->bk;\ |
2141 | R = X->bk;\ |
2142 | if (RTCHECK(ok_address(M, F) && F->bk == X && R->fd == X)) {\ |
2142 | if (RTCHECK(ok_address(M, F) && F->bk == X && R->fd == X)) {\ |
2143 | F->bk = R;\ |
2143 | F->bk = R;\ |
2144 | R->fd = F;\ |
2144 | R->fd = F;\ |
2145 | }\ |
2145 | }\ |
2146 | else {\ |
2146 | else {\ |
2147 | CORRUPTION_ERROR_ACTION(M);\ |
2147 | CORRUPTION_ERROR_ACTION(M);\ |
2148 | }\ |
2148 | }\ |
2149 | }\ |
2149 | }\ |
2150 | else {\ |
2150 | else {\ |
2151 | tchunkptr* RP;\ |
2151 | tchunkptr* RP;\ |
2152 | if (((R = *(RP = &(X->child[1]))) != 0) ||\ |
2152 | if (((R = *(RP = &(X->child[1]))) != 0) ||\ |
2153 | ((R = *(RP = &(X->child[0]))) != 0)) {\ |
2153 | ((R = *(RP = &(X->child[0]))) != 0)) {\ |
2154 | tchunkptr* CP;\ |
2154 | tchunkptr* CP;\ |
2155 | while ((*(CP = &(R->child[1])) != 0) ||\ |
2155 | while ((*(CP = &(R->child[1])) != 0) ||\ |
2156 | (*(CP = &(R->child[0])) != 0)) {\ |
2156 | (*(CP = &(R->child[0])) != 0)) {\ |
2157 | R = *(RP = CP);\ |
2157 | R = *(RP = CP);\ |
2158 | }\ |
2158 | }\ |
2159 | if (RTCHECK(ok_address(M, RP)))\ |
2159 | if (RTCHECK(ok_address(M, RP)))\ |
2160 | *RP = 0;\ |
2160 | *RP = 0;\ |
2161 | else {\ |
2161 | else {\ |
2162 | CORRUPTION_ERROR_ACTION(M);\ |
2162 | CORRUPTION_ERROR_ACTION(M);\ |
2163 | }\ |
2163 | }\ |
2164 | }\ |
2164 | }\ |
2165 | }\ |
2165 | }\ |
2166 | if (XP != 0) {\ |
2166 | if (XP != 0) {\ |
2167 | tbinptr* H = treebin_at(M, X->index);\ |
2167 | tbinptr* H = treebin_at(M, X->index);\ |
2168 | if (X == *H) {\ |
2168 | if (X == *H) {\ |
2169 | if ((*H = R) == 0) \ |
2169 | if ((*H = R) == 0) \ |
2170 | clear_treemap(M, X->index);\ |
2170 | clear_treemap(M, X->index);\ |
2171 | }\ |
2171 | }\ |
2172 | else if (RTCHECK(ok_address(M, XP))) {\ |
2172 | else if (RTCHECK(ok_address(M, XP))) {\ |
2173 | if (XP->child[0] == X) \ |
2173 | if (XP->child[0] == X) \ |
2174 | XP->child[0] = R;\ |
2174 | XP->child[0] = R;\ |
2175 | else \ |
2175 | else \ |
2176 | XP->child[1] = R;\ |
2176 | XP->child[1] = R;\ |
2177 | }\ |
2177 | }\ |
2178 | else\ |
2178 | else\ |
2179 | CORRUPTION_ERROR_ACTION(M);\ |
2179 | CORRUPTION_ERROR_ACTION(M);\ |
2180 | if (R != 0) {\ |
2180 | if (R != 0) {\ |
2181 | if (RTCHECK(ok_address(M, R))) {\ |
2181 | if (RTCHECK(ok_address(M, R))) {\ |
2182 | tchunkptr C0, C1;\ |
2182 | tchunkptr C0, C1;\ |
2183 | R->parent = XP;\ |
2183 | R->parent = XP;\ |
2184 | if ((C0 = X->child[0]) != 0) {\ |
2184 | if ((C0 = X->child[0]) != 0) {\ |
2185 | if (RTCHECK(ok_address(M, C0))) {\ |
2185 | if (RTCHECK(ok_address(M, C0))) {\ |
2186 | R->child[0] = C0;\ |
2186 | R->child[0] = C0;\ |
2187 | C0->parent = R;\ |
2187 | C0->parent = R;\ |
2188 | }\ |
2188 | }\ |
2189 | else\ |
2189 | else\ |
2190 | CORRUPTION_ERROR_ACTION(M);\ |
2190 | CORRUPTION_ERROR_ACTION(M);\ |
2191 | }\ |
2191 | }\ |
2192 | if ((C1 = X->child[1]) != 0) {\ |
2192 | if ((C1 = X->child[1]) != 0) {\ |
2193 | if (RTCHECK(ok_address(M, C1))) {\ |
2193 | if (RTCHECK(ok_address(M, C1))) {\ |
2194 | R->child[1] = C1;\ |
2194 | R->child[1] = C1;\ |
2195 | C1->parent = R;\ |
2195 | C1->parent = R;\ |
2196 | }\ |
2196 | }\ |
2197 | else\ |
2197 | else\ |
2198 | CORRUPTION_ERROR_ACTION(M);\ |
2198 | CORRUPTION_ERROR_ACTION(M);\ |
2199 | }\ |
2199 | }\ |
2200 | }\ |
2200 | }\ |
2201 | else\ |
2201 | else\ |
2202 | CORRUPTION_ERROR_ACTION(M);\ |
2202 | CORRUPTION_ERROR_ACTION(M);\ |
2203 | }\ |
2203 | }\ |
2204 | }\ |
2204 | }\ |
2205 | } |
2205 | } |
2206 | 2206 | ||
2207 | /* Relays to large vs small bin operations */ |
2207 | /* Relays to large vs small bin operations */ |
2208 | 2208 | ||
2209 | #define insert_chunk(M, P, S)\ |
2209 | #define insert_chunk(M, P, S)\ |
2210 | if (is_small(S)) insert_small_chunk(M, P, S)\ |
2210 | if (is_small(S)) insert_small_chunk(M, P, S)\ |
2211 | else { tchunkptr TP = (tchunkptr)(P); insert_large_chunk(M, TP, S); } |
2211 | else { tchunkptr TP = (tchunkptr)(P); insert_large_chunk(M, TP, S); } |
2212 | 2212 | ||
2213 | #define unlink_chunk(M, P, S)\ |
2213 | #define unlink_chunk(M, P, S)\ |
2214 | if (is_small(S)) unlink_small_chunk(M, P, S)\ |
2214 | if (is_small(S)) unlink_small_chunk(M, P, S)\ |
2215 | else { tchunkptr TP = (tchunkptr)(P); unlink_large_chunk(M, TP); } |
2215 | else { tchunkptr TP = (tchunkptr)(P); unlink_large_chunk(M, TP); } |
2216 | 2216 | ||
2217 | 2217 | ||
2218 | /* Relays to internal calls to malloc/free from realloc, memalign etc */ |
2218 | /* Relays to internal calls to malloc/free from realloc, memalign etc */ |
2219 | 2219 | ||
2220 | #if ONLY_MSPACES |
2220 | #if ONLY_MSPACES |
2221 | #define internal_malloc(m, b) mspace_malloc(m, b) |
2221 | #define internal_malloc(m, b) mspace_malloc(m, b) |
2222 | #define internal_free(m, mem) mspace_free(m,mem); |
2222 | #define internal_free(m, mem) mspace_free(m,mem); |
2223 | #else /* ONLY_MSPACES */ |
2223 | #else /* ONLY_MSPACES */ |
2224 | #if MSPACES |
2224 | #if MSPACES |
2225 | #define internal_malloc(m, b)\ |
2225 | #define internal_malloc(m, b)\ |
2226 | ((m == gm)? dlmalloc(b) : mspace_malloc(m, b)) |
2226 | ((m == gm)? dlmalloc(b) : mspace_malloc(m, b)) |
2227 | #define internal_free(m, mem)\ |
2227 | #define internal_free(m, mem)\ |
2228 | if (m == gm) dlfree(mem); else mspace_free(m,mem); |
2228 | if (m == gm) dlfree(mem); else mspace_free(m,mem); |
2229 | #else /* MSPACES */ |
2229 | #else /* MSPACES */ |
2230 | #define internal_malloc(m, b) malloc(b) |
2230 | #define internal_malloc(m, b) malloc(b) |
2231 | #define internal_free(m, mem) free(mem) |
2231 | #define internal_free(m, mem) free(mem) |
2232 | #endif /* MSPACES */ |
2232 | #endif /* MSPACES */ |
2233 | #endif /* ONLY_MSPACES */ |
2233 | #endif /* ONLY_MSPACES */ |
2234 | 2234 | ||
2235 | 2235 | ||
2236 | static inline void* os_mmap(size_t size) |
2236 | static inline void* os_mmap(size_t size) |
2237 | { |
2237 | { |
2238 | void* ptr = KernelAlloc(size); |
2238 | void* ptr = KernelAlloc(size); |
2239 | printf("%s %x %d bytes\n",__FUNCTION__, ptr, size); |
2239 | printf("%s %x %d bytes\n",__FUNCTION__, ptr, size); |
2240 | return (ptr != 0)? ptr: MFAIL; |
2240 | return (ptr != 0)? ptr: MFAIL; |
2241 | } |
2241 | } |
2242 | 2242 | ||
2243 | static inline int os_munmap(void* ptr, size_t size) |
2243 | static inline int os_munmap(void* ptr, size_t size) |
2244 | { |
2244 | { |
2245 | return (KernelFree(ptr) != 0) ? 0 : -1; |
2245 | return (KernelFree(ptr) != 0) ? 0 : -1; |
2246 | } |
2246 | } |
2247 | 2247 | ||
2248 | 2248 | ||
2249 | #define MMAP_DEFAULT(s) os_mmap(s) |
2249 | #define MMAP_DEFAULT(s) os_mmap(s) |
2250 | #define MUNMAP_DEFAULT(a, s) os_munmap((a), (s)) |
2250 | #define MUNMAP_DEFAULT(a, s) os_munmap((a), (s)) |
2251 | #define DIRECT_MMAP_DEFAULT(s) os_mmap(s) |
2251 | #define DIRECT_MMAP_DEFAULT(s) os_mmap(s) |
2252 | 2252 | ||
2253 | 2253 | ||
2254 | /* ----------------------- Direct-mmapping chunks ----------------------- */ |
2254 | /* ----------------------- Direct-mmapping chunks ----------------------- */ |
2255 | 2255 | ||
2256 | /* |
2256 | /* |
2257 | Directly mmapped chunks are set up with an offset to the start of |
2257 | Directly mmapped chunks are set up with an offset to the start of |
2258 | the mmapped region stored in the prev_foot field of the chunk. This |
2258 | the mmapped region stored in the prev_foot field of the chunk. This |
2259 | allows reconstruction of the required argument to MUNMAP when freed, |
2259 | allows reconstruction of the required argument to MUNMAP when freed, |
2260 | and also allows adjustment of the returned chunk to meet alignment |
2260 | and also allows adjustment of the returned chunk to meet alignment |
2261 | requirements (especially in memalign). |
2261 | requirements (especially in memalign). |
2262 | */ |
2262 | */ |
2263 | 2263 | ||
2264 | /* Malloc using mmap */ |
2264 | /* Malloc using mmap */ |
2265 | static void* mmap_alloc(mstate m, size_t nb) { |
2265 | static void* mmap_alloc(mstate m, size_t nb) { |
2266 | size_t mmsize = mmap_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK); |
2266 | size_t mmsize = mmap_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK); |
2267 | if (m->footprint_limit != 0) { |
2267 | if (m->footprint_limit != 0) { |
2268 | size_t fp = m->footprint + mmsize; |
2268 | size_t fp = m->footprint + mmsize; |
2269 | if (fp <= m->footprint || fp > m->footprint_limit) |
2269 | if (fp <= m->footprint || fp > m->footprint_limit) |
2270 | return 0; |
2270 | return 0; |
2271 | } |
2271 | } |
2272 | if (mmsize > nb) { /* Check for wrap around 0 */ |
2272 | if (mmsize > nb) { /* Check for wrap around 0 */ |
2273 | char* mm = (char*)(CALL_DIRECT_MMAP(mmsize)); |
2273 | char* mm = (char*)(CALL_DIRECT_MMAP(mmsize)); |
2274 | if (mm != CMFAIL) { |
2274 | if (mm != CMFAIL) { |
2275 | size_t offset = align_offset(chunk2mem(mm)); |
2275 | size_t offset = align_offset(chunk2mem(mm)); |
2276 | size_t psize = mmsize - offset - MMAP_FOOT_PAD; |
2276 | size_t psize = mmsize - offset - MMAP_FOOT_PAD; |
2277 | mchunkptr p = (mchunkptr)(mm + offset); |
2277 | mchunkptr p = (mchunkptr)(mm + offset); |
2278 | p->prev_foot = offset; |
2278 | p->prev_foot = offset; |
2279 | p->head = psize; |
2279 | p->head = psize; |
2280 | mark_inuse_foot(m, p, psize); |
2280 | mark_inuse_foot(m, p, psize); |
2281 | chunk_plus_offset(p, psize)->head = FENCEPOST_HEAD; |
2281 | chunk_plus_offset(p, psize)->head = FENCEPOST_HEAD; |
2282 | chunk_plus_offset(p, psize+SIZE_T_SIZE)->head = 0; |
2282 | chunk_plus_offset(p, psize+SIZE_T_SIZE)->head = 0; |
2283 | 2283 | ||
2284 | if (m->least_addr == 0 || mm < m->least_addr) |
2284 | if (m->least_addr == 0 || mm < m->least_addr) |
2285 | m->least_addr = mm; |
2285 | m->least_addr = mm; |
2286 | if ((m->footprint += mmsize) > m->max_footprint) |
2286 | if ((m->footprint += mmsize) > m->max_footprint) |
2287 | m->max_footprint = m->footprint; |
2287 | m->max_footprint = m->footprint; |
2288 | assert(is_aligned(chunk2mem(p))); |
2288 | assert(is_aligned(chunk2mem(p))); |
2289 | check_mmapped_chunk(m, p); |
2289 | check_mmapped_chunk(m, p); |
2290 | return chunk2mem(p); |
2290 | return chunk2mem(p); |
2291 | } |
2291 | } |
2292 | } |
2292 | } |
2293 | return 0; |
2293 | return 0; |
2294 | } |
2294 | } |
2295 | 2295 | ||
2296 | /* Realloc using mmap */ |
2296 | /* Realloc using mmap */ |
2297 | static mchunkptr mmap_resize(mstate m, mchunkptr oldp, size_t nb, int flags) { |
2297 | static mchunkptr mmap_resize(mstate m, mchunkptr oldp, size_t nb, int flags) { |
2298 | size_t oldsize = chunksize(oldp); |
2298 | size_t oldsize = chunksize(oldp); |
2299 | (void)flags; /* placate people compiling -Wunused */ |
2299 | (void)flags; /* placate people compiling -Wunused */ |
2300 | if (is_small(nb)) /* Can't shrink mmap regions below small size */ |
2300 | if (is_small(nb)) /* Can't shrink mmap regions below small size */ |
2301 | return 0; |
2301 | return 0; |
2302 | /* Keep old chunk if big enough but not too big */ |
2302 | /* Keep old chunk if big enough but not too big */ |
2303 | if (oldsize >= nb + SIZE_T_SIZE && |
2303 | if (oldsize >= nb + SIZE_T_SIZE && |
2304 | (oldsize - nb) <= (mparams.granularity << 1)) |
2304 | (oldsize - nb) <= (mparams.granularity << 1)) |
2305 | return oldp; |
2305 | return oldp; |
2306 | else { |
2306 | else { |
2307 | size_t offset = oldp->prev_foot; |
2307 | size_t offset = oldp->prev_foot; |
2308 | size_t oldmmsize = oldsize + offset + MMAP_FOOT_PAD; |
2308 | size_t oldmmsize = oldsize + offset + MMAP_FOOT_PAD; |
2309 | size_t newmmsize = mmap_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK); |
2309 | size_t newmmsize = mmap_align(nb + SIX_SIZE_T_SIZES + CHUNK_ALIGN_MASK); |
2310 | char* cp = (char*)CALL_MREMAP((char*)oldp - offset, |
2310 | char* cp = (char*)CALL_MREMAP((char*)oldp - offset, |
2311 | oldmmsize, newmmsize, flags); |
2311 | oldmmsize, newmmsize, flags); |
2312 | if (cp != CMFAIL) { |
2312 | if (cp != CMFAIL) { |
2313 | mchunkptr newp = (mchunkptr)(cp + offset); |
2313 | mchunkptr newp = (mchunkptr)(cp + offset); |
2314 | size_t psize = newmmsize - offset - MMAP_FOOT_PAD; |
2314 | size_t psize = newmmsize - offset - MMAP_FOOT_PAD; |
2315 | newp->head = psize; |
2315 | newp->head = psize; |
2316 | mark_inuse_foot(m, newp, psize); |
2316 | mark_inuse_foot(m, newp, psize); |
2317 | chunk_plus_offset(newp, psize)->head = FENCEPOST_HEAD; |
2317 | chunk_plus_offset(newp, psize)->head = FENCEPOST_HEAD; |
2318 | chunk_plus_offset(newp, psize+SIZE_T_SIZE)->head = 0; |
2318 | chunk_plus_offset(newp, psize+SIZE_T_SIZE)->head = 0; |
2319 | 2319 | ||
2320 | if (cp < m->least_addr) |
2320 | if (cp < m->least_addr) |
2321 | m->least_addr = cp; |
2321 | m->least_addr = cp; |
2322 | if ((m->footprint += newmmsize - oldmmsize) > m->max_footprint) |
2322 | if ((m->footprint += newmmsize - oldmmsize) > m->max_footprint) |
2323 | m->max_footprint = m->footprint; |
2323 | m->max_footprint = m->footprint; |
2324 | check_mmapped_chunk(m, newp); |
2324 | check_mmapped_chunk(m, newp); |
2325 | return newp; |
2325 | return newp; |
2326 | } |
2326 | } |
2327 | } |
2327 | } |
2328 | return 0; |
2328 | return 0; |
2329 | } |
2329 | } |
2330 | 2330 | ||
2331 | 2331 | ||
2332 | /* -------------------------- mspace management -------------------------- */ |
2332 | /* -------------------------- mspace management -------------------------- */ |
2333 | 2333 | ||
2334 | /* Initialize top chunk and its size */ |
2334 | /* Initialize top chunk and its size */ |
2335 | static void init_top(mstate m, mchunkptr p, size_t psize) { |
2335 | static void init_top(mstate m, mchunkptr p, size_t psize) { |
2336 | /* Ensure alignment */ |
2336 | /* Ensure alignment */ |
2337 | size_t offset = align_offset(chunk2mem(p)); |
2337 | size_t offset = align_offset(chunk2mem(p)); |
2338 | p = (mchunkptr)((char*)p + offset); |
2338 | p = (mchunkptr)((char*)p + offset); |
2339 | psize -= offset; |
2339 | psize -= offset; |
2340 | 2340 | ||
2341 | m->top = p; |
2341 | m->top = p; |
2342 | m->topsize = psize; |
2342 | m->topsize = psize; |
2343 | p->head = psize | PINUSE_BIT; |
2343 | p->head = psize | PINUSE_BIT; |
2344 | /* set size of fake trailing chunk holding overhead space only once */ |
2344 | /* set size of fake trailing chunk holding overhead space only once */ |
2345 | chunk_plus_offset(p, psize)->head = TOP_FOOT_SIZE; |
2345 | chunk_plus_offset(p, psize)->head = TOP_FOOT_SIZE; |
2346 | m->trim_check = mparams.trim_threshold; /* reset on each update */ |
2346 | m->trim_check = mparams.trim_threshold; /* reset on each update */ |
2347 | } |
2347 | } |
2348 | 2348 | ||
2349 | /* Initialize bins for a new mstate that is otherwise zeroed out */ |
2349 | /* Initialize bins for a new mstate that is otherwise zeroed out */ |
2350 | static void init_bins(mstate m) { |
2350 | static void init_bins(mstate m) { |
2351 | /* Establish circular links for smallbins */ |
2351 | /* Establish circular links for smallbins */ |
2352 | bindex_t i; |
2352 | bindex_t i; |
2353 | for (i = 0; i < NSMALLBINS; ++i) { |
2353 | for (i = 0; i < NSMALLBINS; ++i) { |
2354 | sbinptr bin = smallbin_at(m,i); |
2354 | sbinptr bin = smallbin_at(m,i); |
2355 | bin->fd = bin->bk = bin; |
2355 | bin->fd = bin->bk = bin; |
2356 | } |
2356 | } |
2357 | } |
2357 | } |
2358 | 2358 | ||
2359 | /* Allocate chunk and prepend remainder with chunk in successor base. */ |
2359 | /* Allocate chunk and prepend remainder with chunk in successor base. */ |
2360 | static void* prepend_alloc(mstate m, char* newbase, char* oldbase, |
2360 | static void* prepend_alloc(mstate m, char* newbase, char* oldbase, |
2361 | size_t nb) { |
2361 | size_t nb) { |
2362 | mchunkptr p = align_as_chunk(newbase); |
2362 | mchunkptr p = align_as_chunk(newbase); |
2363 | mchunkptr oldfirst = align_as_chunk(oldbase); |
2363 | mchunkptr oldfirst = align_as_chunk(oldbase); |
2364 | size_t psize = (char*)oldfirst - (char*)p; |
2364 | size_t psize = (char*)oldfirst - (char*)p; |
2365 | mchunkptr q = chunk_plus_offset(p, nb); |
2365 | mchunkptr q = chunk_plus_offset(p, nb); |
2366 | size_t qsize = psize - nb; |
2366 | size_t qsize = psize - nb; |
2367 | set_size_and_pinuse_of_inuse_chunk(m, p, nb); |
2367 | set_size_and_pinuse_of_inuse_chunk(m, p, nb); |
2368 | 2368 | ||
2369 | assert((char*)oldfirst > (char*)q); |
2369 | assert((char*)oldfirst > (char*)q); |
2370 | assert(pinuse(oldfirst)); |
2370 | assert(pinuse(oldfirst)); |
2371 | assert(qsize >= MIN_CHUNK_SIZE); |
2371 | assert(qsize >= MIN_CHUNK_SIZE); |
2372 | 2372 | ||
2373 | /* consolidate remainder with first chunk of old base */ |
2373 | /* consolidate remainder with first chunk of old base */ |
2374 | if (oldfirst == m->top) { |
2374 | if (oldfirst == m->top) { |
2375 | size_t tsize = m->topsize += qsize; |
2375 | size_t tsize = m->topsize += qsize; |
2376 | m->top = q; |
2376 | m->top = q; |
2377 | q->head = tsize | PINUSE_BIT; |
2377 | q->head = tsize | PINUSE_BIT; |
2378 | check_top_chunk(m, q); |
2378 | check_top_chunk(m, q); |
2379 | } |
2379 | } |
2380 | else if (oldfirst == m->dv) { |
2380 | else if (oldfirst == m->dv) { |
2381 | size_t dsize = m->dvsize += qsize; |
2381 | size_t dsize = m->dvsize += qsize; |
2382 | m->dv = q; |
2382 | m->dv = q; |
2383 | set_size_and_pinuse_of_free_chunk(q, dsize); |
2383 | set_size_and_pinuse_of_free_chunk(q, dsize); |
2384 | } |
2384 | } |
2385 | else { |
2385 | else { |
2386 | if (!is_inuse(oldfirst)) { |
2386 | if (!is_inuse(oldfirst)) { |
2387 | size_t nsize = chunksize(oldfirst); |
2387 | size_t nsize = chunksize(oldfirst); |
2388 | unlink_chunk(m, oldfirst, nsize); |
2388 | unlink_chunk(m, oldfirst, nsize); |
2389 | oldfirst = chunk_plus_offset(oldfirst, nsize); |
2389 | oldfirst = chunk_plus_offset(oldfirst, nsize); |
2390 | qsize += nsize; |
2390 | qsize += nsize; |
2391 | } |
2391 | } |
2392 | set_free_with_pinuse(q, qsize, oldfirst); |
2392 | set_free_with_pinuse(q, qsize, oldfirst); |
2393 | insert_chunk(m, q, qsize); |
2393 | insert_chunk(m, q, qsize); |
2394 | check_free_chunk(m, q); |
2394 | check_free_chunk(m, q); |
2395 | } |
2395 | } |
2396 | 2396 | ||
2397 | check_malloced_chunk(m, chunk2mem(p), nb); |
2397 | check_malloced_chunk(m, chunk2mem(p), nb); |
2398 | return chunk2mem(p); |
2398 | return chunk2mem(p); |
2399 | } |
2399 | } |
2400 | 2400 | ||
2401 | /* Add a segment to hold a new noncontiguous region */ |
2401 | /* Add a segment to hold a new noncontiguous region */ |
2402 | static void add_segment(mstate m, char* tbase, size_t tsize, flag_t mmapped) { |
2402 | static void add_segment(mstate m, char* tbase, size_t tsize, flag_t mmapped) { |
2403 | /* Determine locations and sizes of segment, fenceposts, old top */ |
2403 | /* Determine locations and sizes of segment, fenceposts, old top */ |
2404 | char* old_top = (char*)m->top; |
2404 | char* old_top = (char*)m->top; |
2405 | msegmentptr oldsp = segment_holding(m, old_top); |
2405 | msegmentptr oldsp = segment_holding(m, old_top); |
2406 | char* old_end = oldsp->base + oldsp->size; |
2406 | char* old_end = oldsp->base + oldsp->size; |
2407 | size_t ssize = pad_request(sizeof(struct malloc_segment)); |
2407 | size_t ssize = pad_request(sizeof(struct malloc_segment)); |
2408 | char* rawsp = old_end - (ssize + FOUR_SIZE_T_SIZES + CHUNK_ALIGN_MASK); |
2408 | char* rawsp = old_end - (ssize + FOUR_SIZE_T_SIZES + CHUNK_ALIGN_MASK); |
2409 | size_t offset = align_offset(chunk2mem(rawsp)); |
2409 | size_t offset = align_offset(chunk2mem(rawsp)); |
2410 | char* asp = rawsp + offset; |
2410 | char* asp = rawsp + offset; |
2411 | char* csp = (asp < (old_top + MIN_CHUNK_SIZE))? old_top : asp; |
2411 | char* csp = (asp < (old_top + MIN_CHUNK_SIZE))? old_top : asp; |
2412 | mchunkptr sp = (mchunkptr)csp; |
2412 | mchunkptr sp = (mchunkptr)csp; |
2413 | msegmentptr ss = (msegmentptr)(chunk2mem(sp)); |
2413 | msegmentptr ss = (msegmentptr)(chunk2mem(sp)); |
2414 | mchunkptr tnext = chunk_plus_offset(sp, ssize); |
2414 | mchunkptr tnext = chunk_plus_offset(sp, ssize); |
2415 | mchunkptr p = tnext; |
2415 | mchunkptr p = tnext; |
2416 | int nfences = 0; |
2416 | int nfences = 0; |
2417 | 2417 | ||
2418 | /* reset top to new space */ |
2418 | /* reset top to new space */ |
2419 | init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); |
2419 | init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); |
2420 | 2420 | ||
2421 | /* Set up segment record */ |
2421 | /* Set up segment record */ |
2422 | assert(is_aligned(ss)); |
2422 | assert(is_aligned(ss)); |
2423 | set_size_and_pinuse_of_inuse_chunk(m, sp, ssize); |
2423 | set_size_and_pinuse_of_inuse_chunk(m, sp, ssize); |
2424 | *ss = m->seg; /* Push current record */ |
2424 | *ss = m->seg; /* Push current record */ |
2425 | m->seg.base = tbase; |
2425 | m->seg.base = tbase; |
2426 | m->seg.size = tsize; |
2426 | m->seg.size = tsize; |
2427 | m->seg.sflags = mmapped; |
2427 | m->seg.sflags = mmapped; |
2428 | m->seg.next = ss; |
2428 | m->seg.next = ss; |
2429 | 2429 | ||
2430 | /* Insert trailing fenceposts */ |
2430 | /* Insert trailing fenceposts */ |
2431 | for (;;) { |
2431 | for (;;) { |
2432 | mchunkptr nextp = chunk_plus_offset(p, SIZE_T_SIZE); |
2432 | mchunkptr nextp = chunk_plus_offset(p, SIZE_T_SIZE); |
2433 | p->head = FENCEPOST_HEAD; |
2433 | p->head = FENCEPOST_HEAD; |
2434 | ++nfences; |
2434 | ++nfences; |
2435 | if ((char*)(&(nextp->head)) < old_end) |
2435 | if ((char*)(&(nextp->head)) < old_end) |
2436 | p = nextp; |
2436 | p = nextp; |
2437 | else |
2437 | else |
2438 | break; |
2438 | break; |
2439 | } |
2439 | } |
2440 | assert(nfences >= 2); |
2440 | assert(nfences >= 2); |
2441 | 2441 | ||
2442 | /* Insert the rest of old top into a bin as an ordinary free chunk */ |
2442 | /* Insert the rest of old top into a bin as an ordinary free chunk */ |
2443 | if (csp != old_top) { |
2443 | if (csp != old_top) { |
2444 | mchunkptr q = (mchunkptr)old_top; |
2444 | mchunkptr q = (mchunkptr)old_top; |
2445 | size_t psize = csp - old_top; |
2445 | size_t psize = csp - old_top; |
2446 | mchunkptr tn = chunk_plus_offset(q, psize); |
2446 | mchunkptr tn = chunk_plus_offset(q, psize); |
2447 | set_free_with_pinuse(q, psize, tn); |
2447 | set_free_with_pinuse(q, psize, tn); |
2448 | insert_chunk(m, q, psize); |
2448 | insert_chunk(m, q, psize); |
2449 | } |
2449 | } |
2450 | 2450 | ||
2451 | check_top_chunk(m, m->top); |
2451 | check_top_chunk(m, m->top); |
2452 | } |
2452 | } |
2453 | 2453 | ||
2454 | /* -------------------------- System allocation -------------------------- */ |
2454 | /* -------------------------- System allocation -------------------------- */ |
2455 | 2455 | ||
2456 | /* Get memory from system using MORECORE or MMAP */ |
2456 | /* Get memory from system using MORECORE or MMAP */ |
2457 | static void* sys_alloc(mstate m, size_t nb) { |
2457 | static void* sys_alloc(mstate m, size_t nb) { |
2458 | char* tbase = CMFAIL; |
2458 | char* tbase = CMFAIL; |
2459 | size_t tsize = 0; |
2459 | size_t tsize = 0; |
2460 | flag_t mmap_flag = 0; |
2460 | flag_t mmap_flag = 0; |
2461 | size_t asize; /* allocation size */ |
2461 | size_t asize; /* allocation size */ |
2462 | 2462 | ||
2463 | ensure_initialization(); |
2463 | ensure_initialization(); |
2464 | 2464 | ||
2465 | printf("%s %d bytes\n", __FUNCTION__, nb); |
2465 | printf("%s %d bytes\n", __FUNCTION__, nb); |
2466 | 2466 | ||
2467 | /* Directly map large chunks, but only if already initialized */ |
2467 | /* Directly map large chunks, but only if already initialized */ |
2468 | if (use_mmap(m) && nb >= mparams.mmap_threshold && m->topsize != 0) { |
2468 | if (use_mmap(m) && nb >= mparams.mmap_threshold && m->topsize != 0) { |
2469 | void* mem = mmap_alloc(m, nb); |
2469 | void* mem = mmap_alloc(m, nb); |
2470 | if (mem != 0) |
2470 | if (mem != 0) |
2471 | return mem; |
2471 | return mem; |
2472 | } |
2472 | } |
2473 | 2473 | ||
2474 | asize = granularity_align(nb + SYS_ALLOC_PADDING); |
2474 | asize = granularity_align(nb + SYS_ALLOC_PADDING); |
2475 | if (asize <= nb) |
2475 | if (asize <= nb) |
2476 | return 0; /* wraparound */ |
2476 | return 0; /* wraparound */ |
2477 | if (m->footprint_limit != 0) { |
2477 | if (m->footprint_limit != 0) { |
2478 | size_t fp = m->footprint + asize; |
2478 | size_t fp = m->footprint + asize; |
2479 | if (fp <= m->footprint || fp > m->footprint_limit) |
2479 | if (fp <= m->footprint || fp > m->footprint_limit) |
2480 | return 0; |
2480 | return 0; |
2481 | } |
2481 | } |
2482 | 2482 | ||
2483 | /* |
2483 | /* |
2484 | Try getting memory in any of three ways (in most-preferred to |
2484 | Try getting memory in any of three ways (in most-preferred to |
2485 | least-preferred order): |
2485 | least-preferred order): |
2486 | 1. A call to MORECORE that can normally contiguously extend memory. |
2486 | 1. A call to MORECORE that can normally contiguously extend memory. |
2487 | (disabled if not MORECORE_CONTIGUOUS or not HAVE_MORECORE or |
2487 | (disabled if not MORECORE_CONTIGUOUS or not HAVE_MORECORE or |
2488 | or main space is mmapped or a previous contiguous call failed) |
2488 | or main space is mmapped or a previous contiguous call failed) |
2489 | 2. A call to MMAP new space (disabled if not HAVE_MMAP). |
2489 | 2. A call to MMAP new space (disabled if not HAVE_MMAP). |
2490 | Note that under the default settings, if MORECORE is unable to |
2490 | Note that under the default settings, if MORECORE is unable to |
2491 | fulfill a request, and HAVE_MMAP is true, then mmap is |
2491 | fulfill a request, and HAVE_MMAP is true, then mmap is |
2492 | used as a noncontiguous system allocator. This is a useful backup |
2492 | used as a noncontiguous system allocator. This is a useful backup |
2493 | strategy for systems with holes in address spaces -- in this case |
2493 | strategy for systems with holes in address spaces -- in this case |
2494 | sbrk cannot contiguously expand the heap, but mmap may be able to |
2494 | sbrk cannot contiguously expand the heap, but mmap may be able to |
2495 | find space. |
2495 | find space. |
2496 | 3. A call to MORECORE that cannot usually contiguously extend memory. |
2496 | 3. A call to MORECORE that cannot usually contiguously extend memory. |
2497 | (disabled if not HAVE_MORECORE) |
2497 | (disabled if not HAVE_MORECORE) |
2498 | 2498 | ||
2499 | In all cases, we need to request enough bytes from system to ensure |
2499 | In all cases, we need to request enough bytes from system to ensure |
2500 | we can malloc nb bytes upon success, so pad with enough space for |
2500 | we can malloc nb bytes upon success, so pad with enough space for |
2501 | top_foot, plus alignment-pad to make sure we don't lose bytes if |
2501 | top_foot, plus alignment-pad to make sure we don't lose bytes if |
2502 | not on boundary, and round this up to a granularity unit. |
2502 | not on boundary, and round this up to a granularity unit. |
2503 | */ |
2503 | */ |
2504 | 2504 | ||
2505 | #if 0 |
2505 | #if 0 |
2506 | if (MORECORE_CONTIGUOUS && !use_noncontiguous(m)) { |
2506 | if (MORECORE_CONTIGUOUS && !use_noncontiguous(m)) { |
2507 | char* br = CMFAIL; |
2507 | char* br = CMFAIL; |
2508 | size_t ssize = asize; /* sbrk call size */ |
2508 | size_t ssize = asize; /* sbrk call size */ |
2509 | msegmentptr ss = (m->top == 0)? 0 : segment_holding(m, (char*)m->top); |
2509 | msegmentptr ss = (m->top == 0)? 0 : segment_holding(m, (char*)m->top); |
2510 | ACQUIRE_MALLOC_GLOBAL_LOCK(); |
2510 | ACQUIRE_MALLOC_GLOBAL_LOCK(); |
2511 | 2511 | ||
2512 | if (ss == 0) { /* First time through or recovery */ |
2512 | if (ss == 0) { /* First time through or recovery */ |
2513 | char* base = (char*)CALL_MORECORE(0); |
2513 | char* base = (char*)CALL_MORECORE(0); |
2514 | if (base != CMFAIL) { |
2514 | if (base != CMFAIL) { |
2515 | size_t fp; |
2515 | size_t fp; |
2516 | /* Adjust to end on a page boundary */ |
2516 | /* Adjust to end on a page boundary */ |
2517 | if (!is_page_aligned(base)) |
2517 | if (!is_page_aligned(base)) |
2518 | ssize += (page_align((size_t)base) - (size_t)base); |
2518 | ssize += (page_align((size_t)base) - (size_t)base); |
2519 | fp = m->footprint + ssize; /* recheck limits */ |
2519 | fp = m->footprint + ssize; /* recheck limits */ |
2520 | if (ssize > nb && ssize < HALF_MAX_SIZE_T && |
2520 | if (ssize > nb && ssize < HALF_MAX_SIZE_T && |
2521 | (m->footprint_limit == 0 || |
2521 | (m->footprint_limit == 0 || |
2522 | (fp > m->footprint && fp <= m->footprint_limit)) && |
2522 | (fp > m->footprint && fp <= m->footprint_limit)) && |
2523 | (br = (char*)(CALL_MORECORE(ssize))) == base) { |
2523 | (br = (char*)(CALL_MORECORE(ssize))) == base) { |
2524 | tbase = base; |
2524 | tbase = base; |
2525 | tsize = ssize; |
2525 | tsize = ssize; |
2526 | } |
2526 | } |
2527 | } |
2527 | } |
2528 | } |
2528 | } |
2529 | else { |
2529 | else { |
2530 | /* Subtract out existing available top space from MORECORE request. */ |
2530 | /* Subtract out existing available top space from MORECORE request. */ |
2531 | ssize = granularity_align(nb - m->topsize + SYS_ALLOC_PADDING); |
2531 | ssize = granularity_align(nb - m->topsize + SYS_ALLOC_PADDING); |
2532 | /* Use mem here only if it did continuously extend old space */ |
2532 | /* Use mem here only if it did continuously extend old space */ |
2533 | if (ssize < HALF_MAX_SIZE_T && |
2533 | if (ssize < HALF_MAX_SIZE_T && |
2534 | (br = (char*)(CALL_MORECORE(ssize))) == ss->base+ss->size) { |
2534 | (br = (char*)(CALL_MORECORE(ssize))) == ss->base+ss->size) { |
2535 | tbase = br; |
2535 | tbase = br; |
2536 | tsize = ssize; |
2536 | tsize = ssize; |
2537 | } |
2537 | } |
2538 | } |
2538 | } |
2539 | 2539 | ||
2540 | if (tbase == CMFAIL) { /* Cope with partial failure */ |
2540 | if (tbase == CMFAIL) { /* Cope with partial failure */ |
2541 | if (br != CMFAIL) { /* Try to use/extend the space we did get */ |
2541 | if (br != CMFAIL) { /* Try to use/extend the space we did get */ |
2542 | if (ssize < HALF_MAX_SIZE_T && |
2542 | if (ssize < HALF_MAX_SIZE_T && |
2543 | ssize < nb + SYS_ALLOC_PADDING) { |
2543 | ssize < nb + SYS_ALLOC_PADDING) { |
2544 | size_t esize = granularity_align(nb + SYS_ALLOC_PADDING - ssize); |
2544 | size_t esize = granularity_align(nb + SYS_ALLOC_PADDING - ssize); |
2545 | if (esize < HALF_MAX_SIZE_T) { |
2545 | if (esize < HALF_MAX_SIZE_T) { |
2546 | char* end = (char*)CALL_MORECORE(esize); |
2546 | char* end = (char*)CALL_MORECORE(esize); |
2547 | if (end != CMFAIL) |
2547 | if (end != CMFAIL) |
2548 | ssize += esize; |
2548 | ssize += esize; |
2549 | else { /* Can't use; try to release */ |
2549 | else { /* Can't use; try to release */ |
2550 | (void) CALL_MORECORE(-ssize); |
2550 | (void) CALL_MORECORE(-ssize); |
2551 | br = CMFAIL; |
2551 | br = CMFAIL; |
2552 | } |
2552 | } |
2553 | } |
2553 | } |
2554 | } |
2554 | } |
2555 | } |
2555 | } |
2556 | if (br != CMFAIL) { /* Use the space we did get */ |
2556 | if (br != CMFAIL) { /* Use the space we did get */ |
2557 | tbase = br; |
2557 | tbase = br; |
2558 | tsize = ssize; |
2558 | tsize = ssize; |
2559 | } |
2559 | } |
2560 | else |
2560 | else |
2561 | disable_contiguous(m); /* Don't try contiguous path in the future */ |
2561 | disable_contiguous(m); /* Don't try contiguous path in the future */ |
2562 | } |
2562 | } |
2563 | 2563 | ||
2564 | RELEASE_MALLOC_GLOBAL_LOCK(); |
2564 | RELEASE_MALLOC_GLOBAL_LOCK(); |
2565 | } |
2565 | } |
2566 | #endif |
2566 | #endif |
2567 | 2567 | ||
2568 | if (HAVE_MMAP && tbase == CMFAIL) { /* Try MMAP */ |
2568 | if (HAVE_MMAP && tbase == CMFAIL) { /* Try MMAP */ |
2569 | char* mp = (char*)(CALL_MMAP(asize)); |
2569 | char* mp = (char*)(CALL_MMAP(asize)); |
2570 | if (mp != CMFAIL) { |
2570 | if (mp != CMFAIL) { |
2571 | tbase = mp; |
2571 | tbase = mp; |
2572 | tsize = asize; |
2572 | tsize = asize; |
2573 | mmap_flag = USE_MMAP_BIT; |
2573 | mmap_flag = USE_MMAP_BIT; |
2574 | } |
2574 | } |
2575 | } |
2575 | } |
2576 | 2576 | ||
2577 | #if 0 |
2577 | #if 0 |
2578 | if (HAVE_MORECORE && tbase == CMFAIL) { /* Try noncontiguous MORECORE */ |
2578 | if (HAVE_MORECORE && tbase == CMFAIL) { /* Try noncontiguous MORECORE */ |
2579 | if (asize < HALF_MAX_SIZE_T) { |
2579 | if (asize < HALF_MAX_SIZE_T) { |
2580 | char* br = CMFAIL; |
2580 | char* br = CMFAIL; |
2581 | char* end = CMFAIL; |
2581 | char* end = CMFAIL; |
2582 | ACQUIRE_MALLOC_GLOBAL_LOCK(); |
2582 | ACQUIRE_MALLOC_GLOBAL_LOCK(); |
2583 | br = (char*)(CALL_MORECORE(asize)); |
2583 | br = (char*)(CALL_MORECORE(asize)); |
2584 | end = (char*)(CALL_MORECORE(0)); |
2584 | end = (char*)(CALL_MORECORE(0)); |
2585 | RELEASE_MALLOC_GLOBAL_LOCK(); |
2585 | RELEASE_MALLOC_GLOBAL_LOCK(); |
2586 | if (br != CMFAIL && end != CMFAIL && br < end) { |
2586 | if (br != CMFAIL && end != CMFAIL && br < end) { |
2587 | size_t ssize = end - br; |
2587 | size_t ssize = end - br; |
2588 | if (ssize > nb + TOP_FOOT_SIZE) { |
2588 | if (ssize > nb + TOP_FOOT_SIZE) { |
2589 | tbase = br; |
2589 | tbase = br; |
2590 | tsize = ssize; |
2590 | tsize = ssize; |
2591 | } |
2591 | } |
2592 | } |
2592 | } |
2593 | } |
2593 | } |
2594 | } |
2594 | } |
2595 | #endif |
2595 | #endif |
2596 | 2596 | ||
2597 | if (tbase != CMFAIL) { |
2597 | if (tbase != CMFAIL) { |
2598 | 2598 | ||
2599 | if ((m->footprint += tsize) > m->max_footprint) |
2599 | if ((m->footprint += tsize) > m->max_footprint) |
2600 | m->max_footprint = m->footprint; |
2600 | m->max_footprint = m->footprint; |
2601 | 2601 | ||
2602 | if (!is_initialized(m)) { /* first-time initialization */ |
2602 | if (!is_initialized(m)) { /* first-time initialization */ |
2603 | if (m->least_addr == 0 || tbase < m->least_addr) |
2603 | if (m->least_addr == 0 || tbase < m->least_addr) |
2604 | m->least_addr = tbase; |
2604 | m->least_addr = tbase; |
2605 | m->seg.base = tbase; |
2605 | m->seg.base = tbase; |
2606 | m->seg.size = tsize; |
2606 | m->seg.size = tsize; |
2607 | m->seg.sflags = mmap_flag; |
2607 | m->seg.sflags = mmap_flag; |
2608 | m->magic = mparams.magic; |
2608 | m->magic = mparams.magic; |
2609 | m->release_checks = MAX_RELEASE_CHECK_RATE; |
2609 | m->release_checks = MAX_RELEASE_CHECK_RATE; |
2610 | init_bins(m); |
2610 | init_bins(m); |
2611 | 2611 | ||
2612 | if (is_global(m)) |
2612 | if (is_global(m)) |
2613 | init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); |
2613 | init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE); |
2614 | else |
2614 | else |
2615 | { |
2615 | { |
2616 | /* Offset top by embedded malloc_state */ |
2616 | /* Offset top by embedded malloc_state */ |
2617 | mchunkptr mn = next_chunk(mem2chunk(m)); |
2617 | mchunkptr mn = next_chunk(mem2chunk(m)); |
2618 | init_top(m, mn, (size_t)((tbase + tsize) - (char*)mn) -TOP_FOOT_SIZE); |
2618 | init_top(m, mn, (size_t)((tbase + tsize) - (char*)mn) -TOP_FOOT_SIZE); |
2619 | } |
2619 | } |
2620 | } |
2620 | } |
2621 | 2621 | ||
2622 | else { |
2622 | else { |
2623 | /* Try to merge with an existing segment */ |
2623 | /* Try to merge with an existing segment */ |
2624 | msegmentptr sp = &m->seg; |
2624 | msegmentptr sp = &m->seg; |
2625 | /* Only consider most recent segment if traversal suppressed */ |
2625 | /* Only consider most recent segment if traversal suppressed */ |
2626 | while (sp != 0 && tbase != sp->base + sp->size) |
2626 | while (sp != 0 && tbase != sp->base + sp->size) |
2627 | sp = (NO_SEGMENT_TRAVERSAL) ? 0 : sp->next; |
2627 | sp = (NO_SEGMENT_TRAVERSAL) ? 0 : sp->next; |
2628 | if (sp != 0 && |
2628 | if (sp != 0 && |
2629 | !is_extern_segment(sp) && |
2629 | !is_extern_segment(sp) && |
2630 | (sp->sflags & USE_MMAP_BIT) == mmap_flag && |
2630 | (sp->sflags & USE_MMAP_BIT) == mmap_flag && |
2631 | segment_holds(sp, m->top)) { /* append */ |
2631 | segment_holds(sp, m->top)) { /* append */ |
2632 | sp->size += tsize; |
2632 | sp->size += tsize; |
2633 | init_top(m, m->top, m->topsize + tsize); |
2633 | init_top(m, m->top, m->topsize + tsize); |
2634 | } |
2634 | } |
2635 | else { |
2635 | else { |
2636 | if (tbase < m->least_addr) |
2636 | if (tbase < m->least_addr) |
2637 | m->least_addr = tbase; |
2637 | m->least_addr = tbase; |
2638 | sp = &m->seg; |
2638 | sp = &m->seg; |
2639 | while (sp != 0 && sp->base != tbase + tsize) |
2639 | while (sp != 0 && sp->base != tbase + tsize) |
2640 | sp = (NO_SEGMENT_TRAVERSAL) ? 0 : sp->next; |
2640 | sp = (NO_SEGMENT_TRAVERSAL) ? 0 : sp->next; |
2641 | if (sp != 0 && |
2641 | if (sp != 0 && |
2642 | !is_extern_segment(sp) && |
2642 | !is_extern_segment(sp) && |
2643 | (sp->sflags & USE_MMAP_BIT) == mmap_flag) { |
2643 | (sp->sflags & USE_MMAP_BIT) == mmap_flag) { |
2644 | char* oldbase = sp->base; |
2644 | char* oldbase = sp->base; |
2645 | sp->base = tbase; |
2645 | sp->base = tbase; |
2646 | sp->size += tsize; |
2646 | sp->size += tsize; |
2647 | return prepend_alloc(m, tbase, oldbase, nb); |
2647 | return prepend_alloc(m, tbase, oldbase, nb); |
2648 | } |
2648 | } |
2649 | else |
2649 | else |
2650 | add_segment(m, tbase, tsize, mmap_flag); |
2650 | add_segment(m, tbase, tsize, mmap_flag); |
2651 | } |
2651 | } |
2652 | } |
2652 | } |
2653 | 2653 | ||
2654 | if (nb < m->topsize) { /* Allocate from new or extended top space */ |
2654 | if (nb < m->topsize) { /* Allocate from new or extended top space */ |
2655 | size_t rsize = m->topsize -= nb; |
2655 | size_t rsize = m->topsize -= nb; |
2656 | mchunkptr p = m->top; |
2656 | mchunkptr p = m->top; |
2657 | mchunkptr r = m->top = chunk_plus_offset(p, nb); |
2657 | mchunkptr r = m->top = chunk_plus_offset(p, nb); |
2658 | r->head = rsize | PINUSE_BIT; |
2658 | r->head = rsize | PINUSE_BIT; |
2659 | set_size_and_pinuse_of_inuse_chunk(m, p, nb); |
2659 | set_size_and_pinuse_of_inuse_chunk(m, p, nb); |
2660 | check_top_chunk(m, m->top); |
2660 | check_top_chunk(m, m->top); |
2661 | check_malloced_chunk(m, chunk2mem(p), nb); |
2661 | check_malloced_chunk(m, chunk2mem(p), nb); |
2662 | return chunk2mem(p); |
2662 | return chunk2mem(p); |
2663 | } |
2663 | } |
2664 | } |
2664 | } |
2665 | 2665 | ||
2666 | // MALLOC_FAILURE_ACTION; |
2666 | // MALLOC_FAILURE_ACTION; |
2667 | return 0; |
2667 | return 0; |
2668 | } |
2668 | } |
2669 | 2669 | ||
2670 | /* ----------------------- system deallocation -------------------------- */ |
2670 | /* ----------------------- system deallocation -------------------------- */ |
2671 | 2671 | ||
2672 | /* Unmap and unlink any mmapped segments that don't contain used chunks */ |
2672 | /* Unmap and unlink any mmapped segments that don't contain used chunks */ |
2673 | static size_t release_unused_segments(mstate m) { |
2673 | static size_t release_unused_segments(mstate m) { |
2674 | size_t released = 0; |
2674 | size_t released = 0; |
2675 | int nsegs = 0; |
2675 | int nsegs = 0; |
2676 | msegmentptr pred = &m->seg; |
2676 | msegmentptr pred = &m->seg; |
2677 | msegmentptr sp = pred->next; |
2677 | msegmentptr sp = pred->next; |
2678 | while (sp != 0) { |
2678 | while (sp != 0) { |
2679 | char* base = sp->base; |
2679 | char* base = sp->base; |
2680 | size_t size = sp->size; |
2680 | size_t size = sp->size; |
2681 | msegmentptr next = sp->next; |
2681 | msegmentptr next = sp->next; |
2682 | ++nsegs; |
2682 | ++nsegs; |
2683 | if (is_mmapped_segment(sp) && !is_extern_segment(sp)) { |
2683 | if (is_mmapped_segment(sp) && !is_extern_segment(sp)) { |
2684 | mchunkptr p = align_as_chunk(base); |
2684 | mchunkptr p = align_as_chunk(base); |
2685 | size_t psize = chunksize(p); |
2685 | size_t psize = chunksize(p); |
2686 | /* Can unmap if first chunk holds entire segment and not pinned */ |
2686 | /* Can unmap if first chunk holds entire segment and not pinned */ |
2687 | if (!is_inuse(p) && (char*)p + psize >= base + size - TOP_FOOT_SIZE) { |
2687 | if (!is_inuse(p) && (char*)p + psize >= base + size - TOP_FOOT_SIZE) { |
2688 | tchunkptr tp = (tchunkptr)p; |
2688 | tchunkptr tp = (tchunkptr)p; |
2689 | assert(segment_holds(sp, (char*)sp)); |
2689 | assert(segment_holds(sp, (char*)sp)); |
2690 | if (p == m->dv) { |
2690 | if (p == m->dv) { |
2691 | m->dv = 0; |
2691 | m->dv = 0; |
2692 | m->dvsize = 0; |
2692 | m->dvsize = 0; |
2693 | } |
2693 | } |
2694 | else { |
2694 | else { |
2695 | unlink_large_chunk(m, tp); |
2695 | unlink_large_chunk(m, tp); |
2696 | } |
2696 | } |
2697 | if (CALL_MUNMAP(base, size) == 0) { |
2697 | if (CALL_MUNMAP(base, size) == 0) { |
2698 | released += size; |
2698 | released += size; |
2699 | m->footprint -= size; |
2699 | m->footprint -= size; |
2700 | /* unlink obsoleted record */ |
2700 | /* unlink obsoleted record */ |
2701 | sp = pred; |
2701 | sp = pred; |
2702 | sp->next = next; |
2702 | sp->next = next; |
2703 | } |
2703 | } |
2704 | else { /* back out if cannot unmap */ |
2704 | else { /* back out if cannot unmap */ |
2705 | insert_large_chunk(m, tp, psize); |
2705 | insert_large_chunk(m, tp, psize); |
2706 | } |
2706 | } |
2707 | } |
2707 | } |
2708 | } |
2708 | } |
2709 | if (NO_SEGMENT_TRAVERSAL) /* scan only first segment */ |
2709 | if (NO_SEGMENT_TRAVERSAL) /* scan only first segment */ |
2710 | break; |
2710 | break; |
2711 | pred = sp; |
2711 | pred = sp; |
2712 | sp = next; |
2712 | sp = next; |
2713 | } |
2713 | } |
2714 | /* Reset check counter */ |
2714 | /* Reset check counter */ |
2715 | m->release_checks = (((size_t) nsegs > (size_t) MAX_RELEASE_CHECK_RATE)? |
2715 | m->release_checks = (((size_t) nsegs > (size_t) MAX_RELEASE_CHECK_RATE)? |
2716 | (size_t) nsegs : (size_t) MAX_RELEASE_CHECK_RATE); |
2716 | (size_t) nsegs : (size_t) MAX_RELEASE_CHECK_RATE); |
2717 | return released; |
2717 | return released; |
2718 | } |
2718 | } |
2719 | 2719 | ||
2720 | static int sys_trim(mstate m, size_t pad) { |
2720 | static int sys_trim(mstate m, size_t pad) { |
2721 | size_t released = 0; |
2721 | size_t released = 0; |
2722 | ensure_initialization(); |
2722 | ensure_initialization(); |
2723 | if (pad < MAX_REQUEST && is_initialized(m)) { |
2723 | if (pad < MAX_REQUEST && is_initialized(m)) { |
2724 | pad += TOP_FOOT_SIZE; /* ensure enough room for segment overhead */ |
2724 | pad += TOP_FOOT_SIZE; /* ensure enough room for segment overhead */ |
2725 | 2725 | ||
2726 | if (m->topsize > pad) { |
2726 | if (m->topsize > pad) { |
2727 | /* Shrink top space in granularity-size units, keeping at least one */ |
2727 | /* Shrink top space in granularity-size units, keeping at least one */ |
2728 | size_t unit = mparams.granularity; |
2728 | size_t unit = mparams.granularity; |
2729 | size_t extra = ((m->topsize - pad + (unit - SIZE_T_ONE)) / unit - |
2729 | size_t extra = ((m->topsize - pad + (unit - SIZE_T_ONE)) / unit - |
2730 | SIZE_T_ONE) * unit; |
2730 | SIZE_T_ONE) * unit; |
2731 | msegmentptr sp = segment_holding(m, (char*)m->top); |
2731 | msegmentptr sp = segment_holding(m, (char*)m->top); |
2732 | 2732 | ||
2733 | if (!is_extern_segment(sp)) { |
2733 | if (!is_extern_segment(sp)) { |
2734 | if (is_mmapped_segment(sp)) { |
2734 | if (is_mmapped_segment(sp)) { |
2735 | if (HAVE_MMAP && |
2735 | if (HAVE_MMAP && |
2736 | sp->size >= extra && |
2736 | sp->size >= extra && |
2737 | !has_segment_link(m, sp)) { /* can't shrink if pinned */ |
2737 | !has_segment_link(m, sp)) { /* can't shrink if pinned */ |
2738 | size_t newsize = sp->size - extra; |
2738 | size_t newsize = sp->size - extra; |
2739 | (void)newsize; /* placate people compiling -Wunused-variable */ |
2739 | (void)newsize; /* placate people compiling -Wunused-variable */ |
2740 | /* Prefer mremap, fall back to munmap */ |
2740 | /* Prefer mremap, fall back to munmap */ |
2741 | if ((CALL_MREMAP(sp->base, sp->size, newsize, 0) != MFAIL) || |
2741 | if ((CALL_MREMAP(sp->base, sp->size, newsize, 0) != MFAIL) || |
2742 | (CALL_MUNMAP(sp->base + newsize, extra) == 0)) { |
2742 | (CALL_MUNMAP(sp->base + newsize, extra) == 0)) { |
2743 | released = extra; |
2743 | released = extra; |
2744 | } |
2744 | } |
2745 | } |
2745 | } |
2746 | } |
2746 | } |
2747 | else if (HAVE_MORECORE) { |
2747 | else if (HAVE_MORECORE) { |
2748 | if (extra >= HALF_MAX_SIZE_T) /* Avoid wrapping negative */ |
2748 | if (extra >= HALF_MAX_SIZE_T) /* Avoid wrapping negative */ |
2749 | extra = (HALF_MAX_SIZE_T) + SIZE_T_ONE - unit; |
2749 | extra = (HALF_MAX_SIZE_T) + SIZE_T_ONE - unit; |
2750 | ACQUIRE_MALLOC_GLOBAL_LOCK(); |
2750 | ACQUIRE_MALLOC_GLOBAL_LOCK(); |
2751 | { |
2751 | { |
2752 | /* Make sure end of memory is where we last set it. */ |
2752 | /* Make sure end of memory is where we last set it. */ |
2753 | char* old_br = (char*)(CALL_MORECORE(0)); |
2753 | char* old_br = (char*)(CALL_MORECORE(0)); |
2754 | if (old_br == sp->base + sp->size) { |
2754 | if (old_br == sp->base + sp->size) { |
2755 | char* rel_br = (char*)(CALL_MORECORE(-extra)); |
2755 | char* rel_br = (char*)(CALL_MORECORE(-extra)); |
2756 | char* new_br = (char*)(CALL_MORECORE(0)); |
2756 | char* new_br = (char*)(CALL_MORECORE(0)); |
2757 | if (rel_br != CMFAIL && new_br < old_br) |
2757 | if (rel_br != CMFAIL && new_br < old_br) |
2758 | released = old_br - new_br; |
2758 | released = old_br - new_br; |
2759 | } |
2759 | } |
2760 | } |
2760 | } |
2761 | RELEASE_MALLOC_GLOBAL_LOCK(); |
2761 | RELEASE_MALLOC_GLOBAL_LOCK(); |
2762 | } |
2762 | } |
2763 | } |
2763 | } |
2764 | 2764 | ||
2765 | if (released != 0) { |
2765 | if (released != 0) { |
2766 | sp->size -= released; |
2766 | sp->size -= released; |
2767 | m->footprint -= released; |
2767 | m->footprint -= released; |
2768 | init_top(m, m->top, m->topsize - released); |
2768 | init_top(m, m->top, m->topsize - released); |
2769 | check_top_chunk(m, m->top); |
2769 | check_top_chunk(m, m->top); |
2770 | } |
2770 | } |
2771 | } |
2771 | } |
2772 | 2772 | ||
2773 | /* Unmap any unused mmapped segments */ |
2773 | /* Unmap any unused mmapped segments */ |
2774 | if (HAVE_MMAP) |
2774 | if (HAVE_MMAP) |
2775 | released += release_unused_segments(m); |
2775 | released += release_unused_segments(m); |
2776 | 2776 | ||
2777 | /* On failure, disable autotrim to avoid repeated failed future calls */ |
2777 | /* On failure, disable autotrim to avoid repeated failed future calls */ |
2778 | if (released == 0 && m->topsize > m->trim_check) |
2778 | if (released == 0 && m->topsize > m->trim_check) |
2779 | m->trim_check = MAX_SIZE_T; |
2779 | m->trim_check = MAX_SIZE_T; |
2780 | } |
2780 | } |
2781 | 2781 | ||
2782 | return (released != 0)? 1 : 0; |
2782 | return (released != 0)? 1 : 0; |
2783 | } |
2783 | } |
2784 | 2784 | ||
2785 | /* Consolidate and bin a chunk. Differs from exported versions |
2785 | /* Consolidate and bin a chunk. Differs from exported versions |
2786 | of free mainly in that the chunk need not be marked as inuse. |
2786 | of free mainly in that the chunk need not be marked as inuse. |
2787 | */ |
2787 | */ |
2788 | static void dispose_chunk(mstate m, mchunkptr p, size_t psize) { |
2788 | static void dispose_chunk(mstate m, mchunkptr p, size_t psize) { |
2789 | mchunkptr next = chunk_plus_offset(p, psize); |
2789 | mchunkptr next = chunk_plus_offset(p, psize); |
2790 | if (!pinuse(p)) { |
2790 | if (!pinuse(p)) { |
2791 | mchunkptr prev; |
2791 | mchunkptr prev; |
2792 | size_t prevsize = p->prev_foot; |
2792 | size_t prevsize = p->prev_foot; |
2793 | if (is_mmapped(p)) { |
2793 | if (is_mmapped(p)) { |
2794 | psize += prevsize + MMAP_FOOT_PAD; |
2794 | psize += prevsize + MMAP_FOOT_PAD; |
2795 | if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) |
2795 | if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) |
2796 | m->footprint -= psize; |
2796 | m->footprint -= psize; |
2797 | return; |
2797 | return; |
2798 | } |
2798 | } |
2799 | prev = chunk_minus_offset(p, prevsize); |
2799 | prev = chunk_minus_offset(p, prevsize); |
2800 | psize += prevsize; |
2800 | psize += prevsize; |
2801 | p = prev; |
2801 | p = prev; |
2802 | if (RTCHECK(ok_address(m, prev))) { /* consolidate backward */ |
2802 | if (RTCHECK(ok_address(m, prev))) { /* consolidate backward */ |
2803 | if (p != m->dv) { |
2803 | if (p != m->dv) { |
2804 | unlink_chunk(m, p, prevsize); |
2804 | unlink_chunk(m, p, prevsize); |
2805 | } |
2805 | } |
2806 | else if ((next->head & INUSE_BITS) == INUSE_BITS) { |
2806 | else if ((next->head & INUSE_BITS) == INUSE_BITS) { |
2807 | m->dvsize = psize; |
2807 | m->dvsize = psize; |
2808 | set_free_with_pinuse(p, psize, next); |
2808 | set_free_with_pinuse(p, psize, next); |
2809 | return; |
2809 | return; |
2810 | } |
2810 | } |
2811 | } |
2811 | } |
2812 | else { |
2812 | else { |
2813 | CORRUPTION_ERROR_ACTION(m); |
2813 | CORRUPTION_ERROR_ACTION(m); |
2814 | return; |
2814 | return; |
2815 | } |
2815 | } |
2816 | } |
2816 | } |
2817 | if (RTCHECK(ok_address(m, next))) { |
2817 | if (RTCHECK(ok_address(m, next))) { |
2818 | if (!cinuse(next)) { /* consolidate forward */ |
2818 | if (!cinuse(next)) { /* consolidate forward */ |
2819 | if (next == m->top) { |
2819 | if (next == m->top) { |
2820 | size_t tsize = m->topsize += psize; |
2820 | size_t tsize = m->topsize += psize; |
2821 | m->top = p; |
2821 | m->top = p; |
2822 | p->head = tsize | PINUSE_BIT; |
2822 | p->head = tsize | PINUSE_BIT; |
2823 | if (p == m->dv) { |
2823 | if (p == m->dv) { |
2824 | m->dv = 0; |
2824 | m->dv = 0; |
2825 | m->dvsize = 0; |
2825 | m->dvsize = 0; |
2826 | } |
2826 | } |
2827 | return; |
2827 | return; |
2828 | } |
2828 | } |
2829 | else if (next == m->dv) { |
2829 | else if (next == m->dv) { |
2830 | size_t dsize = m->dvsize += psize; |
2830 | size_t dsize = m->dvsize += psize; |
2831 | m->dv = p; |
2831 | m->dv = p; |
2832 | set_size_and_pinuse_of_free_chunk(p, dsize); |
2832 | set_size_and_pinuse_of_free_chunk(p, dsize); |
2833 | return; |
2833 | return; |
2834 | } |
2834 | } |
2835 | else { |
2835 | else { |
2836 | size_t nsize = chunksize(next); |
2836 | size_t nsize = chunksize(next); |
2837 | psize += nsize; |
2837 | psize += nsize; |
2838 | unlink_chunk(m, next, nsize); |
2838 | unlink_chunk(m, next, nsize); |
2839 | set_size_and_pinuse_of_free_chunk(p, psize); |
2839 | set_size_and_pinuse_of_free_chunk(p, psize); |
2840 | if (p == m->dv) { |
2840 | if (p == m->dv) { |
2841 | m->dvsize = psize; |
2841 | m->dvsize = psize; |
2842 | return; |
2842 | return; |
2843 | } |
2843 | } |
2844 | } |
2844 | } |
2845 | } |
2845 | } |
2846 | else { |
2846 | else { |
2847 | set_free_with_pinuse(p, psize, next); |
2847 | set_free_with_pinuse(p, psize, next); |
2848 | } |
2848 | } |
2849 | insert_chunk(m, p, psize); |
2849 | insert_chunk(m, p, psize); |
2850 | } |
2850 | } |
2851 | else { |
2851 | else { |
2852 | CORRUPTION_ERROR_ACTION(m); |
2852 | CORRUPTION_ERROR_ACTION(m); |
2853 | } |
2853 | } |
2854 | } |
2854 | } |
2855 | 2855 | ||
2856 | /* ---------------------------- malloc --------------------------- */ |
2856 | /* ---------------------------- malloc --------------------------- */ |
2857 | 2857 | ||
2858 | /* allocate a large request from the best fitting chunk in a treebin */ |
2858 | /* allocate a large request from the best fitting chunk in a treebin */ |
2859 | static void* tmalloc_large(mstate m, size_t nb) { |
2859 | static void* tmalloc_large(mstate m, size_t nb) { |
2860 | tchunkptr v = 0; |
2860 | tchunkptr v = 0; |
2861 | size_t rsize = -nb; /* Unsigned negation */ |
2861 | size_t rsize = -nb; /* Unsigned negation */ |
2862 | tchunkptr t; |
2862 | tchunkptr t; |
2863 | bindex_t idx; |
2863 | bindex_t idx; |
2864 | compute_tree_index(nb, idx); |
2864 | compute_tree_index(nb, idx); |
2865 | if ((t = *treebin_at(m, idx)) != 0) { |
2865 | if ((t = *treebin_at(m, idx)) != 0) { |
2866 | /* Traverse tree for this bin looking for node with size == nb */ |
2866 | /* Traverse tree for this bin looking for node with size == nb */ |
2867 | size_t sizebits = nb << leftshift_for_tree_index(idx); |
2867 | size_t sizebits = nb << leftshift_for_tree_index(idx); |
2868 | tchunkptr rst = 0; /* The deepest untaken right subtree */ |
2868 | tchunkptr rst = 0; /* The deepest untaken right subtree */ |
2869 | for (;;) { |
2869 | for (;;) { |
2870 | tchunkptr rt; |
2870 | tchunkptr rt; |
2871 | size_t trem = chunksize(t) - nb; |
2871 | size_t trem = chunksize(t) - nb; |
2872 | if (trem < rsize) { |
2872 | if (trem < rsize) { |
2873 | v = t; |
2873 | v = t; |
2874 | if ((rsize = trem) == 0) |
2874 | if ((rsize = trem) == 0) |
2875 | break; |
2875 | break; |
2876 | } |
2876 | } |
2877 | rt = t->child[1]; |
2877 | rt = t->child[1]; |
2878 | t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; |
2878 | t = t->child[(sizebits >> (SIZE_T_BITSIZE-SIZE_T_ONE)) & 1]; |
2879 | if (rt != 0 && rt != t) |
2879 | if (rt != 0 && rt != t) |
2880 | rst = rt; |
2880 | rst = rt; |
2881 | if (t == 0) { |
2881 | if (t == 0) { |
2882 | t = rst; /* set t to least subtree holding sizes > nb */ |
2882 | t = rst; /* set t to least subtree holding sizes > nb */ |
2883 | break; |
2883 | break; |
2884 | } |
2884 | } |
2885 | sizebits <<= 1; |
2885 | sizebits <<= 1; |
2886 | } |
2886 | } |
2887 | } |
2887 | } |
2888 | if (t == 0 && v == 0) { /* set t to root of next non-empty treebin */ |
2888 | if (t == 0 && v == 0) { /* set t to root of next non-empty treebin */ |
2889 | binmap_t leftbits = left_bits(idx2bit(idx)) & m->treemap; |
2889 | binmap_t leftbits = left_bits(idx2bit(idx)) & m->treemap; |
2890 | if (leftbits != 0) { |
2890 | if (leftbits != 0) { |
2891 | bindex_t i; |
2891 | bindex_t i; |
2892 | binmap_t leastbit = least_bit(leftbits); |
2892 | binmap_t leastbit = least_bit(leftbits); |
2893 | compute_bit2idx(leastbit, i); |
2893 | compute_bit2idx(leastbit, i); |
2894 | t = *treebin_at(m, i); |
2894 | t = *treebin_at(m, i); |
2895 | } |
2895 | } |
2896 | } |
2896 | } |
2897 | 2897 | ||
2898 | while (t != 0) { /* find smallest of tree or subtree */ |
2898 | while (t != 0) { /* find smallest of tree or subtree */ |
2899 | size_t trem = chunksize(t) - nb; |
2899 | size_t trem = chunksize(t) - nb; |
2900 | if (trem < rsize) { |
2900 | if (trem < rsize) { |
2901 | rsize = trem; |
2901 | rsize = trem; |
2902 | v = t; |
2902 | v = t; |
2903 | } |
2903 | } |
2904 | t = leftmost_child(t); |
2904 | t = leftmost_child(t); |
2905 | } |
2905 | } |
2906 | 2906 | ||
2907 | /* If dv is a better fit, return 0 so malloc will use it */ |
2907 | /* If dv is a better fit, return 0 so malloc will use it */ |
2908 | if (v != 0 && rsize < (size_t)(m->dvsize - nb)) { |
2908 | if (v != 0 && rsize < (size_t)(m->dvsize - nb)) { |
2909 | if (RTCHECK(ok_address(m, v))) { /* split */ |
2909 | if (RTCHECK(ok_address(m, v))) { /* split */ |
2910 | mchunkptr r = chunk_plus_offset(v, nb); |
2910 | mchunkptr r = chunk_plus_offset(v, nb); |
2911 | assert(chunksize(v) == rsize + nb); |
2911 | assert(chunksize(v) == rsize + nb); |
2912 | if (RTCHECK(ok_next(v, r))) { |
2912 | if (RTCHECK(ok_next(v, r))) { |
2913 | unlink_large_chunk(m, v); |
2913 | unlink_large_chunk(m, v); |
2914 | if (rsize < MIN_CHUNK_SIZE) |
2914 | if (rsize < MIN_CHUNK_SIZE) |
2915 | set_inuse_and_pinuse(m, v, (rsize + nb)); |
2915 | set_inuse_and_pinuse(m, v, (rsize + nb)); |
2916 | else { |
2916 | else { |
2917 | set_size_and_pinuse_of_inuse_chunk(m, v, nb); |
2917 | set_size_and_pinuse_of_inuse_chunk(m, v, nb); |
2918 | set_size_and_pinuse_of_free_chunk(r, rsize); |
2918 | set_size_and_pinuse_of_free_chunk(r, rsize); |
2919 | insert_chunk(m, r, rsize); |
2919 | insert_chunk(m, r, rsize); |
2920 | } |
2920 | } |
2921 | return chunk2mem(v); |
2921 | return chunk2mem(v); |
2922 | } |
2922 | } |
2923 | } |
2923 | } |
2924 | CORRUPTION_ERROR_ACTION(m); |
2924 | CORRUPTION_ERROR_ACTION(m); |
2925 | } |
2925 | } |
2926 | return 0; |
2926 | return 0; |
2927 | } |
2927 | } |
2928 | 2928 | ||
2929 | /* allocate a small request from the best fitting chunk in a treebin */ |
2929 | /* allocate a small request from the best fitting chunk in a treebin */ |
2930 | static void* tmalloc_small(mstate m, size_t nb) { |
2930 | static void* tmalloc_small(mstate m, size_t nb) { |
2931 | tchunkptr t, v; |
2931 | tchunkptr t, v; |
2932 | size_t rsize; |
2932 | size_t rsize; |
2933 | bindex_t i; |
2933 | bindex_t i; |
2934 | binmap_t leastbit = least_bit(m->treemap); |
2934 | binmap_t leastbit = least_bit(m->treemap); |
2935 | compute_bit2idx(leastbit, i); |
2935 | compute_bit2idx(leastbit, i); |
2936 | v = t = *treebin_at(m, i); |
2936 | v = t = *treebin_at(m, i); |
2937 | rsize = chunksize(t) - nb; |
2937 | rsize = chunksize(t) - nb; |
2938 | 2938 | ||
2939 | while ((t = leftmost_child(t)) != 0) { |
2939 | while ((t = leftmost_child(t)) != 0) { |
2940 | size_t trem = chunksize(t) - nb; |
2940 | size_t trem = chunksize(t) - nb; |
2941 | if (trem < rsize) { |
2941 | if (trem < rsize) { |
2942 | rsize = trem; |
2942 | rsize = trem; |
2943 | v = t; |
2943 | v = t; |
2944 | } |
2944 | } |
2945 | } |
2945 | } |
2946 | 2946 | ||
2947 | if (RTCHECK(ok_address(m, v))) { |
2947 | if (RTCHECK(ok_address(m, v))) { |
2948 | mchunkptr r = chunk_plus_offset(v, nb); |
2948 | mchunkptr r = chunk_plus_offset(v, nb); |
2949 | assert(chunksize(v) == rsize + nb); |
2949 | assert(chunksize(v) == rsize + nb); |
2950 | if (RTCHECK(ok_next(v, r))) { |
2950 | if (RTCHECK(ok_next(v, r))) { |
2951 | unlink_large_chunk(m, v); |
2951 | unlink_large_chunk(m, v); |
2952 | if (rsize < MIN_CHUNK_SIZE) |
2952 | if (rsize < MIN_CHUNK_SIZE) |
2953 | set_inuse_and_pinuse(m, v, (rsize + nb)); |
2953 | set_inuse_and_pinuse(m, v, (rsize + nb)); |
2954 | else { |
2954 | else { |
2955 | set_size_and_pinuse_of_inuse_chunk(m, v, nb); |
2955 | set_size_and_pinuse_of_inuse_chunk(m, v, nb); |
2956 | set_size_and_pinuse_of_free_chunk(r, rsize); |
2956 | set_size_and_pinuse_of_free_chunk(r, rsize); |
2957 | replace_dv(m, r, rsize); |
2957 | replace_dv(m, r, rsize); |
2958 | } |
2958 | } |
2959 | return chunk2mem(v); |
2959 | return chunk2mem(v); |
2960 | } |
2960 | } |
2961 | } |
2961 | } |
2962 | 2962 | ||
2963 | CORRUPTION_ERROR_ACTION(m); |
2963 | CORRUPTION_ERROR_ACTION(m); |
2964 | return 0; |
2964 | return 0; |
2965 | } |
2965 | } |
2966 | 2966 | ||
2967 | 2967 | ||
2968 | void* malloc(size_t bytes) |
2968 | void* malloc(size_t bytes) |
2969 | { |
2969 | { |
2970 | /* |
2970 | /* |
2971 | Basic algorithm: |
2971 | Basic algorithm: |
2972 | If a small request (< 256 bytes minus per-chunk overhead): |
2972 | If a small request (< 256 bytes minus per-chunk overhead): |
2973 | 1. If one exists, use a remainderless chunk in associated smallbin. |
2973 | 1. If one exists, use a remainderless chunk in associated smallbin. |
2974 | (Remainderless means that there are too few excess bytes to |
2974 | (Remainderless means that there are too few excess bytes to |
2975 | represent as a chunk.) |
2975 | represent as a chunk.) |
2976 | 2. If it is big enough, use the dv chunk, which is normally the |
2976 | 2. If it is big enough, use the dv chunk, which is normally the |
2977 | chunk adjacent to the one used for the most recent small request. |
2977 | chunk adjacent to the one used for the most recent small request. |
2978 | 3. If one exists, split the smallest available chunk in a bin, |
2978 | 3. If one exists, split the smallest available chunk in a bin, |
2979 | saving remainder in dv. |
2979 | saving remainder in dv. |
2980 | 4. If it is big enough, use the top chunk. |
2980 | 4. If it is big enough, use the top chunk. |
2981 | 5. If available, get memory from system and use it |
2981 | 5. If available, get memory from system and use it |
2982 | Otherwise, for a large request: |
2982 | Otherwise, for a large request: |
2983 | 1. Find the smallest available binned chunk that fits, and use it |
2983 | 1. Find the smallest available binned chunk that fits, and use it |
2984 | if it is better fitting than dv chunk, splitting if necessary. |
2984 | if it is better fitting than dv chunk, splitting if necessary. |
2985 | 2. If better fitting than any binned chunk, use the dv chunk. |
2985 | 2. If better fitting than any binned chunk, use the dv chunk. |
2986 | 3. If it is big enough, use the top chunk. |
2986 | 3. If it is big enough, use the top chunk. |
2987 | 4. If request size >= mmap threshold, try to directly mmap this chunk. |
2987 | 4. If request size >= mmap threshold, try to directly mmap this chunk. |
2988 | 5. If available, get memory from system and use it |
2988 | 5. If available, get memory from system and use it |
2989 | 2989 | ||
2990 | The ugly goto's here ensure that postaction occurs along all paths. |
2990 | The ugly goto's here ensure that postaction occurs along all paths. |
2991 | */ |
2991 | */ |
2992 | 2992 | ||
2993 | ensure_initialization(); /* initialize in sys_alloc if not using locks */ |
2993 | ensure_initialization(); /* initialize in sys_alloc if not using locks */ |
2994 | 2994 | ||
2995 | PREACTION(gm); |
2995 | PREACTION(gm); |
2996 | { |
2996 | { |
2997 | void* mem; |
2997 | void* mem; |
2998 | size_t nb; |
2998 | size_t nb; |
2999 | if (bytes <= MAX_SMALL_REQUEST) { |
2999 | if (bytes <= MAX_SMALL_REQUEST) { |
3000 | bindex_t idx; |
3000 | bindex_t idx; |
3001 | binmap_t smallbits; |
3001 | binmap_t smallbits; |
3002 | nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes); |
3002 | nb = (bytes < MIN_REQUEST)? MIN_CHUNK_SIZE : pad_request(bytes); |
3003 | idx = small_index(nb); |
3003 | idx = small_index(nb); |
3004 | smallbits = gm->smallmap >> idx; |
3004 | smallbits = gm->smallmap >> idx; |
3005 | 3005 | ||
3006 | if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */ |
3006 | if ((smallbits & 0x3U) != 0) { /* Remainderless fit to a smallbin. */ |
3007 | mchunkptr b, p; |
3007 | mchunkptr b, p; |
3008 | idx += ~smallbits & 1; /* Uses next bin if idx empty */ |
3008 | idx += ~smallbits & 1; /* Uses next bin if idx empty */ |
3009 | b = smallbin_at(gm, idx); |
3009 | b = smallbin_at(gm, idx); |
3010 | p = b->fd; |
3010 | p = b->fd; |
3011 | assert(chunksize(p) == small_index2size(idx)); |
3011 | assert(chunksize(p) == small_index2size(idx)); |
3012 | unlink_first_small_chunk(gm, b, p, idx); |
3012 | unlink_first_small_chunk(gm, b, p, idx); |
3013 | set_inuse_and_pinuse(gm, p, small_index2size(idx)); |
3013 | set_inuse_and_pinuse(gm, p, small_index2size(idx)); |
3014 | mem = chunk2mem(p); |
3014 | mem = chunk2mem(p); |
3015 | check_malloced_chunk(gm, mem, nb); |
3015 | check_malloced_chunk(gm, mem, nb); |
3016 | goto postaction; |
3016 | goto postaction; |
3017 | } |
3017 | } |
3018 | 3018 | ||
3019 | else if (nb > gm->dvsize) { |
3019 | else if (nb > gm->dvsize) { |
3020 | if (smallbits != 0) { /* Use chunk in next nonempty smallbin */ |
3020 | if (smallbits != 0) { /* Use chunk in next nonempty smallbin */ |
3021 | mchunkptr b, p, r; |
3021 | mchunkptr b, p, r; |
3022 | size_t rsize; |
3022 | size_t rsize; |
3023 | bindex_t i; |
3023 | bindex_t i; |
3024 | binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx)); |
3024 | binmap_t leftbits = (smallbits << idx) & left_bits(idx2bit(idx)); |
3025 | binmap_t leastbit = least_bit(leftbits); |
3025 | binmap_t leastbit = least_bit(leftbits); |
3026 | compute_bit2idx(leastbit, i); |
3026 | compute_bit2idx(leastbit, i); |
3027 | b = smallbin_at(gm, i); |
3027 | b = smallbin_at(gm, i); |
3028 | p = b->fd; |
3028 | p = b->fd; |
3029 | assert(chunksize(p) == small_index2size(i)); |
3029 | assert(chunksize(p) == small_index2size(i)); |
3030 | unlink_first_small_chunk(gm, b, p, i); |
3030 | unlink_first_small_chunk(gm, b, p, i); |
3031 | rsize = small_index2size(i) - nb; |
3031 | rsize = small_index2size(i) - nb; |
3032 | /* Fit here cannot be remainderless if 4byte sizes */ |
3032 | /* Fit here cannot be remainderless if 4byte sizes */ |
3033 | if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE) |
3033 | if (SIZE_T_SIZE != 4 && rsize < MIN_CHUNK_SIZE) |
3034 | set_inuse_and_pinuse(gm, p, small_index2size(i)); |
3034 | set_inuse_and_pinuse(gm, p, small_index2size(i)); |
3035 | else { |
3035 | else { |
3036 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); |
3036 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); |
3037 | r = chunk_plus_offset(p, nb); |
3037 | r = chunk_plus_offset(p, nb); |
3038 | set_size_and_pinuse_of_free_chunk(r, rsize); |
3038 | set_size_and_pinuse_of_free_chunk(r, rsize); |
3039 | replace_dv(gm, r, rsize); |
3039 | replace_dv(gm, r, rsize); |
3040 | } |
3040 | } |
3041 | mem = chunk2mem(p); |
3041 | mem = chunk2mem(p); |
3042 | check_malloced_chunk(gm, mem, nb); |
3042 | check_malloced_chunk(gm, mem, nb); |
3043 | goto postaction; |
3043 | goto postaction; |
3044 | } |
3044 | } |
3045 | 3045 | ||
3046 | else if (gm->treemap != 0 && (mem = tmalloc_small(gm, nb)) != 0) { |
3046 | else if (gm->treemap != 0 && (mem = tmalloc_small(gm, nb)) != 0) { |
3047 | check_malloced_chunk(gm, mem, nb); |
3047 | check_malloced_chunk(gm, mem, nb); |
3048 | goto postaction; |
3048 | goto postaction; |
3049 | } |
3049 | } |
3050 | } |
3050 | } |
3051 | } |
3051 | } |
3052 | else if (bytes >= MAX_REQUEST) |
3052 | else if (bytes >= MAX_REQUEST) |
3053 | nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */ |
3053 | nb = MAX_SIZE_T; /* Too big to allocate. Force failure (in sys alloc) */ |
3054 | else { |
3054 | else { |
3055 | nb = pad_request(bytes); |
3055 | nb = pad_request(bytes); |
3056 | if (gm->treemap != 0 && (mem = tmalloc_large(gm, nb)) != 0) { |
3056 | if (gm->treemap != 0 && (mem = tmalloc_large(gm, nb)) != 0) { |
3057 | check_malloced_chunk(gm, mem, nb); |
3057 | check_malloced_chunk(gm, mem, nb); |
3058 | goto postaction; |
3058 | goto postaction; |
3059 | } |
3059 | } |
3060 | } |
3060 | } |
3061 | 3061 | ||
3062 | if (nb <= gm->dvsize) { |
3062 | if (nb <= gm->dvsize) { |
3063 | size_t rsize = gm->dvsize - nb; |
3063 | size_t rsize = gm->dvsize - nb; |
3064 | mchunkptr p = gm->dv; |
3064 | mchunkptr p = gm->dv; |
3065 | if (rsize >= MIN_CHUNK_SIZE) { /* split dv */ |
3065 | if (rsize >= MIN_CHUNK_SIZE) { /* split dv */ |
3066 | mchunkptr r = gm->dv = chunk_plus_offset(p, nb); |
3066 | mchunkptr r = gm->dv = chunk_plus_offset(p, nb); |
3067 | gm->dvsize = rsize; |
3067 | gm->dvsize = rsize; |
3068 | set_size_and_pinuse_of_free_chunk(r, rsize); |
3068 | set_size_and_pinuse_of_free_chunk(r, rsize); |
3069 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); |
3069 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); |
3070 | } |
3070 | } |
3071 | else { /* exhaust dv */ |
3071 | else { /* exhaust dv */ |
3072 | size_t dvs = gm->dvsize; |
3072 | size_t dvs = gm->dvsize; |
3073 | gm->dvsize = 0; |
3073 | gm->dvsize = 0; |
3074 | gm->dv = 0; |
3074 | gm->dv = 0; |
3075 | set_inuse_and_pinuse(gm, p, dvs); |
3075 | set_inuse_and_pinuse(gm, p, dvs); |
3076 | } |
3076 | } |
3077 | mem = chunk2mem(p); |
3077 | mem = chunk2mem(p); |
3078 | check_malloced_chunk(gm, mem, nb); |
3078 | check_malloced_chunk(gm, mem, nb); |
3079 | goto postaction; |
3079 | goto postaction; |
3080 | } |
3080 | } |
3081 | 3081 | ||
3082 | else if (nb < gm->topsize) { /* Split top */ |
3082 | else if (nb < gm->topsize) { /* Split top */ |
3083 | size_t rsize = gm->topsize -= nb; |
3083 | size_t rsize = gm->topsize -= nb; |
3084 | mchunkptr p = gm->top; |
3084 | mchunkptr p = gm->top; |
3085 | mchunkptr r = gm->top = chunk_plus_offset(p, nb); |
3085 | mchunkptr r = gm->top = chunk_plus_offset(p, nb); |
3086 | r->head = rsize | PINUSE_BIT; |
3086 | r->head = rsize | PINUSE_BIT; |
3087 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); |
3087 | set_size_and_pinuse_of_inuse_chunk(gm, p, nb); |
3088 | mem = chunk2mem(p); |
3088 | mem = chunk2mem(p); |
3089 | check_top_chunk(gm, gm->top); |
3089 | check_top_chunk(gm, gm->top); |
3090 | check_malloced_chunk(gm, mem, nb); |
3090 | check_malloced_chunk(gm, mem, nb); |
3091 | goto postaction; |
3091 | goto postaction; |
3092 | } |
3092 | } |
3093 | 3093 | ||
3094 | mem = sys_alloc(gm, nb); |
3094 | mem = sys_alloc(gm, nb); |
3095 | 3095 | ||
3096 | postaction: |
3096 | postaction: |
3097 | POSTACTION(gm); |
3097 | POSTACTION(gm); |
3098 | // printf("%s %p %d\n", __FUNCTION__, mem, bytes); |
3098 | // printf("%s %p %d\n", __FUNCTION__, mem, bytes); |
3099 | return mem; |
3099 | return mem; |
3100 | } |
3100 | } |
3101 | // FAIL(); |
3101 | // FAIL(); |
3102 | return 0; |
3102 | return 0; |
3103 | } |
3103 | } |
3104 | 3104 | ||
3105 | /* ---------------------------- free --------------------------- */ |
3105 | /* ---------------------------- free --------------------------- */ |
3106 | 3106 | ||
3107 | void free(void* mem){ |
3107 | void free(void* mem){ |
3108 | /* |
3108 | /* |
3109 | Consolidate freed chunks with preceeding or succeeding bordering |
3109 | Consolidate freed chunks with preceeding or succeeding bordering |
3110 | free chunks, if they exist, and then place in a bin. Intermixed |
3110 | free chunks, if they exist, and then place in a bin. Intermixed |
3111 | with special cases for top, dv, mmapped chunks, and usage errors. |
3111 | with special cases for top, dv, mmapped chunks, and usage errors. |
3112 | */ |
3112 | */ |
3113 | 3113 | ||
3114 | // dbgprintf("%s %p\n", __FUNCTION__, mem); |
3114 | // dbgprintf("%s %p\n", __FUNCTION__, mem); |
3115 | 3115 | ||
3116 | if (mem != 0) { |
3116 | if (mem != 0) { |
3117 | mchunkptr p = mem2chunk(mem); |
3117 | mchunkptr p = mem2chunk(mem); |
3118 | #if FOOTERS |
3118 | #if FOOTERS |
3119 | mstate fm = get_mstate_for(p); |
3119 | mstate fm = get_mstate_for(p); |
3120 | if (!ok_magic(fm)) { |
3120 | if (!ok_magic(fm)) { |
3121 | USAGE_ERROR_ACTION(fm, p); |
3121 | USAGE_ERROR_ACTION(fm, p); |
3122 | return; |
3122 | return; |
3123 | } |
3123 | } |
3124 | #else /* FOOTERS */ |
3124 | #else /* FOOTERS */ |
3125 | #define fm gm |
3125 | #define fm gm |
3126 | #endif /* FOOTERS */ |
3126 | #endif /* FOOTERS */ |
3127 | PREACTION(fm); |
3127 | PREACTION(fm); |
3128 | { |
3128 | { |
3129 | check_inuse_chunk(fm, p); |
3129 | check_inuse_chunk(fm, p); |
3130 | if (RTCHECK(ok_address(fm, p) && ok_inuse(p))) { |
3130 | if (RTCHECK(ok_address(fm, p) && ok_inuse(p))) { |
3131 | size_t psize = chunksize(p); |
3131 | size_t psize = chunksize(p); |
3132 | mchunkptr next = chunk_plus_offset(p, psize); |
3132 | mchunkptr next = chunk_plus_offset(p, psize); |
3133 | if (!pinuse(p)) { |
3133 | if (!pinuse(p)) { |
3134 | size_t prevsize = p->prev_foot; |
3134 | size_t prevsize = p->prev_foot; |
3135 | if (is_mmapped(p)) { |
3135 | if (is_mmapped(p)) { |
3136 | psize += prevsize + MMAP_FOOT_PAD; |
3136 | psize += prevsize + MMAP_FOOT_PAD; |
3137 | if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) |
3137 | if (CALL_MUNMAP((char*)p - prevsize, psize) == 0) |
3138 | fm->footprint -= psize; |
3138 | fm->footprint -= psize; |
3139 | goto postaction; |
3139 | goto postaction; |
3140 | } |
3140 | } |
3141 | else { |
3141 | else { |
3142 | mchunkptr prev = chunk_minus_offset(p, prevsize); |
3142 | mchunkptr prev = chunk_minus_offset(p, prevsize); |
3143 | psize += prevsize; |
3143 | psize += prevsize; |
3144 | p = prev; |
3144 | p = prev; |
3145 | if (RTCHECK(ok_address(fm, prev))) { /* consolidate backward */ |
3145 | if (RTCHECK(ok_address(fm, prev))) { /* consolidate backward */ |
3146 | if (p != fm->dv) { |
3146 | if (p != fm->dv) { |
3147 | unlink_chunk(fm, p, prevsize); |
3147 | unlink_chunk(fm, p, prevsize); |
3148 | } |
3148 | } |
3149 | else if ((next->head & INUSE_BITS) == INUSE_BITS) { |
3149 | else if ((next->head & INUSE_BITS) == INUSE_BITS) { |
3150 | fm->dvsize = psize; |
3150 | fm->dvsize = psize; |
3151 | set_free_with_pinuse(p, psize, next); |
3151 | set_free_with_pinuse(p, psize, next); |
3152 | goto postaction; |
3152 | goto postaction; |
3153 | } |
3153 | } |
3154 | } |
3154 | } |
3155 | else |
3155 | else |
3156 | goto erroraction; |
3156 | goto erroraction; |
3157 | } |
3157 | } |
3158 | } |
3158 | } |
3159 | 3159 | ||
3160 | if (RTCHECK(ok_next(p, next) && ok_pinuse(next))) { |
3160 | if (RTCHECK(ok_next(p, next) && ok_pinuse(next))) { |
3161 | if (!cinuse(next)) { /* consolidate forward */ |
3161 | if (!cinuse(next)) { /* consolidate forward */ |
3162 | if (next == fm->top) { |
3162 | if (next == fm->top) { |
3163 | size_t tsize = fm->topsize += psize; |
3163 | size_t tsize = fm->topsize += psize; |
3164 | fm->top = p; |
3164 | fm->top = p; |
3165 | p->head = tsize | PINUSE_BIT; |
3165 | p->head = tsize | PINUSE_BIT; |
3166 | if (p == fm->dv) { |
3166 | if (p == fm->dv) { |
3167 | fm->dv = 0; |
3167 | fm->dv = 0; |
3168 | fm->dvsize = 0; |
3168 | fm->dvsize = 0; |
3169 | } |
3169 | } |
3170 | if (should_trim(fm, tsize)) |
3170 | if (should_trim(fm, tsize)) |
3171 | sys_trim(fm, 0); |
3171 | sys_trim(fm, 0); |
3172 | goto postaction; |
3172 | goto postaction; |
3173 | } |
3173 | } |
3174 | else if (next == fm->dv) { |
3174 | else if (next == fm->dv) { |
3175 | size_t dsize = fm->dvsize += psize; |
3175 | size_t dsize = fm->dvsize += psize; |
3176 | fm->dv = p; |
3176 | fm->dv = p; |
3177 | set_size_and_pinuse_of_free_chunk(p, dsize); |
3177 | set_size_and_pinuse_of_free_chunk(p, dsize); |
3178 | goto postaction; |
3178 | goto postaction; |
3179 | } |
3179 | } |
3180 | else { |
3180 | else { |
3181 | size_t nsize = chunksize(next); |
3181 | size_t nsize = chunksize(next); |
3182 | psize += nsize; |
3182 | psize += nsize; |
3183 | unlink_chunk(fm, next, nsize); |
3183 | unlink_chunk(fm, next, nsize); |
3184 | set_size_and_pinuse_of_free_chunk(p, psize); |
3184 | set_size_and_pinuse_of_free_chunk(p, psize); |
3185 | if (p == fm->dv) { |
3185 | if (p == fm->dv) { |
3186 | fm->dvsize = psize; |
3186 | fm->dvsize = psize; |
3187 | goto postaction; |
3187 | goto postaction; |
3188 | } |
3188 | } |
3189 | } |
3189 | } |
3190 | } |
3190 | } |
3191 | else |
3191 | else |
3192 | set_free_with_pinuse(p, psize, next); |
3192 | set_free_with_pinuse(p, psize, next); |
3193 | 3193 | ||
3194 | if (is_small(psize)) { |
3194 | if (is_small(psize)) { |
3195 | insert_small_chunk(fm, p, psize); |
3195 | insert_small_chunk(fm, p, psize); |
3196 | check_free_chunk(fm, p); |
3196 | check_free_chunk(fm, p); |
3197 | } |
3197 | } |
3198 | else { |
3198 | else { |
3199 | tchunkptr tp = (tchunkptr)p; |
3199 | tchunkptr tp = (tchunkptr)p; |
3200 | insert_large_chunk(fm, tp, psize); |
3200 | insert_large_chunk(fm, tp, psize); |
3201 | check_free_chunk(fm, p); |
3201 | check_free_chunk(fm, p); |
3202 | if (--fm->release_checks == 0) |
3202 | if (--fm->release_checks == 0) |
3203 | release_unused_segments(fm); |
3203 | release_unused_segments(fm); |
3204 | } |
3204 | } |
3205 | goto postaction; |
3205 | goto postaction; |
3206 | } |
3206 | } |
3207 | } |
3207 | } |
3208 | erroraction: |
3208 | erroraction: |
3209 | USAGE_ERROR_ACTION(fm, p); |
3209 | USAGE_ERROR_ACTION(fm, p); |
3210 | postaction: |
3210 | postaction: |
3211 | POSTACTION(fm); |
3211 | POSTACTION(fm); |
3212 | } |
3212 | } |
3213 | } |
3213 | } |
3214 | 3214 | ||
3215 | // LEAVE(); |
3215 | // LEAVE(); |
3216 | 3216 | ||
3217 | #if !FOOTERS |
3217 | #if !FOOTERS |
3218 | #undef fm |
3218 | #undef fm |
3219 | #endif /* FOOTERS */ |
3219 | #endif /* FOOTERS */ |
3220 | } |
3220 | } |
3221 | 3221 | ||
3222 | void* calloc(size_t n_elements, size_t elem_size) { |
3222 | void* calloc(size_t n_elements, size_t elem_size) { |
3223 | void* mem; |
3223 | void* mem; |
3224 | size_t req = 0; |
3224 | size_t req = 0; |
3225 | if (n_elements != 0) { |
3225 | if (n_elements != 0) { |
3226 | req = n_elements * elem_size; |
3226 | req = n_elements * elem_size; |
3227 | if (((n_elements | elem_size) & ~(size_t)0xffff) && |
3227 | if (((n_elements | elem_size) & ~(size_t)0xffff) && |
3228 | (req / n_elements != elem_size)) |
3228 | (req / n_elements != elem_size)) |
3229 | req = MAX_SIZE_T; /* force downstream failure on overflow */ |
3229 | req = MAX_SIZE_T; /* force downstream failure on overflow */ |
3230 | } |
3230 | } |
3231 | mem = malloc(req); |
3231 | mem = malloc(req); |
3232 | if (mem != 0 && calloc_must_clear(mem2chunk(mem))) |
3232 | if (mem != 0 && calloc_must_clear(mem2chunk(mem))) |
3233 | memset(mem, 0, req); |
3233 | memset(mem, 0, req); |
3234 | return mem; |
3234 | return mem; |
3235 | } |
3235 | } |
3236 | 3236 | ||
3237 | /* ------------ Internal support for realloc, memalign, etc -------------- */ |
3237 | /* ------------ Internal support for realloc, memalign, etc -------------- */ |
3238 | 3238 | ||
3239 | /* Try to realloc; only in-place unless can_move true */ |
3239 | /* Try to realloc; only in-place unless can_move true */ |
3240 | static mchunkptr try_realloc_chunk(mstate m, mchunkptr p, size_t nb, |
3240 | static mchunkptr try_realloc_chunk(mstate m, mchunkptr p, size_t nb, |
3241 | int can_move) { |
3241 | int can_move) { |
3242 | mchunkptr newp = 0; |
3242 | mchunkptr newp = 0; |
3243 | size_t oldsize = chunksize(p); |
3243 | size_t oldsize = chunksize(p); |
3244 | mchunkptr next = chunk_plus_offset(p, oldsize); |
3244 | mchunkptr next = chunk_plus_offset(p, oldsize); |
3245 | if (RTCHECK(ok_address(m, p) && ok_inuse(p) && |
3245 | if (RTCHECK(ok_address(m, p) && ok_inuse(p) && |
3246 | ok_next(p, next) && ok_pinuse(next))) { |
3246 | ok_next(p, next) && ok_pinuse(next))) { |
3247 | if (is_mmapped(p)) { |
3247 | if (is_mmapped(p)) { |
3248 | newp = mmap_resize(m, p, nb, can_move); |
3248 | newp = mmap_resize(m, p, nb, can_move); |
3249 | } |
3249 | } |
3250 | else if (oldsize >= nb) { /* already big enough */ |
3250 | else if (oldsize >= nb) { /* already big enough */ |
3251 | size_t rsize = oldsize - nb; |
3251 | size_t rsize = oldsize - nb; |
3252 | if (rsize >= MIN_CHUNK_SIZE) { /* split off remainder */ |
3252 | if (rsize >= MIN_CHUNK_SIZE) { /* split off remainder */ |
3253 | mchunkptr r = chunk_plus_offset(p, nb); |
3253 | mchunkptr r = chunk_plus_offset(p, nb); |
3254 | set_inuse(m, p, nb); |
3254 | set_inuse(m, p, nb); |
3255 | set_inuse(m, r, rsize); |
3255 | set_inuse(m, r, rsize); |
3256 | dispose_chunk(m, r, rsize); |
3256 | dispose_chunk(m, r, rsize); |
3257 | } |
3257 | } |
3258 | newp = p; |
3258 | newp = p; |
3259 | } |
3259 | } |
3260 | else if (next == m->top) { /* extend into top */ |
3260 | else if (next == m->top) { /* extend into top */ |
3261 | if (oldsize + m->topsize > nb) { |
3261 | if (oldsize + m->topsize > nb) { |
3262 | size_t newsize = oldsize + m->topsize; |
3262 | size_t newsize = oldsize + m->topsize; |
3263 | size_t newtopsize = newsize - nb; |
3263 | size_t newtopsize = newsize - nb; |
3264 | mchunkptr newtop = chunk_plus_offset(p, nb); |
3264 | mchunkptr newtop = chunk_plus_offset(p, nb); |
3265 | set_inuse(m, p, nb); |
3265 | set_inuse(m, p, nb); |
3266 | newtop->head = newtopsize |PINUSE_BIT; |
3266 | newtop->head = newtopsize |PINUSE_BIT; |
3267 | m->top = newtop; |
3267 | m->top = newtop; |
3268 | m->topsize = newtopsize; |
3268 | m->topsize = newtopsize; |
3269 | newp = p; |
3269 | newp = p; |
3270 | } |
3270 | } |
3271 | } |
3271 | } |
3272 | else if (next == m->dv) { /* extend into dv */ |
3272 | else if (next == m->dv) { /* extend into dv */ |
3273 | size_t dvs = m->dvsize; |
3273 | size_t dvs = m->dvsize; |
3274 | if (oldsize + dvs >= nb) { |
3274 | if (oldsize + dvs >= nb) { |
3275 | size_t dsize = oldsize + dvs - nb; |
3275 | size_t dsize = oldsize + dvs - nb; |
3276 | if (dsize >= MIN_CHUNK_SIZE) { |
3276 | if (dsize >= MIN_CHUNK_SIZE) { |
3277 | mchunkptr r = chunk_plus_offset(p, nb); |
3277 | mchunkptr r = chunk_plus_offset(p, nb); |
3278 | mchunkptr n = chunk_plus_offset(r, dsize); |
3278 | mchunkptr n = chunk_plus_offset(r, dsize); |
3279 | set_inuse(m, p, nb); |
3279 | set_inuse(m, p, nb); |
3280 | set_size_and_pinuse_of_free_chunk(r, dsize); |
3280 | set_size_and_pinuse_of_free_chunk(r, dsize); |
3281 | clear_pinuse(n); |
3281 | clear_pinuse(n); |
3282 | m->dvsize = dsize; |
3282 | m->dvsize = dsize; |
3283 | m->dv = r; |
3283 | m->dv = r; |
3284 | } |
3284 | } |
3285 | else { /* exhaust dv */ |
3285 | else { /* exhaust dv */ |
3286 | size_t newsize = oldsize + dvs; |
3286 | size_t newsize = oldsize + dvs; |
3287 | set_inuse(m, p, newsize); |
3287 | set_inuse(m, p, newsize); |
3288 | m->dvsize = 0; |
3288 | m->dvsize = 0; |
3289 | m->dv = 0; |
3289 | m->dv = 0; |
3290 | } |
3290 | } |
3291 | newp = p; |
3291 | newp = p; |
3292 | } |
3292 | } |
3293 | } |
3293 | } |
3294 | else if (!cinuse(next)) { /* extend into next free chunk */ |
3294 | else if (!cinuse(next)) { /* extend into next free chunk */ |
3295 | size_t nextsize = chunksize(next); |
3295 | size_t nextsize = chunksize(next); |
3296 | if (oldsize + nextsize >= nb) { |
3296 | if (oldsize + nextsize >= nb) { |
3297 | size_t rsize = oldsize + nextsize - nb; |
3297 | size_t rsize = oldsize + nextsize - nb; |
3298 | unlink_chunk(m, next, nextsize); |
3298 | unlink_chunk(m, next, nextsize); |
3299 | if (rsize < MIN_CHUNK_SIZE) { |
3299 | if (rsize < MIN_CHUNK_SIZE) { |
3300 | size_t newsize = oldsize + nextsize; |
3300 | size_t newsize = oldsize + nextsize; |
3301 | set_inuse(m, p, newsize); |
3301 | set_inuse(m, p, newsize); |
3302 | } |
3302 | } |
3303 | else { |
3303 | else { |
3304 | mchunkptr r = chunk_plus_offset(p, nb); |
3304 | mchunkptr r = chunk_plus_offset(p, nb); |
3305 | set_inuse(m, p, nb); |
3305 | set_inuse(m, p, nb); |
3306 | set_inuse(m, r, rsize); |
3306 | set_inuse(m, r, rsize); |
3307 | dispose_chunk(m, r, rsize); |
3307 | dispose_chunk(m, r, rsize); |
3308 | } |
3308 | } |
3309 | newp = p; |
3309 | newp = p; |
3310 | } |
3310 | } |
3311 | } |
3311 | } |
3312 | } |
3312 | } |
3313 | else { |
3313 | else { |
3314 | USAGE_ERROR_ACTION(m, chunk2mem(p)); |
3314 | USAGE_ERROR_ACTION(m, chunk2mem(p)); |
3315 | } |
3315 | } |
3316 | return newp; |
3316 | return newp; |
3317 | } |
3317 | } |
3318 | 3318 | ||
3319 | 3319 | ||
3320 | void* realloc(void* oldmem, size_t bytes) { |
3320 | void* realloc(void* oldmem, size_t bytes) { |
3321 | void* mem = 0; |
3321 | void* mem = 0; |
3322 | if (oldmem == 0) { |
3322 | if (oldmem == 0) { |
3323 | mem = malloc(bytes); |
3323 | mem = malloc(bytes); |
3324 | } |
3324 | } |
3325 | else if (bytes >= MAX_REQUEST) { |
3325 | else if (bytes >= MAX_REQUEST) { |
3326 | // MALLOC_FAILURE_ACTION; |
3326 | // MALLOC_FAILURE_ACTION; |
3327 | } |
3327 | } |
3328 | #ifdef REALLOC_ZERO_BYTES_FREES |
3328 | #ifdef REALLOC_ZERO_BYTES_FREES |
3329 | else if (bytes == 0) { |
3329 | else if (bytes == 0) { |
3330 | free(oldmem); |
3330 | free(oldmem); |
3331 | } |
3331 | } |
3332 | #endif /* REALLOC_ZERO_BYTES_FREES */ |
3332 | #endif /* REALLOC_ZERO_BYTES_FREES */ |
3333 | else { |
3333 | else { |
3334 | size_t nb = request2size(bytes); |
3334 | size_t nb = request2size(bytes); |
3335 | mchunkptr oldp = mem2chunk(oldmem); |
3335 | mchunkptr oldp = mem2chunk(oldmem); |
3336 | #if ! FOOTERS |
3336 | #if ! FOOTERS |
3337 | mstate m = gm; |
3337 | mstate m = gm; |
3338 | #else /* FOOTERS */ |
3338 | #else /* FOOTERS */ |
3339 | mstate m = get_mstate_for(oldp); |
3339 | mstate m = get_mstate_for(oldp); |
3340 | if (!ok_magic(m)) { |
3340 | if (!ok_magic(m)) { |
3341 | USAGE_ERROR_ACTION(m, oldmem); |
3341 | USAGE_ERROR_ACTION(m, oldmem); |
3342 | return 0; |
3342 | return 0; |
3343 | } |
3343 | } |
3344 | #endif /* FOOTERS */ |
3344 | #endif /* FOOTERS */ |
3345 | PREACTION(m); { |
3345 | PREACTION(m); { |
3346 | mchunkptr newp = try_realloc_chunk(m, oldp, nb, 1); |
3346 | mchunkptr newp = try_realloc_chunk(m, oldp, nb, 1); |
3347 | POSTACTION(m); |
3347 | POSTACTION(m); |
3348 | if (newp != 0) { |
3348 | if (newp != 0) { |
3349 | check_inuse_chunk(m, newp); |
3349 | check_inuse_chunk(m, newp); |
3350 | mem = chunk2mem(newp); |
3350 | mem = chunk2mem(newp); |
3351 | } |
3351 | } |
3352 | else { |
3352 | else { |
3353 | mem = internal_malloc(m, bytes); |
3353 | mem = internal_malloc(m, bytes); |
3354 | if (mem != 0) { |
3354 | if (mem != 0) { |
3355 | size_t oc = chunksize(oldp) - overhead_for(oldp); |
3355 | size_t oc = chunksize(oldp) - overhead_for(oldp); |
3356 | memcpy(mem, oldmem, (oc < bytes)? oc : bytes); |
3356 | memcpy(mem, oldmem, (oc < bytes)? oc : bytes); |
3357 | internal_free(m, oldmem); |
3357 | internal_free(m, oldmem); |
3358 | } |
3358 | } |
3359 | } |
3359 | } |
3360 | } |
3360 | } |
3361 | } |
3361 | } |
3362 | return mem; |
3362 | return mem; |
3363 | }>>>=>>><>>=>>>>>>>=><=>>><>>>>>>>>>>>>=>>=>=>>>>>><>=>>=>=><=>><>=>=>>>=><=>><>><>><>>>>>1)) |
3363 | }>>>=>>><>>=>>>>>>>=><=>>><>>>>>>>>>>>>=>>=>=>>>>>><>=>>=>=><=>><>=>=>>>=><=>><>><>><>>>>>1)) |
3364 | 3364 | ||
3365 | /*><1)) |
3365 | /*><1)) |
3366 | 3366 | ||
3367 | /*>1)><1)>><>><>><>><>1]))) |
3367 | /*>1)><1)>><>><>><>><>1]))) |
3368 | #define><1]))) |
3368 | #define><1]))) |
3369 | #define>><>>>>>><>><>>=>>=>>=>>><>2) |
3369 | #define>><>>>>>><>><>>=>>=>>=>>><>2) |
3370 | #define><2) |
3370 | #define><2) |
3371 | #define>1) |
3371 | #define>1) |
3372 | #define><1) |
3372 | #define><1) |
3373 | #define>><> |
3373 | #define>><> |