/*
** $Id: lstate.h,v 2.68 2010/10/29 17:52:46 roberto Exp $
** Global State
** See Copyright Notice in lua.h
*/
#ifndef lstate_h
#define lstate_h
#include "lua.h"
#include "lobject.h"
#include "ltm.h"
#include "lzio.h"
/*
** Some notes about garbage-collected objects: All objects in Lua must
** be kept somehow accessible until being freed.
**
** Lua keeps most objects linked in list g->allgc. The link uses field
** 'next' of the CommonHeader.
**
** Strings are kept in several lists headed by the array g->strt.hash.
**
** Open upvalues are not subject to independent garbage collection. They
** are collected together with their respective threads. Lua keeps a
** double-linked list with all open upvalues (g->uvhead) so that it can
** mark objects referred by them. (They are always gray, so they must
** be remarked in the atomic step. Usually their contents would be marked
** when traversing the respective threads, but the thread may already be
** dead, while the upvalue is still accessible through closures.)
**
** Userdata with finalizers are kept in the list g->udgc.
**
** The list g->tobefnz links all userdata being finalized.
*/
struct lua_longjmp; /* defined in ldo.c */
/* extra stack space to handle TM calls and some other extras */
#define EXTRA_STACK 5
#define BASIC_CI_SIZE 8
#define BASIC_STACK_SIZE (2*LUA_MINSTACK)
/* kinds of Garbage Collection */
#define KGC_NORMAL 0
#define KGC_EMERGENCY 1 /* gc was forced by an allocation failure */
#define KGC_GEN 2 /* generational collection */
typedef struct stringtable {
GCObject **hash;
lu_int32 nuse; /* number of elements */
int size;
} stringtable;
/*
** information about a call
*/
typedef struct CallInfo {
StkId func; /* function index in the stack */
StkId top; /* top for this function */
struct CallInfo *previous, *next; /* dynamic call link */
short nresults; /* expected number of results from this function */
lu_byte callstatus;
union {
struct { /* only for Lua functions */
StkId base; /* base for this function */
const Instruction *savedpc;
} l;
struct { /* only for C functions */
int ctx; /* context info. in case of yields */
lua_CFunction k; /* continuation in case of yields */
ptrdiff_t old_errfunc;
ptrdiff_t extra;
lu_byte old_allowhook;
lu_byte status;
} c;
} u;
} CallInfo;
/*
** Bits in CallInfo status
*/
#define CIST_LUA (1<<0) /* call is running a Lua function */
#define CIST_HOOKED (1<<1) /* call is running a debug hook */
#define CIST_REENTRY (1<<2) /* call is running on same invocation of
luaV_execute of previous call */
#define CIST_YIELDED (1<<3) /* call reentered after suspension */
#define CIST_YPCALL (1<<4) /* call is a yieldable protected call */
#define CIST_STAT (1<<5) /* call has an error status (pcall) */
#define CIST_TAIL (1<<6) /* call was tail called */
#define ci_func(ci) (clvalue((ci)->func))
#define isLua(ci) ((ci)->callstatus & CIST_LUA)
/*
** `global state', shared by all threads of this state
*/
typedef struct global_State {
lua_Alloc frealloc; /* function to reallocate memory */
void *ud; /* auxiliary data to `frealloc' */
lu_mem totalbytes; /* number of bytes currently allocated */
l_mem GCdebt; /* when positive, run a GC step */
lu_mem lastmajormem; /* memory in use after last major collection */
stringtable strt; /* hash table for strings */
TValue l_registry;
unsigned short nCcalls; /* number of nested C calls */
lu_byte currentwhite;
lu_byte gcstate; /* state of garbage collector */
lu_byte gckind; /* kind of GC running */
int sweepstrgc; /* position of sweep in `strt' */
GCObject *allgc; /* list of all collectable objects */
GCObject *udgc; /* list of collectable userdata with finalizers */
GCObject **sweepgc; /* current position of sweep */
GCObject *gray; /* list of gray objects */
GCObject *grayagain; /* list of objects to be traversed atomically */
GCObject *weak; /* list of tables with weak values */
GCObject *ephemeron; /* list of ephemeron tables (weak keys) */
GCObject *allweak; /* list of all-weak tables */
GCObject *tobefnz; /* list of userdata to be GC */
UpVal uvhead; /* head of double-linked list of all open upvalues */
Mbuffer buff; /* temporary buffer for string concatenation */
int gcpause; /* size of pause between successive GCs */
int gcmajorinc; /* how much to wait for a major GC (only in gen. mode) */
int gcstepmul; /* GC `granularity' */
lua_CFunction panic; /* to be called in unprotected errors */
struct lua_State *mainthread;
const lua_Number *version; /* pointer to version number */
TString *memerrmsg; /* memory-error message */
TString *tmname[TM_N]; /* array with tag-method names */
struct Table *mt[LUA_NUMTAGS]; /* metatables for basic types */
} global_State;
/*
** `per thread' state
*/
struct lua_State {
CommonHeader;
lu_byte status;
StkId top; /* first free slot in the stack */
global_State *l_G;
CallInfo *ci; /* call info for current function */
const Instruction *oldpc; /* last pc traced */
StkId stack_last; /* last free slot in the stack */
StkId stack; /* stack base */
int stacksize;
unsigned short nny; /* number of non-yieldable calls in stack */
lu_byte hookmask;
lu_byte allowhook;
int basehookcount;
int hookcount;
lua_Hook hook;
GCObject *openupval; /* list of open upvalues in this stack */
GCObject *gclist;
struct lua_longjmp *errorJmp; /* current error recover point */
ptrdiff_t errfunc; /* current error handling function (stack index) */
CallInfo base_ci; /* CallInfo for first level (C calling Lua) */
};
#define G(L) (L->l_G)
/*
** Union of all collectable objects
*/
union GCObject {
GCheader gch; /* common header */
union TString ts;
union Udata u;
union Closure cl;
struct Table h;
struct Proto p;
struct UpVal uv;
struct lua_State th; /* thread */
};
#define gch(o) (&(o)->gch)
/* macros to convert a GCObject into a specific value */
#define rawgco2ts(o) check_exp((o)->gch.tt == LUA_TSTRING, &((o)->ts))
#define gco2ts(o) (&rawgco2ts(o)->tsv)
#define rawgco2u(o) check_exp((o)->gch.tt == LUA_TUSERDATA, &((o)->u))
#define gco2u(o) (&rawgco2u(o)->uv)
#define gco2cl(o) check_exp((o)->gch.tt == LUA_TFUNCTION, &((o)->cl))
#define gco2t(o) check_exp((o)->gch.tt == LUA_TTABLE, &((o)->h))
#define gco2p(o) check_exp((o)->gch.tt == LUA_TPROTO, &((o)->p))
#define gco2uv(o) check_exp((o)->gch.tt == LUA_TUPVAL, &((o)->uv))
#define gco2th(o) check_exp((o)->gch.tt == LUA_TTHREAD, &((o)->th))
/* macro to convert any Lua object into a GCObject */
#define obj2gco(v) (cast(GCObject *, (v)))
LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1);
LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L);
LUAI_FUNC void luaE_freeCI (lua_State *L);
#endif