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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 5131 | clevermous | 1 | /* |
| 2 | SDL - Simple DirectMedia Layer |
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| 3 | Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga |
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| 4 | |||
| 5 | This library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Library General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2 of the License, or (at your option) any later version. |
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| 9 | |||
| 10 | This library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Library General Public License for more details. |
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| 14 | |||
| 15 | You should have received a copy of the GNU Library General Public |
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| 16 | License along with this library; if not, write to the Free |
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| 17 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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| 18 | |||
| 19 | Sam Lantinga |
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| 20 | slouken@devolution.com |
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| 21 | */ |
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| 22 | |||
| 23 | #ifdef SAVE_RCSID |
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| 24 | static char rcsid = |
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| 25 | "@(#) $Id: SDL_mutex.h,v 1.2 2001/04/26 16:50:17 hercules Exp $"; |
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| 26 | #endif |
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| 27 | |||
| 28 | #ifndef _SDL_mutex_h |
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| 29 | #define _SDL_mutex_h |
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| 30 | |||
| 31 | /* Functions to provide thread synchronization primitives |
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| 32 | |||
| 33 | These are independent of the other SDL routines. |
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| 34 | */ |
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| 35 | |||
| 36 | #include "SDL_main.h" |
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| 37 | #include "SDL_types.h" |
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| 38 | |||
| 39 | #include "begin_code.h" |
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| 40 | /* Set up for C function definitions, even when using C++ */ |
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| 41 | #ifdef __cplusplus |
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| 42 | extern "C" { |
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| 43 | #endif |
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| 44 | |||
| 45 | /* Synchronization functions which can time out return this value |
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| 46 | if they time out. |
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| 47 | */ |
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| 48 | #define SDL_MUTEX_TIMEDOUT 1 |
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| 49 | |||
| 50 | /* This is the timeout value which corresponds to never time out */ |
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| 51 | #define SDL_MUTEX_MAXWAIT (~(Uint32)0) |
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| 52 | |||
| 53 | |||
| 54 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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| 55 | /* Mutex functions */ |
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| 56 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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| 57 | |||
| 58 | /* The SDL mutex structure, defined in SDL_mutex.c */ |
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| 59 | struct SDL_mutex; |
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| 60 | typedef struct SDL_mutex SDL_mutex; |
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| 61 | |||
| 62 | /* Create a mutex, initialized unlocked */ |
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| 63 | extern DECLSPEC SDL_mutex * SDL_CreateMutex(void); |
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| 64 | |||
| 65 | /* Lock the mutex (Returns 0, or -1 on error) */ |
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| 66 | #define SDL_LockMutex(m) SDL_mutexP(m) |
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| 67 | extern DECLSPEC int SDL_mutexP(SDL_mutex *mutex); |
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| 68 | |||
| 69 | /* Unlock the mutex (Returns 0, or -1 on error) */ |
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| 70 | #define SDL_UnlockMutex(m) SDL_mutexV(m) |
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| 71 | extern DECLSPEC int SDL_mutexV(SDL_mutex *mutex); |
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| 72 | |||
| 73 | /* Destroy a mutex */ |
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| 74 | extern DECLSPEC void SDL_DestroyMutex(SDL_mutex *mutex); |
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| 75 | |||
| 76 | |||
| 77 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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| 78 | /* Semaphore functions */ |
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| 79 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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| 80 | |||
| 81 | /* The SDL semaphore structure, defined in SDL_sem.c */ |
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| 82 | struct SDL_semaphore; |
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| 83 | typedef struct SDL_semaphore SDL_sem; |
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| 84 | |||
| 85 | /* Create a semaphore, initialized with value, returns NULL on failure. */ |
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| 86 | extern DECLSPEC SDL_sem * SDL_CreateSemaphore(Uint32 initial_value); |
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| 87 | |||
| 88 | /* Destroy a semaphore */ |
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| 89 | extern DECLSPEC void SDL_DestroySemaphore(SDL_sem *sem); |
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| 90 | |||
| 91 | /* This function suspends the calling thread until the semaphore pointed |
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| 92 | * to by sem has a positive count. It then atomically decreases the semaphore |
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| 93 | * count. |
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| 94 | */ |
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| 95 | extern DECLSPEC int SDL_SemWait(SDL_sem *sem); |
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| 96 | |||
| 97 | /* Non-blocking variant of SDL_SemWait(), returns 0 if the wait succeeds, |
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| 98 | SDL_MUTEX_TIMEDOUT if the wait would block, and -1 on error. |
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| 99 | */ |
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| 100 | extern DECLSPEC int SDL_SemTryWait(SDL_sem *sem); |
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| 101 | |||
| 102 | /* Variant of SDL_SemWait() with a timeout in milliseconds, returns 0 if |
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| 103 | the wait succeeds, SDL_MUTEX_TIMEDOUT if the wait does not succeed in |
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| 104 | the allotted time, and -1 on error. |
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| 105 | On some platforms this function is implemented by looping with a delay |
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| 106 | of 1 ms, and so should be avoided if possible. |
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| 107 | */ |
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| 108 | extern DECLSPEC int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 ms); |
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| 109 | |||
| 110 | /* Atomically increases the semaphore's count (not blocking), returns 0, |
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| 111 | or -1 on error. |
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| 112 | */ |
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| 113 | extern DECLSPEC int SDL_SemPost(SDL_sem *sem); |
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| 114 | |||
| 115 | /* Returns the current count of the semaphore */ |
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| 116 | extern DECLSPEC Uint32 SDL_SemValue(SDL_sem *sem); |
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| 117 | |||
| 118 | |||
| 119 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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| 120 | /* Condition variable functions */ |
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| 121 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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| 122 | |||
| 123 | /* The SDL condition variable structure, defined in SDL_cond.c */ |
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| 124 | struct SDL_cond; |
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| 125 | typedef struct SDL_cond SDL_cond; |
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| 126 | |||
| 127 | /* Create a condition variable */ |
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| 128 | extern DECLSPEC SDL_cond * SDL_CreateCond(void); |
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| 129 | |||
| 130 | /* Destroy a condition variable */ |
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| 131 | extern DECLSPEC void SDL_DestroyCond(SDL_cond *cond); |
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| 132 | |||
| 133 | /* Restart one of the threads that are waiting on the condition variable, |
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| 134 | returns 0 or -1 on error. |
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| 135 | */ |
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| 136 | extern DECLSPEC int SDL_CondSignal(SDL_cond *cond); |
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| 137 | |||
| 138 | /* Restart all threads that are waiting on the condition variable, |
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| 139 | returns 0 or -1 on error. |
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| 140 | */ |
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| 141 | extern DECLSPEC int SDL_CondBroadcast(SDL_cond *cond); |
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| 142 | |||
| 143 | /* Wait on the condition variable, unlocking the provided mutex. |
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| 144 | The mutex must be locked before entering this function! |
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| 145 | Returns 0 when it is signaled, or -1 on error. |
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| 146 | */ |
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| 147 | extern DECLSPEC int SDL_CondWait(SDL_cond *cond, SDL_mutex *mut); |
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| 148 | |||
| 149 | /* Waits for at most 'ms' milliseconds, and returns 0 if the condition |
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| 150 | variable is signaled, SDL_MUTEX_TIMEDOUT if the condition is not |
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| 151 | signaled in the allotted time, and -1 on error. |
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| 152 | On some platforms this function is implemented by looping with a delay |
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| 153 | of 1 ms, and so should be avoided if possible. |
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| 154 | */ |
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| 155 | extern DECLSPEC int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms); |
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| 156 | |||
| 157 | /* Ends C function definitions when using C++ */ |
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| 158 | #ifdef __cplusplus |
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| 159 | } |
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| 160 | #endif |
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| 161 | #include "close_code.h" |
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| 162 | |||
| 163 | #endif /* _SDL_mutex_h */ |