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177 lines
5.7 KiB
177 lines
5.7 KiB
/* |
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SDL - Simple DirectMedia Layer |
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Copyright (C) 1997-2009 Sam Lantinga |
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This library is free software; you can redistribute it and/or |
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modify it under the terms of the GNU Lesser General Public |
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License as published by the Free Software Foundation; either |
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version 2.1 of the License, or (at your option) any later version. |
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This library is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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Lesser General Public License for more details. |
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You should have received a copy of the GNU Lesser General Public |
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License along with this library; if not, write to the Free Software |
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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Sam Lantinga |
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slouken@libsdl.org |
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*/ |
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#ifndef _SDL_mutex_h |
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#define _SDL_mutex_h |
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/** @file SDL_mutex.h |
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* Functions to provide thread synchronization primitives |
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* |
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* @note These are independent of the other SDL routines. |
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*/ |
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#include "SDL_stdinc.h" |
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#include "SDL_error.h" |
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#include "begin_code.h" |
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/* Set up for C function definitions, even when using C++ */ |
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#ifdef __cplusplus |
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extern "C" { |
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#endif |
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/** Synchronization functions which can time out return this value |
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* if they time out. |
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*/ |
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#define SDL_MUTEX_TIMEDOUT 1 |
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/** This is the timeout value which corresponds to never time out */ |
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#define SDL_MUTEX_MAXWAIT (~(Uint32)0) |
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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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/** @name Mutex functions */ /*@{*/ |
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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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/** The SDL mutex structure, defined in SDL_mutex.c */ |
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struct SDL_mutex; |
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typedef struct SDL_mutex SDL_mutex; |
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/** Create a mutex, initialized unlocked */ |
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extern DECLSPEC SDL_mutex * SDLCALL SDL_CreateMutex(void); |
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#define SDL_LockMutex(m) SDL_mutexP(m) |
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/** Lock the mutex |
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* @return 0, or -1 on error |
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*/ |
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extern DECLSPEC int SDLCALL SDL_mutexP(SDL_mutex *mutex); |
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#define SDL_UnlockMutex(m) SDL_mutexV(m) |
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/** Unlock the mutex |
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* @return 0, or -1 on error |
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* |
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* It is an error to unlock a mutex that has not been locked by |
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* the current thread, and doing so results in undefined behavior. |
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*/ |
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extern DECLSPEC int SDLCALL SDL_mutexV(SDL_mutex *mutex); |
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/** Destroy a mutex */ |
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extern DECLSPEC void SDLCALL SDL_DestroyMutex(SDL_mutex *mutex); |
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/*@}*/ |
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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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/** @name Semaphore functions */ /*@{*/ |
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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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/** The SDL semaphore structure, defined in SDL_sem.c */ |
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struct SDL_semaphore; |
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typedef struct SDL_semaphore SDL_sem; |
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/** Create a semaphore, initialized with value, returns NULL on failure. */ |
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extern DECLSPEC SDL_sem * SDLCALL SDL_CreateSemaphore(Uint32 initial_value); |
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/** Destroy a semaphore */ |
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extern DECLSPEC void SDLCALL SDL_DestroySemaphore(SDL_sem *sem); |
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/** |
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* This function suspends the calling thread until the semaphore pointed |
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* to by sem has a positive count. It then atomically decreases the semaphore |
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* count. |
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*/ |
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extern DECLSPEC int SDLCALL SDL_SemWait(SDL_sem *sem); |
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/** Non-blocking variant of SDL_SemWait(). |
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* @return 0 if the wait succeeds, |
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* SDL_MUTEX_TIMEDOUT if the wait would block, and -1 on error. |
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*/ |
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extern DECLSPEC int SDLCALL SDL_SemTryWait(SDL_sem *sem); |
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/** Variant of SDL_SemWait() with a timeout in milliseconds, returns 0 if |
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* the wait succeeds, SDL_MUTEX_TIMEDOUT if the wait does not succeed in |
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* the allotted time, and -1 on error. |
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* |
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* On some platforms this function is implemented by looping with a delay |
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* of 1 ms, and so should be avoided if possible. |
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*/ |
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extern DECLSPEC int SDLCALL SDL_SemWaitTimeout(SDL_sem *sem, Uint32 ms); |
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/** Atomically increases the semaphore's count (not blocking). |
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* @return 0, or -1 on error. |
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*/ |
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extern DECLSPEC int SDLCALL SDL_SemPost(SDL_sem *sem); |
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/** Returns the current count of the semaphore */ |
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extern DECLSPEC Uint32 SDLCALL SDL_SemValue(SDL_sem *sem); |
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/*@}*/ |
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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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/** @name Condition_variable_functions */ /*@{*/ |
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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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/*@{*/ |
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/** The SDL condition variable structure, defined in SDL_cond.c */ |
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struct SDL_cond; |
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typedef struct SDL_cond SDL_cond; |
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/*@}*/ |
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/** Create a condition variable */ |
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extern DECLSPEC SDL_cond * SDLCALL SDL_CreateCond(void); |
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/** Destroy a condition variable */ |
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extern DECLSPEC void SDLCALL SDL_DestroyCond(SDL_cond *cond); |
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/** Restart one of the threads that are waiting on the condition variable, |
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* @return 0 or -1 on error. |
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*/ |
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extern DECLSPEC int SDLCALL SDL_CondSignal(SDL_cond *cond); |
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/** Restart all threads that are waiting on the condition variable, |
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* @return 0 or -1 on error. |
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*/ |
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extern DECLSPEC int SDLCALL SDL_CondBroadcast(SDL_cond *cond); |
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/** Wait on the condition variable, unlocking the provided mutex. |
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* The mutex must be locked before entering this function! |
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* The mutex is re-locked once the condition variable is signaled. |
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* @return 0 when it is signaled, or -1 on error. |
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*/ |
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extern DECLSPEC int SDLCALL SDL_CondWait(SDL_cond *cond, SDL_mutex *mut); |
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/** Waits for at most 'ms' milliseconds, and returns 0 if the condition |
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* variable is signaled, SDL_MUTEX_TIMEDOUT if the condition is not |
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* signaled in the allotted time, and -1 on error. |
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* On some platforms this function is implemented by looping with a delay |
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* of 1 ms, and so should be avoided if possible. |
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*/ |
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extern DECLSPEC int SDLCALL SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms); |
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/*@}*/ |
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/* Ends C function definitions when using C++ */ |
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#ifdef __cplusplus |
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} |
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#endif |
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#include "close_code.h" |
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#endif /* _SDL_mutex_h */ |
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