| /* |
| SDL - Simple DirectMedia Layer |
| Copyright (C) 1997-2010 Sam Lantinga |
| |
| This library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| This library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with this library; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| |
| Sam Lantinga |
| slouken@libsdl.org |
| */ |
| |
| #ifndef _SDL_mutex_h |
| #define _SDL_mutex_h |
| |
| /** |
| * \file SDL_mutex.h |
| * |
| * Functions to provide thread synchronization primitives. |
| */ |
| |
| #include "SDL_stdinc.h" |
| #include "SDL_error.h" |
| |
| #include "begin_code.h" |
| /* Set up for C function definitions, even when using C++ */ |
| #ifdef __cplusplus |
| /* *INDENT-OFF* */ |
| extern "C" { |
| /* *INDENT-ON* */ |
| #endif |
| |
| /** |
| * Synchronization functions which can time out return this value |
| * if they time out. |
| */ |
| #define SDL_MUTEX_TIMEDOUT 1 |
| |
| /** |
| * This is the timeout value which corresponds to never time out. |
| */ |
| #define SDL_MUTEX_MAXWAIT (~(Uint32)0) |
| |
| |
| /** |
| * \name Mutex functions |
| */ |
| /*@{*/ |
| |
| /* The SDL mutex structure, defined in SDL_mutex.c */ |
| struct SDL_mutex; |
| typedef struct SDL_mutex SDL_mutex; |
| |
| /** |
| * Create a mutex, initialized unlocked. |
| */ |
| extern DECLSPEC SDL_mutex *SDLCALL SDL_CreateMutex(void); |
| |
| /** |
| * Lock the mutex. |
| * |
| * \return 0, or -1 on error. |
| */ |
| #define SDL_LockMutex(m) SDL_mutexP(m) |
| extern DECLSPEC int SDLCALL SDL_mutexP(SDL_mutex * mutex); |
| |
| /** |
| * Unlock the mutex. |
| * |
| * \return 0, or -1 on error. |
| * |
| * \warning It is an error to unlock a mutex that has not been locked by |
| * the current thread, and doing so results in undefined behavior. |
| */ |
| #define SDL_UnlockMutex(m) SDL_mutexV(m) |
| extern DECLSPEC int SDLCALL SDL_mutexV(SDL_mutex * mutex); |
| |
| /** |
| * Destroy a mutex. |
| */ |
| extern DECLSPEC void SDLCALL SDL_DestroyMutex(SDL_mutex * mutex); |
| |
| /*@}*//*Mutex functions*/ |
| |
| |
| /** |
| * \name Semaphore functions |
| */ |
| /*@{*/ |
| |
| /* The SDL semaphore structure, defined in SDL_sem.c */ |
| struct SDL_semaphore; |
| typedef struct SDL_semaphore SDL_sem; |
| |
| /** |
| * Create a semaphore, initialized with value, returns NULL on failure. |
| */ |
| extern DECLSPEC SDL_sem *SDLCALL SDL_CreateSemaphore(Uint32 initial_value); |
| |
| /** |
| * Destroy a semaphore. |
| */ |
| extern DECLSPEC void SDLCALL SDL_DestroySemaphore(SDL_sem * sem); |
| |
| /** |
| * This function suspends the calling thread until the semaphore pointed |
| * to by \c sem has a positive count. It then atomically decreases the |
| * semaphore count. |
| */ |
| extern DECLSPEC int SDLCALL SDL_SemWait(SDL_sem * sem); |
| |
| /** |
| * Non-blocking variant of SDL_SemWait(). |
| * |
| * \return 0 if the wait succeeds, ::SDL_MUTEX_TIMEDOUT if the wait would |
| * block, and -1 on error. |
| */ |
| extern DECLSPEC int SDLCALL SDL_SemTryWait(SDL_sem * sem); |
| |
| /** |
| * Variant of SDL_SemWait() with a timeout in milliseconds. |
| * |
| * \return 0 if the wait succeeds, ::SDL_MUTEX_TIMEDOUT if the wait does not |
| * succeed in the allotted time, and -1 on error. |
| * |
| * \warning On some platforms this function is implemented by looping with a |
| * delay of 1 ms, and so should be avoided if possible. |
| */ |
| extern DECLSPEC int SDLCALL SDL_SemWaitTimeout(SDL_sem * sem, Uint32 ms); |
| |
| /** |
| * Atomically increases the semaphore's count (not blocking). |
| * |
| * \return 0, or -1 on error. |
| */ |
| extern DECLSPEC int SDLCALL SDL_SemPost(SDL_sem * sem); |
| |
| /** |
| * Returns the current count of the semaphore. |
| */ |
| extern DECLSPEC Uint32 SDLCALL SDL_SemValue(SDL_sem * sem); |
| |
| /*@}*//*Semaphore functions*/ |
| |
| |
| /** |
| * \name Condition variable functions |
| */ |
| /*@{*/ |
| |
| /* The SDL condition variable structure, defined in SDL_cond.c */ |
| struct SDL_cond; |
| typedef struct SDL_cond SDL_cond; |
| |
| /** |
| * Create a condition variable. |
| */ |
| extern DECLSPEC SDL_cond *SDLCALL SDL_CreateCond(void); |
| |
| /** |
| * Destroy a condition variable. |
| */ |
| extern DECLSPEC void SDLCALL SDL_DestroyCond(SDL_cond * cond); |
| |
| /** |
| * Restart one of the threads that are waiting on the condition variable. |
| * |
| * \return 0 or -1 on error. |
| */ |
| extern DECLSPEC int SDLCALL SDL_CondSignal(SDL_cond * cond); |
| |
| /** |
| * Restart all threads that are waiting on the condition variable. |
| * \return 0 or -1 on error. |
| */ |
| extern DECLSPEC int SDLCALL SDL_CondBroadcast(SDL_cond * cond); |
| |
| /** |
| * Wait on the condition variable, unlocking the provided mutex. |
| * |
| * \warning The mutex must be locked before entering this function! |
| * |
| * The mutex is re-locked once the condition variable is signaled. |
| * |
| * \return 0 when it is signaled, or -1 on error. |
| */ |
| extern DECLSPEC int SDLCALL SDL_CondWait(SDL_cond * cond, SDL_mutex * mut); |
| |
| /** |
| * Waits for at most \c ms milliseconds, and returns 0 if the condition |
| * variable is signaled, ::SDL_MUTEX_TIMEDOUT if the condition is not |
| * signaled in the allotted time, and -1 on error. |
| * |
| * \warning On some platforms this function is implemented by looping with a |
| * delay of 1 ms, and so should be avoided if possible. |
| */ |
| extern DECLSPEC int SDLCALL SDL_CondWaitTimeout(SDL_cond * cond, |
| SDL_mutex * mutex, Uint32 ms); |
| |
| /*@}*//*Condition variable functions*/ |
| |
| |
| /* Ends C function definitions when using C++ */ |
| #ifdef __cplusplus |
| /* *INDENT-OFF* */ |
| } |
| /* *INDENT-ON* */ |
| #endif |
| #include "close_code.h" |
| |
| #endif /* _SDL_mutex_h */ |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |