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mirror of https://github.com/joel16/SDL2.git synced 2024-12-14 14:59:43 +00:00
SDL2/include/SDL_mutex.h
Sam Lantinga 1cbfd5b6e0 Partial fix for bug
Header file update from Ken for improved doxygen output

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%404127
2009-10-19 13:31:58 +00:00

224 lines
5.7 KiB
C

/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997-2009 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: */