+
−/*
+
−    SDL - Simple DirectMedia Layer
+
−    Copyright (C) 1997-2012 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
+
− *
+
− *  @note These are independent of the other SDL routines.
+
− */
+
−
+
−#include "SDL_stdinc.h"
+
−#include "SDL_error.h"
+
−
+
−#include "begin_code.h"
+
−/* Set up for C function definitions, even when using C++ */
+
−#ifdef __cplusplus
+
−extern "C" {
+
−#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);
+
−
+
−#define SDL_LockMutex(m)    SDL_mutexP(m)
+
−/** Lock the mutex
+
− *  @return 0, or -1 on error
+
− */
+
−extern DECLSPEC int SDLCALL SDL_mutexP(SDL_mutex *mutex);
+
−
+
−#define SDL_UnlockMutex(m)  SDL_mutexV(m)
+
−/** Unlock the mutex
+
− *  @return 0, or -1 on error
+
− *
+
− *  It is an error to unlock a mutex that has not been locked by
+
− *  the current thread, and doing so results in undefined behavior.
+
− */
+
−extern DECLSPEC int SDLCALL SDL_mutexV(SDL_mutex *mutex);
+
−
+
−/** Destroy a mutex */
+
−extern DECLSPEC void SDLCALL SDL_DestroyMutex(SDL_mutex *mutex);
+
−
+
−/*@}*/
+
−
+
−/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
−/** @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 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, returns 0 if
+
− *  the wait succeeds, SDL_MUTEX_TIMEDOUT if the wait does not succeed in
+
− *  the allotted time, and -1 on error.
+
− *
+
− *  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);
+
−
+
−/*@}*/
+
−
+
−/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
−/** @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.
+
− *  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 '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.
+
− *  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);
+
−
+
−/*@}*/
+
−
+
−/* Ends C function definitions when using C++ */
+
−#ifdef __cplusplus
+
−}
+
−#endif
+
−#include "close_code.h"
+
−
+
−#endif /* _SDL_mutex_h */
+
−