/*    SDL - Simple DirectMedia Layer    Copyright (C) 1997-2004 Sam Lantinga    This library is free software; you can redistribute it and/or    modify it under the terms of the GNU Library General Public    License as published by the Free Software Foundation; either    version 2 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    Library General Public License for more details.    You should have received a copy of the GNU Library General Public    License along with this library; if not, write to the Free    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA    Sam Lantinga    slouken@libsdl.org*/#ifdef SAVE_RCSIDstatic char rcsid = "@(#) $Id: SDL_mutex.h,v 1.7 2004/01/04 16:49:07 slouken Exp $";#endif#ifndef _SDL_mutex_h#define _SDL_mutex_h/* Functions to provide thread synchronization primitives	These are independent of the other SDL routines.*/#include "SDL_main.h"#include "SDL_types.h"#include "begin_code.h"/* Set up for C function definitions, even when using C++ */#ifdef __cplusplusextern "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)/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *//* 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  (Returns 0, or -1 on error) */#define SDL_LockMutex(m)	SDL_mutexP(m)extern DECLSPEC int SDLCALL SDL_mutexP(SDL_mutex *mutex);/* Unlock the mutex  (Returns 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. */#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);/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *//* 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(), returns 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), returns 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);/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *//* 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,   returns 0 or -1 on error. */extern DECLSPEC int SDLCALL SDL_CondSignal(SDL_cond *cond);/* Restart all threads that are waiting on the condition variable,   returns 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!   Returns 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 */