view include/SDL_mutex.h @ 1180:bdcb8bb4c831

From: Tyler Montbriand <tsm@accesscomm.ca> To: sdl@libsdl.org Date: Fri, 30 Sep 2005 02:24:50 -0600 Subject: [SDL] WinCE timers, continued Here's a strange timer for Windows CE that doesn't ignore time across suspends. It uses GetSystemTime to keep the time continuous, and GetTicks to get finer-grained readings than 1 second. It detects the difference between the GetTicks time and GetSystemTime time on power-on to keep the error within one second max. It's not a patch on the current win32 timer code -- took one look at that and figured it had more than enough #ifdefs already. It's windows-ce specific. Another thing I've noticed is that the Windows CE 4.0 and newer API has functions warn processes about suspends. This is something SDL REALLY needs for audio in particular, because turning it off while it's playing causes anything that uses audio to hardlock the system on power-on. Unfortunately I don't have 4.0 to play with. :(
author Ryan C. Gordon <icculus@icculus.org>
date Tue, 22 Nov 2005 07:10:07 +0000
parents b8d311d90021
children 3bdcef7e1c90
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/*
    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_RCSID
static char rcsid =
 "@(#) $Id$";
#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 __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)


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* 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 */