view src/thread/win32/SDL_syssem.c @ 1029:f87f87efd45a

Date: Mon, 17 Jan 2005 20:54:50 +0200 From: Ville [snip] Subject: [PATCH] SDL/DirectFB: remove Matrox CRTC2 flicker filter Hi, This patch removes the flicker filter option from the DirectFB backend's Matrox CRTC2 code in SDL. I will be removing the option from DirectFB (because it doesn't actually work) and that would cause the SDL code to fail without this fix. I was going to send this to some SDL list directly but libsdl.org is down so I'm not sure what if any lists there are. Thomas Jarosch (the guy who wrote the code) said you would accept SDL patches. Let me know if I should send this somewhere else. -- Ville Syrj�l� syrjala _at sci.fi http://www.sci.fi/~syrjala/
author Ryan C. Gordon <icculus@icculus.org>
date Mon, 17 Jan 2005 19:38:28 +0000
parents b8d311d90021
children c9b51268668f
line wrap: on
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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

/* Semaphore functions using the Win32 API */

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>

#include "SDL_error.h"
#include "SDL_thread.h"
#if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
#include "win_ce_semaphore.h"
#endif


struct SDL_semaphore {
#if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
	SYNCHHANDLE id;
#else
	HANDLE id;
#endif
	Uint32 volatile count;
};


/* Create a semaphore */
SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
{
	SDL_sem *sem;

	/* Allocate sem memory */
	sem = (SDL_sem *)malloc(sizeof(*sem));
	if ( sem ) {
		/* Create the semaphore, with max value 32K */
#if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
		sem->id = CreateSemaphoreCE(NULL, initial_value, 32*1024, NULL);
#else
		sem->id = CreateSemaphore(NULL, initial_value, 32*1024, NULL);
#endif
		sem->count = initial_value;
		if ( ! sem->id ) {
			SDL_SetError("Couldn't create semaphore");
			free(sem);
			sem = NULL;
		}
	} else {
		SDL_OutOfMemory();
	}
	return(sem);
}

/* Free the semaphore */
void SDL_DestroySemaphore(SDL_sem *sem)
{
	if ( sem ) {
		if ( sem->id ) {
#if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
			CloseSynchHandle(sem->id);
#else
			CloseHandle(sem->id);
#endif
			sem->id = 0;
		}
		free(sem);
	}
}

int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
{
	int retval;
	DWORD dwMilliseconds;

	if ( ! sem ) {
		SDL_SetError("Passed a NULL sem");
		return -1;
	}

	if ( timeout == SDL_MUTEX_MAXWAIT ) {
		dwMilliseconds = INFINITE;
	} else {
		dwMilliseconds = (DWORD)timeout;
	}
#if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
	switch (WaitForSemaphoreCE(sem->id, dwMilliseconds)) {
#else
	switch (WaitForSingleObject(sem->id, dwMilliseconds)) {
#endif
	    case WAIT_OBJECT_0:
		--sem->count;
		retval = 0;
		break;
	    case WAIT_TIMEOUT:
		retval = SDL_MUTEX_TIMEDOUT;
		break;
	    default:
		SDL_SetError("WaitForSingleObject() failed");
		retval = -1;
		break;
	}
	return retval;
}

int SDL_SemTryWait(SDL_sem *sem)
{
	return SDL_SemWaitTimeout(sem, 0);
}

int SDL_SemWait(SDL_sem *sem)
{
	return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);
}

/* Returns the current count of the semaphore */
Uint32 SDL_SemValue(SDL_sem *sem)
{
	if ( ! sem ) {
		SDL_SetError("Passed a NULL sem");
		return 0;
	}
	return sem->count;
}

int SDL_SemPost(SDL_sem *sem)
{
	if ( ! sem ) {
		SDL_SetError("Passed a NULL sem");
		return -1;
	}
	/* Increase the counter in the first place, because
	 * after a successful release the semaphore may
	 * immediately get destroyed by another thread which
	 * is waiting for this semaphore.
	 */
	++sem->count;
#if defined(_WIN32_WCE) && (_WIN32_WCE < 300)
	if ( ReleaseSemaphoreCE(sem->id, 1, NULL) == FALSE ) {
#else
	if ( ReleaseSemaphore(sem->id, 1, NULL) == FALSE ) {
#endif
		--sem->count;	/* restore */
		SDL_SetError("ReleaseSemaphore() failed");
		return -1;
	}
	return 0;
}