view src/thread/linux/SDL_syscond.c @ 641:df178851293b

Date: 28 Jun 2003 22:42:52 +0100 From: Alan Swanson Subject: Re: [SDL] New XFree 4.3 Video Mode Patch I have a wee amendment that moves the qsort in set_best_resolution to only occur after failing to find an exact match only. This would make absolutely sure we get a user set mode. While I've never had any problems for my normal resolutions (1280x1024, 1024x768, 800x600 & 640,480) while closely examining the output from qsort I've noticed it doesn't seem to sort the modes fully. These is one definite wrong at 1152x768 and a few that just look wrong to me. From a program (attached) I made to examine this more easily. X has sorted its mode list using the same method as ours (plus frequency), and our user modes get inserted without any other movement. On the patch I've made I've also changed cmpmodes to sort on vertical resolution and then horizontal. Ie vertical is now most significant bit.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 28 Jun 2003 21:52:26 +0000
parents f6ffac90895c
children b8d311d90021
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  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

#ifdef linux
/* Look to see if glibc is available, and if so, what version */
#include <features.h>

#if (__GLIBC__ == 2) && (__GLIBC_MINOR__ == 0)
#warning Working around a bug in glibc 2.0 pthreads
#undef SDL_USE_PTHREADS
/* The bug is actually a problem where threads are suspended, but don't
   wake up when the thread manager sends them a signal.  This is a problem
   with thread creation too, but it happens less often. :-/
   We avoid this by using System V IPC for mutexes.
 */
#endif /* glibc 2.0 */
#endif /* linux */

#ifdef SDL_USE_PTHREADS

#include <sys/time.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <pthread.h>

#include "SDL_error.h"
#include "SDL_thread.h"
#include "SDL_sysmutex_c.h"


#if defined(PTHREAD_NO_RECURSIVE_MUTEX) && !defined(__bsdi__)
#error You need to use the generic condition variable implementation
#endif

struct SDL_cond
{
	pthread_cond_t cond;
};

/* Create a condition variable */
SDL_cond * SDL_CreateCond(void)
{
	SDL_cond *cond;

	cond = (SDL_cond *) malloc(sizeof(SDL_cond));
	if ( cond ) {
		if ( pthread_cond_init(&cond->cond, NULL) < 0 ) {
			SDL_SetError("pthread_cond_init() failed");
			free(cond);
			cond = NULL;
		}
	}
	return(cond);
}

/* Destroy a condition variable */
void SDL_DestroyCond(SDL_cond *cond)
{
	if ( cond ) {
		pthread_cond_destroy(&cond->cond);
		free(cond);
	}
}

/* Restart one of the threads that are waiting on the condition variable */
int SDL_CondSignal(SDL_cond *cond)
{
	int retval;

	if ( ! cond ) {
		SDL_SetError("Passed a NULL condition variable");
		return -1;
	}

	retval = 0;
	if ( pthread_cond_signal(&cond->cond) != 0 ) {
		SDL_SetError("pthread_cond_signal() failed");
		retval = -1;
	}
	return retval;
}

/* Restart all threads that are waiting on the condition variable */
int SDL_CondBroadcast(SDL_cond *cond)
{
	int retval;

	if ( ! cond ) {
		SDL_SetError("Passed a NULL condition variable");
		return -1;
	}

	retval = 0;
	if ( pthread_cond_broadcast(&cond->cond) != 0 ) {
		SDL_SetError("pthread_cond_broadcast() failed");
		retval = -1;
	}
	return retval;
}

int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms)
{
	int retval;
	struct timeval delta;
	struct timespec abstime;

	if ( ! cond ) {
		SDL_SetError("Passed a NULL condition variable");
		return -1;
	}

	gettimeofday(&delta, NULL);

	abstime.tv_sec = delta.tv_sec + (ms/1000);
	abstime.tv_nsec = (delta.tv_usec + (ms%1000) * 1000) * 1000;
        if ( abstime.tv_nsec > 1000000000 ) {
          abstime.tv_sec += 1;
          abstime.tv_nsec -= 1000000000;
        }

  tryagain:
	retval = pthread_cond_timedwait(&cond->cond, &mutex->id, &abstime);
	switch (retval) {
	    case EINTR:
		goto tryagain;
		break;
	    case ETIMEDOUT:
		retval = SDL_MUTEX_TIMEDOUT;
		break;
	    case 0:
		break;
	    default:
		SDL_SetError("pthread_cond_timedwait() failed");
		retval = -1;
		break;
	}
	return retval;
}

/* Wait on the condition variable, unlocking the provided mutex.
   The mutex must be locked before entering this function!
 */
int SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex)
{
	int retval;

	if ( ! cond ) {
		SDL_SetError("Passed a NULL condition variable");
		return -1;
	}

	retval = 0;
	if ( pthread_cond_wait(&cond->cond, &mutex->id) != 0 ) {
		SDL_SetError("pthread_cond_wait() failed");
		retval = -1;
	}
	return retval;
}

#else /* Use semaphore implementation */

#include "generic/SDL_syscond.c"

#endif /* SDL_USE_PTHREADS */