view test/testsem.c @ 4207:a673f44949d6 SDL-1.2

Fixed bug #562 this patch by Diego Pettenò <flameeyes@gentoo.org> for SDL-1.2: The attached patch applies over latest ~arch SDL version, and allows to use the xinerama support to launch an application full screened on the head "0". The SDL_VIDEO_FULLSCREEN_HEAD environment variable sets the head on which the full screen will be displayed, but if you set it to 0, the code simply ignores it as unset. My patch changes the unset value to -1, so that the 0 value can be used correctly. Without this, trying to get fullscreen on head 0 would get the same result than not having xinerama enabled at all. http://sources.gentoo.org/media-libs/libsdl/files/libsdl-1.2.11-xinerama-head-0.patch SDL-1.3 doesnt seem to have any code like this, but it's still good for SDL-1.2
author Sam Lantinga <slouken@libsdl.org>
date Mon, 21 Sep 2009 07:20:51 +0000
parents 290b5baf2fca
children 782fd950bd46 c121d94672cb 99acf3d856cb
line wrap: on
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/* Simple test of the SDL semaphore code */

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

#include "SDL.h"
#include "SDL_thread.h"

#define NUM_THREADS 10

static SDL_sem *sem;
int alive = 1;

int SDLCALL ThreadFunc(void *data)
{
	int threadnum = (int)(uintptr_t)data;
	while ( alive ) {
		SDL_SemWait(sem);
		fprintf(stderr, "Thread number %d has got the semaphore (value = %d)!\n", threadnum, SDL_SemValue(sem));
		SDL_Delay(200);
		SDL_SemPost(sem);
		fprintf(stderr, "Thread number %d has released the semaphore (value = %d)!\n", threadnum, SDL_SemValue(sem));
		SDL_Delay(1); /* For the scheduler */
	}
	printf("Thread number %d exiting.\n", threadnum);
	return 0;
}

static void killed(int sig)
{
	alive = 0;
}

int main(int argc, char **argv)
{
	SDL_Thread *threads[NUM_THREADS];
	uintptr_t i;
	int init_sem;

	if(argc < 2) {
		fprintf(stderr,"Usage: %s init_value\n", argv[0]);
		return(1);
	}

	/* Load the SDL library */
	if ( SDL_Init(0) < 0 ) {
		fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());
		return(1);
	}
	signal(SIGTERM, killed);
	signal(SIGINT, killed);
	
	init_sem = atoi(argv[1]);
	sem = SDL_CreateSemaphore(init_sem);
	
	printf("Running %d threads, semaphore value = %d\n", NUM_THREADS, init_sem);
	/* Create all the threads */
	for( i = 0; i < NUM_THREADS; ++i ) {
		threads[i] = SDL_CreateThread(ThreadFunc, (void*)i);
	}

	/* Wait 10 seconds */
	SDL_Delay(10 * 1000);

	/* Wait for all threads to finish */
	printf("Waiting for threads to finish\n");
	alive = 0;
	for( i = 0; i < NUM_THREADS; ++i ) {
		SDL_WaitThread(threads[i], NULL);
	}
	printf("Finished waiting for threads\n");

	SDL_DestroySemaphore(sem);
	SDL_Quit();
	return(0);
}