view test/testsem.c @ 998:0e6627072f7a

Date: Wed, 24 Nov 2004 01:25:48 +0100 From: Stephane Marchesin Subject: Re: [SDL] Problem compiling SDL 1.2.7 - there is a bug that was introduced in the kernel headers for 2.6.9 which is fixed in 2.6.10. This bug *will* byte when compiling the cdrom subsystem. A patch that works around this bug is attached. Note that users affected are not those running 2.6.9, but those using the 2.6.9 kernel headers for their system (i.e. whose libc is built against 2.6.9 headers).
author Sam Lantinga <slouken@libsdl.org>
date Tue, 30 Nov 2004 14:45:08 +0000
parents 74212992fb08
children be9c9c8f6d53
line wrap: on
line source


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

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

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

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

	/* Load the SDL library */
	if ( SDL_Init(0) < 0 ) {
		fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());
		exit(1);
	}
	atexit(SDL_Quit);
	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);
	return(0);
}