view test/torturethread.c @ 3696:47d923feedb0

Fixed bug #935 Patrice Mandin Hello, I originally added pth support for threads in SDL 1.2 because on the Atari platform we did not have any thread library. I think pth support could be removed from SDL 1.3 for two reasons: - Atari platform removed - pth does not provides real (preemptive) threads, because it is user space, and expect the application to call one of its function to give CPU to another thread. So it is not exactly useful for applications, that expect threads to run simultaneously.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Jan 2010 20:47:20 +0000
parents c121d94672cb
children
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line source


/* Simple test of the SDL threading code */

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

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

#define NUMTHREADS 10

static char volatile time_for_threads_to_die[NUMTHREADS];

/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
static void
quit(int rc)
{
    SDL_Quit();
    exit(rc);
}

int SDLCALL
SubThreadFunc(void *data)
{
    while (!*(int volatile *) data) {
        ;                       /*SDL_Delay(10); *//* do nothing */
    }
    return 0;
}

int SDLCALL
ThreadFunc(void *data)
{
    SDL_Thread *sub_threads[NUMTHREADS];
    int flags[NUMTHREADS];
    int i;
    int tid = (int) (uintptr_t) data;

    fprintf(stderr, "Creating Thread %d\n", tid);

    for (i = 0; i < NUMTHREADS; i++) {
        flags[i] = 0;
        sub_threads[i] = SDL_CreateThread(SubThreadFunc, &flags[i]);
    }

    printf("Thread '%d' waiting for signal\n", tid);
    while (time_for_threads_to_die[tid] != 1) {
        ;                       /* do nothing */
    }

    printf("Thread '%d' sending signals to subthreads\n", tid);
    for (i = 0; i < NUMTHREADS; i++) {
        flags[i] = 1;
        SDL_WaitThread(sub_threads[i], NULL);
    }

    printf("Thread '%d' exiting!\n", tid);

    return 0;
}

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

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

    signal(SIGSEGV, SIG_DFL);
    for (i = 0; i < NUMTHREADS; i++) {
        time_for_threads_to_die[i] = 0;
        threads[i] = SDL_CreateThread(ThreadFunc, (void *) (uintptr_t) i);

        if (threads[i] == NULL) {
            fprintf(stderr, "Couldn't create thread: %s\n", SDL_GetError());
            quit(1);
        }
    }

    for (i = 0; i < NUMTHREADS; i++) {
        time_for_threads_to_die[i] = 1;
    }

    for (i = 0; i < NUMTHREADS; i++) {
        SDL_WaitThread(threads[i], NULL);
    }
    SDL_Quit();
    return (0);
}