view test/testlock.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 0d1b16ee0bca
children
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line source


/* Test the thread and mutex locking functions 
   Also exercises the system's signal/thread interaction
*/

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

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

static SDL_mutex *mutex = NULL;
static SDL_threadID mainthread;
static SDL_Thread *threads[6];
static volatile int doterminate = 0;

/*
 * SDL_Quit() shouldn't be used with atexit() directly because
 *  calling conventions may differ...
 */
static void
SDL_Quit_Wrapper(void)
{
    SDL_Quit();
}

void
printid(void)
{
    printf("Process %lu:  exiting\n", SDL_ThreadID());
}

void
terminate(int sig)
{
    signal(SIGINT, terminate);
    doterminate = 1;
}

void
closemutex(int sig)
{
    SDL_threadID id = SDL_ThreadID();
    int i;
    printf("Process %lu:  Cleaning up...\n", id == mainthread ? 0 : id);
    doterminate = 1;
    for (i = 0; i < 6; ++i)
        SDL_WaitThread(threads[i], NULL);
    SDL_DestroyMutex(mutex);
    exit(sig);
}

int SDLCALL
Run(void *data)
{
    if (SDL_ThreadID() == mainthread)
        signal(SIGTERM, closemutex);
    while (!doterminate) {
        printf("Process %lu ready to work\n", SDL_ThreadID());
        if (SDL_mutexP(mutex) < 0) {
            fprintf(stderr, "Couldn't lock mutex: %s", SDL_GetError());
            exit(1);
        }
        printf("Process %lu, working!\n", SDL_ThreadID());
        SDL_Delay(1 * 1000);
        printf("Process %lu, done!\n", SDL_ThreadID());
        if (SDL_mutexV(mutex) < 0) {
            fprintf(stderr, "Couldn't unlock mutex: %s", SDL_GetError());
            exit(1);
        }
        /* If this sleep isn't done, then threads may starve */
        SDL_Delay(10);
    }
    if (SDL_ThreadID() == mainthread && doterminate) {
        printf("Process %lu:  raising SIGTERM\n", SDL_ThreadID());
        raise(SIGTERM);
    }
    return (0);
}

int
main(int argc, char *argv[])
{
    int i;
    int maxproc = 6;

    /* Load the SDL library */
    if (SDL_Init(0) < 0) {
        fprintf(stderr, "%s\n", SDL_GetError());
        exit(1);
    }
    atexit(SDL_Quit_Wrapper);

    if ((mutex = SDL_CreateMutex()) == NULL) {
        fprintf(stderr, "Couldn't create mutex: %s\n", SDL_GetError());
        exit(1);
    }

    mainthread = SDL_ThreadID();
    printf("Main thread: %lu\n", mainthread);
    atexit(printid);
    for (i = 0; i < maxproc; ++i) {
        if ((threads[i] = SDL_CreateThread(Run, NULL)) == NULL)
            fprintf(stderr, "Couldn't create thread!\n");
    }
    signal(SIGINT, terminate);
    Run(NULL);

    return (0);                 /* Never reached */
}