view test/testsem.c @ 5282:8e421890cdb8

Fixed bug #1117 There's a new event that's always sent when the window changes size, and that event is what the renderers listen for to determine if they need to rebind their context.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 12 Feb 2011 19:02:14 -0800
parents d547877e355e
children
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 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;
}

static void
TestWaitTimeout(void)
{
    Uint32 start_ticks;
    Uint32 end_ticks;
    Uint32 duration;

    sem = SDL_CreateSemaphore(0);
    printf("Waiting 2 seconds on semaphore\n");

    start_ticks = SDL_GetTicks();
    SDL_SemWaitTimeout(sem, 2000);
    end_ticks = SDL_GetTicks();

    duration = end_ticks - start_ticks;

    /* Accept a little offset in the effective wait */
    if (duration > 1900 && duration < 2050)
        printf("Wait done.\n");
    else
        fprintf(stderr, "Wait took %d milliseconds\n", duration);
}

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);

    TestWaitTimeout();

    SDL_Quit();
    return (0);
}