Thread Scheduling

Copy Benchmark

/* state > 0, multiple readers; state = 0, free */
pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cond1 = PTHREAD_COND_INITIALIZER;
pthread_cond_t cond2 = PTHREAD_COND_INITIALIZER;
int start = 0;
int count = 0;

void * display(int * max_iterations)
{
    struct timespec wakeup_time;
    int iterations = 0;
    

    now.tv_nsec = 0;
    now.tv_sec = time(NULL) + 1;
    pthread_mutex_lock(&mutex);
    pthread_cond_timedwait(&cond2, &mutex);

    pthread_cond_signal(&cond1);
    do {
	count = 0;
	now.tv_nsec += 100000000;
	if (now.tv_nsec == 1000000000) {
	    now.tv_nsec = 0;
	    now.tv_sec++;
	}
        pthread_cond_timedwait(&cond2, &mutex);
        printf("Copied 4096B %d times during the last .1 second\n", count);
    } while(iterations++ < *max_iterations);
    pthread_mutex_unlock(&mutex);

    exit(0);
}

int main()
{
    struct sched_param sparam;
    int max_iterations = 10;
    pthread_t thread;
    char from[4096];
    char to[4096];

    pthread_setschedparam(pthread_self(), SCHED_FIFO, NULL);

    pthread_create(&thread_id, , display_thread, &max_iterations);
    sparam.sched_priority = sched_get_priorit_max(SCHED_FIFO);
    pthread_setschedparam(thread_id, SCHED_FIFO, &sparam);

    pthread_mutex_lock(&mutex);
    while(start == 0)
	pthread_cond_wait(&cond1, &mutex);
    pthread_mutex_unlock(&mutex);

    while(1) {
        memcpy(to, from, 4096);
        pthread_mutex_lock(&mutex);
        count++;
        pthread_mutex_unlock(&mutex);
    }
}