Attachment 146162 Details for Bug 192926 – test case

test case

yield_noop.c (text/x-c), 1.97 KB, created by eric on 2014-08-22 18:24:46 UTC

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Creator: eric

Created: 2014-08-22 18:24:46 UTC

Size: 1.97 KB

patch

obsolete

>// cc -lpthread -o yield_noop yield_noop.c
>//
>// failure: worker is NOT making progress
>// success: worker is making progress
>
>#include <sys/cdefs.h>
>#include <sys/param.h>
>#include <sys/cpuset.h>
>
>#include <err.h>
>#include <pthread.h>
>#include <pthread_np.h>
>#include <stdio.h>
>#include <unistd.h>
>
>static unsigned int worker_counter = 0;
>
>static void *
>yielding_thread_func(void *arg __unused)
>{
>    for (;;)
>        pthread_yield();
>
>    return (NULL);
>}
>
>static void *
>worker_thread_func(void *arg __unused)
>{
>    char dot = '.';
>
>    for (;;) {
>        sleep(1);
>        write(STDERR_FILENO, &dot, sizeof(dot));
>        ++worker_counter;
>    }
>
>    return (NULL);
>}
>
>int
>main(int argc __unused, char *argv[] __unused)
>{
>    int error;
>    pthread_t yielding_thread, worker_thread;
>    pthread_attr_t thread_attr;
>    cpuset_t cpuset;
>    const unsigned int sleep_time = 4;
>
>    error = pthread_attr_init(&thread_attr);
>    if (error)
>        errc(1, error, "pthread_attr_init");
>
>    error = pthread_attr_setinheritsched(&thread_attr, PTHREAD_EXPLICIT_SCHED);
>    if (error)
>        errc(1, error, "pthread_attr_setinheritsched");
>
>    error = pthread_attr_setschedpolicy(&thread_attr, SCHED_FIFO);
>    if (error)
>        errc(1, error, "pthread_attr_setschedpolicy");
>
>    // Bind both threads to the same CPU.
>    CPU_ZERO(&cpuset);
>    CPU_SET(0, &cpuset);
>
>    error = pthread_attr_setaffinity_np(&thread_attr, sizeof(cpuset), &cpuset);
>    if (error)
>        errc(1, error, "pthread_attr_setaffinity_np");
>
>    error = pthread_create(&yielding_thread, &thread_attr, yielding_thread_func, NULL);
>    if (error)
>        errc(1, error, "pthread_create(yielding_thread)");
>
>    error = pthread_create(&worker_thread, &thread_attr, worker_thread_func, NULL);
>    if (error)
>        errc(1, error, "pthread_create(worker_thread)");
>
>    sleep(sleep_time);
>    printf("worker is%s making progress: %d\n",
>           (worker_counter >= sleep_time - 1) ? "" : " NOT",
>           worker_counter);
>
>    return (0);
>}

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Attachments on bug 192926: 146161 | 146162