Test POSIX thread rwlock

rw_lock_test.c

#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <pthread.h>
#include <errno.h>
#include <string.h>

#define ERROR_PRINTF(fmt, args...) { \
    fprintf(stderr, fmt, args); \
    _exit(EXIT_FAILURE); \
}

pthread_rwlock_t rwlock;

void *rw_rdlock_test(void *_payload) {
    int i;
    long test_id = (long) _payload;
    for (i = 0; i < 10; ++i) {
        if (pthread_rwlock_rdlock(&rwlock))
            ERROR_PRINTF("Failed to lock %ld for read: %s\n", test_id, strerror(errno));
        printf("Lock %ld for read is going to sleep ...\n", test_id);
        sleep(5);
        printf("Lock %ld for read is awake\n", test_id);
        if (pthread_rwlock_unlock(&rwlock))
            ERROR_PRINTF("Failed to unlock %ld for read: %s\n", test_id, strerror(errno));
    }
    return NULL;
}

void *rw_wrlock_test(void *_payload) {
    int i;
    long test_id = (long) _payload;
    for (i = 0; i < 10; ++i) {
        if (pthread_rwlock_wrlock(&rwlock))
            ERROR_PRINTF("Failed to lock %ld for write: %s\n", test_id, strerror(errno));
        printf("Lock %ld for write is going to sleep ...\n", test_id);
        sleep(5);
        printf("Lock %ld for write is awake\n", test_id);
        if (pthread_rwlock_unlock(&rwlock))
            ERROR_PRINTF("Failed to unlock %ld for write: %s\n", test_id, strerror(errno));
    }
    return NULL;
}

int main(int argc, char const *argv[]) {
    long i;
    pthread_t threads[10];
    pthread_rwlockattr_t attr;

    if (pthread_rwlockattr_init(&attr))
        ERROR_PRINTF("Failed to initialize rwlockattr: %s\n", strerror(errno));
    if (pthread_rwlockattr_setkind_np(&attr, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP))
        ERROR_PRINTF("Failed to setkind np for rwlockattr: %s\n", strerror(errno));
    if (pthread_rwlock_init(&rwlock, &attr))
        ERROR_PRINTF("Failed to initialize rwlock: %s\n", strerror(errno));
    if (pthread_rwlockattr_destroy(&attr))
        ERROR_PRINTF("Failed to destroy rwlockattr: %s\n", strerror(errno));

    for (i = 0; i < 5; ++i) {
        if (pthread_create(&threads[i], NULL, rw_rdlock_test, (void *) i))
            ERROR_PRINTF("Failed to create thread %ld: %s\n", i, strerror(errno));
    }
    for (; i < 10; ++i) {
        if (pthread_create(&threads[i], NULL, rw_wrlock_test, (void *) i))
            ERROR_PRINTF("Failed to create thread %ld: %s\n", i, strerror(errno));
    }
    for (i = 0; i < 10; ++i) {
        if (pthread_join(threads[i], NULL))
            ERROR_PRINTF("Failed to join thread %ld: %s\n", i, strerror(errno));
    }

    if (pthread_rwlock_destroy(&rwlock))
        ERROR_PRINTF("Failed to destroy rwlock: %s\n", strerror(errno));
    return 0;
}