Ticket #6130: cvt1.c

#include <pthread.h>
#include <assert.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>

pthread_mutex_t mtx;
pthread_cond_t cv;

void mutex_lock()
{
        if (pthread_mutex_lock(&mtx) != 0)
                _exit(3);
}

void mutex_unlock()
{
        if (pthread_mutex_unlock(&mtx) != 0)
                _exit(3);
}

int main()
{
        if (0 != pthread_mutex_init(&mtx,0))
                return 1;
        if (0 != pthread_cond_init(&cv,0))
                return 2;

        while(1) {
                int i;
                for (i=0; i<3; ++i) {
                        mutex_lock();
                        const time_t wait_time = time(0)+1;
                        struct timespec tm;
                        tm.tv_sec = wait_time;
                        tm.tv_nsec = 0;
                        const int err = pthread_cond_timedwait(&cv, &mtx, &tm);
                        if (err != ETIMEDOUT) {
                                printf("error cond\n");
                                return 4;
                        }
                        const time_t end_time = time(0);
                        mutex_unlock();
                        if (end_time < wait_time) {
                                printf("wait:%lu wakeup:%lu\n", (long)wait_time, (long)end_time);
                                assert(!"early wakeup");
                        }
                        printf("OK\n");
                }
                const long s = random() % 100000;
                printf("switch, sleep %l ms\n", s);
                usleep(s);
        }
}