#include <sys/types.h>
#include <sys/time.h>
#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include <pthread.h>
#include <stdlib.h>

#define NTHREAD 4
#define NTRY    50000

void *
start(void *dummy)
{
        int i;
        struct timespec ts0, ts1;

        printf("%d Starting\n", (int)getthrid());
        clock_gettime(CLOCK_MONOTONIC, &ts0);

        for (i = 0; i < NTRY; i++) {
                clock_gettime(CLOCK_MONOTONIC, &ts1);
                if (timespeccmp(&ts0, &ts1, <=)) {
                        ts0 = ts1;
                        continue;
                }
                printf("%d Back %lld.%09lu => %lld.%09lu\n",
                    (int)getthrid(), ts0.tv_sec, ts0.tv_nsec, ts1.tv_sec,
                    ts1.tv_nsec);
                break;
        }
        printf("%d Stopped\n", (int)getthrid());

        return (NULL);
}

int
main(int argc, char *argv[])
{
        int i, n = NTHREAD;
        pthread_t *threads;

        threads = calloc(n, sizeof(pthread_t));

        for (i = 0; i < n; i++)
                pthread_create(&threads[i], NULL, start, NULL);
        for (i = 0; i < n; i++)
                pthread_join(threads[i], NULL);

}