#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <pthread.h>

void check(int error) {
    if (error != 0) {
        fprintf(stderr, "Error: %s\n", strerror(error));
        exit(EXIT_FAILURE);
    }
}

void* print1(void* par) {
    struct timespec ts = {0, 10000000};
    int i;
    for (i = 0; i < 10; i++) {
        nanosleep(&ts, NULL);
        printf("print1\n");
    }
    return NULL;
}

void* print2(void* par) {
    struct timespec ts = {0, 20000000};
    int i;
    for (i = 0; i < 10; i++) {
        nanosleep(&ts, NULL);
        printf("print2\n");
    }
    return NULL;
}

int main(void) {
    pthread_t t1, t2;

    check( pthread_create(&t1, NULL, &print1, NULL) );
    check( pthread_create(&t2, NULL, &print2, NULL) );

    check( pthread_join(t1, NULL) );
    check( pthread_join(t2, NULL) );

    return EXIT_SUCCESS;
}