/*
 * critical-section-bad.c
 */

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

#define NUM_CHILDREN 3
#define NUM_ITERATIONS 10
#define SLEEP_NSECS 50

void *child_func(void *data);

int
main(int argc, char *argv[])
{
    int i;
    pthread_t threads[NUM_CHILDREN];
    int thread_ids[NUM_CHILDREN];

    for(i=0; i<NUM_CHILDREN; i++) {
        thread_ids[i] = i;
        pthread_create(&threads[i], NULL, child_func, &thread_ids[i]);
    }

    for(i=0; i<NUM_CHILDREN; i++) {
        pthread_join(threads[i], NULL);
    }
}

void *
child_func(void *data)
{
    int i;
    int id = *((int *) data);
    struct timespec ts;

    ts.tv_sec = 0;
    ts.tv_nsec = SLEEP_NSECS;

    printf("thread %d entering critical section\n", id);
    for(i=0; i<NUM_ITERATIONS; i++) {
        printf("%d\n", id);
        nanosleep(&ts, NULL);
    }
    printf("thread %d leaving critical section\n", id);

    return NULL;
}