#define _XOPEN_SOURCE 600

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

static pthread_mutex_t	mutex;
static pthread_cond_t	cond;
static unsigned int		count = 0;


void *thread1(void *dummy)
{

	int					ret;
	struct timespec		req, res;

	req.tv_sec  = 1;
	req.tv_nsec = 0;

	while(1) {

		putchar('0');

		pthread_mutex_lock(&mutex);
		count++;
		pthread_mutex_unlock(&mutex);

		if (count == 8)
			pthread_cond_signal(&cond);


		do {
			ret = nanosleep(&req, &res);
			req.tv_sec  = res.tv_sec;
			req.tv_nsec = res.tv_nsec;
		} while (ret != 0 && errno == EINTR);


		if (ret != 0) {
			perror("nanosleep()");
			return (void *) NULL;
		}

		fflush(stdout);
	}


	return (void *) NULL;

}



void *thread2(void *dummy)
{

	while (1) {

		putchar('1');

		pthread_mutex_lock(&mutex);
		while (count != 8) {
			putchar('2');
			pthread_cond_wait(&cond, &mutex);
			putchar('3');
		}
		count = 0;
		pthread_mutex_unlock(&mutex);

		putchar('4');

	}

    return (void *) NULL;
}



int main (void)
{

    int							i, rtn;
    pthread_t					th1, th2;


	/* init mutex */
	rtn = pthread_mutex_init(&mutex, NULL);
	if (rtn != 0) {
		fprintf(stderr, "pthread_mutex_init() failed for %d.\n", rtn);
		exit(EXIT_FAILURE);
	}


	/* init cond */
	rtn = pthread_cond_init(&cond, NULL);
	if (rtn != 0) {
		fprintf(stderr, "pthread_cond_init() failed for %d.\n", rtn);
		exit(EXIT_FAILURE);
	}


	/* create threads */
	rtn = pthread_create(&th1, NULL, thread1, (void *)NULL);
	if (rtn != 0) {
		fprintf(stderr, "pthread_create() - thread#1 failed for %d.\n", rtn);
		exit(EXIT_FAILURE);
	}


	/* create threads */
	rtn = pthread_create(&th2, NULL, thread2, (void *)NULL);
	if (rtn != 0) {
		fprintf(stderr, "pthread_create() - thread#2 failed for %d.\n", rtn);
		exit(EXIT_FAILURE);
	}


	/* join */
	pthread_join(th1, NULL);
	pthread_join(th2, NULL);

	pthread_cond_destroy(&cond);
	pthread_mutex_destroy(&mutex);

    exit(EXIT_SUCCESS);

}