#define _MULTI_THREADED
#include <pthread.h>
#include <stdio.h>
#include "check.h"

/* For safe condition variable usage, must use a boolean predicate and  */
/* a mutex with the condition.                                          */
int                 conditionMet = 0;
pthread_cond_t      cond  = PTHREAD_COND_INITIALIZER;
pthread_mutex_t     mutex = PTHREAD_MUTEX_INITIALIZER;

#define NTHREADS    5

void *threadfunc(void *parm)
{
	int           rc;

	rc = pthread_mutex_lock(&mutex);
	checkResults("pthread_mutex_lock()\n", rc);

	while (!conditionMet) {
		printf("Thread blocked\n");
		rc = pthread_cond_wait(&cond, &mutex);
		checkResults("pthread_cond_wait()\n", rc);
	}

	rc = pthread_mutex_unlock(&mutex);
	checkResults("pthread_mutex_lock()\n", rc);
	return NULL;
}

int main(int argc, char **argv)
{
	int                   rc=0;
	int                   i;
	pthread_t             threadid[NTHREADS];

	printf("Enter Testcase - %s\n", argv[0]);

	printf("Create %d threads\n", NTHREADS);
	for(i=0; i<NTHREADS; ++i) {
		rc = pthread_create(&threadid[i], NULL, threadfunc, NULL);
		checkResults("pthread_create()\n", rc);
	}

	sleep(5);  /* Sleep is not a very robust way to serialize threads */
	rc = pthread_mutex_lock(&mutex);
	checkResults("pthread_mutex_lock()\n", rc);

	/* The condition has occured. Set the flag and wake up any waiting threads */
	conditionMet = 1;
	printf("Wake up all waiting threads...\n");
	rc = pthread_cond_broadcast(&cond);
	checkResults("pthread_cond_broadcast()\n", rc);

	rc = pthread_mutex_unlock(&mutex);
	checkResults("pthread_mutex_unlock()\n", rc);

	printf("Wait for threads and cleanup\n");
	for (i=0; i<NTHREADS; ++i) {
		rc = pthread_join(threadid[i], NULL);
		checkResults("pthread_join()\n", rc);
	}
	pthread_cond_destroy(&cond);
	pthread_mutex_destroy(&mutex);

	printf("Main completed\n");
	return 0;
}