조건변수에서 뮤텍스 사용하기

int main(){
....
	state = pthread_mutex_init(&mutx, NULL);
	pthread_cond_init(&sync_cond, NULL);		//initialize condition variable 
 
	if(state != 0){
		puts("Failure initializing semaphore\n");
		exit(1);
	}
        ......
	pthread_cond_destroy(&sync_cond);	//condition variable destroy
	pthread_mutex_destroy(&mutx);		//mutex destroy
	return 0;
}

void *thread_HNV(CARS arg)	
{
	printf("Car to SEOUL is approaching... \n");
	pthread_mutex_lock(&mutx);			//locking mutex
	if (On_Bridge == 0){				// IF there is no car on the bridge..
		On_Bridge= TO_SEOUL;				//Change Bridge status.
		n_Cars_H++;					//increase passed cars.
		CARS* temp= dequeue_H(&arg);			//deque it 
		printf("Cars on the Bridge...: %d\n", On_Bridge);
	}
	else if (On_Bridge != 0){			//If there is some other cars on the bridge...
		pthread_cond_signal(&sync_cond);
 
	}
	//pthread_cond_signal(&sync_cond);
	//pthread_mutex_unlock(&mutex);
	sleep(1);
 
	pthread_mutex_unlock(&mutx);
 
}
 
void *thread_NWC(CARS arg)	//cars to
{
	printf("Car to BUSAN is approaching... \n");
	pthread_mutex_lock(&mutx);			//locking mutex
	if (On_Bridge == 0 ){				// IF there is no car on the bridge..
		On_Bridge= TO_BUSAN;				//Change Bridge status.
		n_Cars++;					//increase passed cars.
		CARS* temp= dequeue(&arg);			//deque it 
		printf("Cars on the Bridge...: %d\n", On_Bridge);
	}
	else if (On_Bridge != 0){			//If there is some other cars on the bridge...
		pthread_cond_signal(&sync_cond);	//Pass the priority to other thread ...
 
	}
	sleep(1);
	pthread_mutex_unlock(&mutx);
 
 
}