안녕하세요. pthread_cond_wait 에 관한 질문입니다.

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
 
void* function(void* ptr);
void P(int* semaphore);
void V(int* semaphore);
 
pthread_mutex_t mutex     = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t  condition = PTHREAD_COND_INITIALIZER;
int conditionMet = 0; 
int accnt1 	 = 0;
int accnt2 	 = 0;
 
int main(int argc, char** argv)
{
	pthread_t thread1, thread2;
	char* message1 = "Thread1";
	char* message2 = "Thread2";
	pthread_create( &thread1, NULL, function, (void*)message1 );
	pthread_create( &thread2, NULL, function, (void*)message2 );
	pthread_join(thread1, NULL);
	pthread_join(thread2, NULL);
	return 0;
}
 
void* function(void* ptr)
{
	int sum;
	int semaphore = 1;
	int counter = 0;
 
	do{
		int r = rand();
		P(&semaphore);
			int tmp1 = accnt1;
			int tmp2 = accnt2;
			accnt1 = tmp1 + r;
			accnt2 = tmp2 - r;
			sum  = accnt1 + accnt2;
		V(&semaphore);
	}while(sum == 0 && ++counter < 10000);
	printf("%s::COUNTER >> %d\n", (char*)ptr, counter);
}
void P(int* semaphore)
{
	pthread_mutex_lock(&mutex);
	*semaphore = *semaphore - 1;
	if(*semaphore < 0)
	{
		pthread_mutex_unlock(&mutex);
		if(!conditionMet) pthread_cond_wait(&condition, &mutex);
	}
	pthread_mutex_unlock(&mutex);
}
void V(int* semaphore)
{
	pthread_mutex_lock(&mutex);
	*semaphore = *semaphore + 1;
	conditionMet = 1;
	if(*semaphore <= 0)	pthread_cond_signal(&condition);
	else			pthread_mutex_unlock(&mutex);
}