#include <countsem.h>

CountingSemaphore::CountingSemaphore(int ini_value = 0)
{
  count = ini_value;
  pthread_cond_init(&c, NULL);
  pthread_mutex_init(&c_m, NULL);
  pthread_mutex_init(&m, NULL);
}

CountingSemaphore::~CountingSemaphore( ) {
  pthread_cond_destroy(&c);
  pthread_mutex_destroy(&c_m);
  pthread_mutex_destroy(&m);
}


void CountingSemaphore::P(void)
{
	while(1) {
		pthread_mutex_lock(&m);
		if(count > 0) {
			count--;
			pthread_mutex_unlock(&m);
			return;
		}
		pthread_mutex_unlock(&m);
		pthread_mutex_lock(&c_m);
		pthread_cond_wait(&c, &c_m);
		pthread_mutex_unlock(&c_m);
  }
}    


void CountingSemaphore::V(void)
{
	pthread_mutex_lock(&m);
	count ++;
	pthread_mutex_unlock(&m);
	pthread_cond_signal(&c);
}

void CountingSemaphore::SetVal(int num)
{
	pthread_mutex_lock(&m);
	count = num;
	if(num > 0) pthread_cond_signal(&c);
	pthread_mutex_unlock(&m);

}