//Analyze these implementations of the various sync primitives
//Assume a correct implementation of locks is provided for you
//Do these implementations satisfy the safety and liveness requirements?

//Condition Variables
void condition_wait(lock_t *lock, condition_t *cond){ 
	lock_release(lock); 
	enter_critical(); 
	block(&cond->wait_queue); 
	leave_critical(); 
	lock_acquire(lock); 
}

//Semaphores
void semaphore_up(semaphore_t *sem){
	enter_critical(); 
	++sem->value; 
	unblock_one(&sem->wait_queue); 
	leave_critical(); 
} 

void semaphore_down(semaphore_t *sem) { 
	enter_critical(); 
	if(sem->value <= 0){ 
		block(&sem->wait_queue); 
	} 
	--sem->value; 
	leave_critical(); 
}

//Barriers
void barrier_wait(barrier_t *bar){ 
	enter_critical(); 
	if(--bar->value > 0){
		block(&bar->wait_queue); 
		++bar->value; 
	} 
	else{ 
		unblock_all(&bar->wait_queue); 
		++bar->value; 
	} 
	leave_critical(); 
}