/**
 *   This class encapsulates condition variables functionality
 *
 *  Autor: Sistemas Operativos (Francisco Arroyo)
 *
 *  Fecha: 2023/Abr/23
 *
 **/

#include "Condition.h"

/**
 *  Creates a new condition variable
 *
 *  Uses an internal structure to make workers wait for resources
 *
 **/
Condition::Condition() {

   this->waitingWorkers = 0;
   this->internalWaitMechanism = new Lock();

}


/**
 *   Destroys our condition variable
 **/
Condition::~Condition() {
   delete this->internalWaitMechanism;
}


/**
 *  Wait for the condition controlled by our variable
 *
**/
void Condition::Wait( Lock & affectedLock ) {

   this->waitingWorkers++;
   affectedLock.Release();
   this->internalWaitMechanism->Acquire();
   affectedLock.Acquire();

} 

  
/**
 *  Notify one worker from the queue, if empty has no effect
 *
 **/
void Condition::NotifyOne() {

   if ( this->waitingWorkers > 0 ) {
      this->waitingWorkers--;	// One
      this->internalWaitMechanism->Release();
   }

}


/**
 *  Same method as notify one, declared for compatibility with many examples
 *
**/
void Condition::Signal() {

   this->NotifyOne();

}


/**
 *  Signal all workers from the queue, if empty has no effect
 *
**/
void Condition::NotifyAll() {

   while ( this->waitingWorkers > 0 ) {
      this->waitingWorkers--;
      this->internalWaitMechanism->Release();
   }

}