#include "synch.h"
#include "system.h"
#include "mailbox.h"

//Mailbox::Mailbox(){
//}

Mailbox::Mailbox(char* debugName = "mail"){
  DEBUG('l', "Entering Constructor\n");
  m_boxLock = new Lock(debugName);
  m_waitForReceiver = new Condition(debugName);
  m_okToWrite = new Condition(debugName);
  m_okToRead = new Condition(debugName);
  m_messagePosted = new Condition(debugName);
  m_messageReceived = new Condition(debugName);
  m_newMessage = 0;
  m_AS = 0;
  m_AR = 0;
  DEBUG('l', "Exiting constructor\n");
}

Mailbox::~Mailbox(){

}

void Mailbox::Send(int message){
  DEBUG('l', "%s Entering Send\n", currentThread->getName());
  m_boxLock->Acquire();
  while(m_AS > 0){
    DEBUG('l', "%s waiting for okToWrite\n", currentThread->getName());
    m_okToWrite->Wait(m_boxLock);
  }
  m_AS++;
  while(m_AR==0){
    DEBUG('l', "%s Waiting For Receiver\n", currentThread->getName());
    m_waitForReceiver->Wait(m_boxLock);
  }
  
  DEBUG('l', "%s Writing Message\n", currentThread->getName());
  
  m_receiveBuffer = message;
  m_newMessage = 1;

  DEBUG('l', "%s Signalling new Message\n", currentThread->getName());
  m_messagePosted->Signal(m_boxLock);
  while(m_newMessage==1){
    DEBUG('l', "%s waiting for reception\n", currentThread->getName());
    m_messageReceived->Wait(m_boxLock);
  }
  m_AS--;
  DEBUG('l', "%s Signalling ok to write\n", currentThread->getName());
  m_okToWrite->Signal(m_boxLock);
  DEBUG('l', "%s releasing lock\n", currentThread->getName());
  m_boxLock->Release();
  
}





void Mailbox::Receive(int* message){
  DEBUG('l', "%s Entering Receive\n", currentThread->getName());
  DEBUG('l', "%s Aquiring Lock\n", currentThread->getName());
  m_boxLock->Acquire();
  while(m_AR > 0){
    DEBUG('l', "%s waiting for ok to read\n", currentThread->getName());
    m_okToRead->Wait(m_boxLock);
  }
  
  m_AR++;
  DEBUG('l', "%s Signalling that a receiver is present\n", currentThread->getName());
  m_waitForReceiver->Signal(m_boxLock);

  while(m_newMessage==0){
    DEBUG('l', "%s waiting for new message\n", currentThread->getName());
    m_messagePosted->Wait(m_boxLock);
  }

  DEBUG('l', "%s Copying message\n", currentThread->getName());
  
  *message = m_receiveBuffer;
  m_newMessage = 0;

  DEBUG('l', "%s Signalling message reception\n", currentThread->getName());
  
  m_messageReceived->Signal(m_boxLock);
  m_AR--;
  DEBUG('l', "%s Signalling ok to read\n", currentThread->getName());
  m_okToRead->Signal(m_boxLock);
  DEBUG('l', "%s releasing lock\n", currentThread->getName());
  m_boxLock->Release();
}