chan MoneyChan int;
chan AckChan bool;

class Branch
{
  static int DEPOSIT = 2;
  static int WITHDRAWL = 3;
  static int DEPOSIT_STATUS = 4;
  static int WITHDRAWL_STATUS = 5;
  
  static bool SEND = true;
  static bool RECV = false;
  
  IBank bank;
  int account;
  int funds;

  void Deposit (int amount) 
  { 
    funds = funds + amount; 
    account = account + amount; 
  }
  
  bool Withdraw (int amount) 
  {
   bool ok;
   if (amount > account) return false;
   ok = amount > funds;
   if ( ! ok) {  
     send(bank.withdrawl, amount);
     select { 
		receive(bank.withdrawlStatus, ok) -> 
			if (ok) funds = funds + amount; 
	  }
   }
   if (ok) funds = funds - amount;
   return ok;
  }

  void Run ()
  {
    int amt; int x;

	while (true) 
	{
		select end visible
		{
			event(DEPOSIT,RECV) -> { 
				Deposit(amt); 
				event(DEPOSIT_STATUS, SEND); 
			}
			event(WITHDRAWL,RECV) -> { 
				bool ok; 
				ok = Withdraw(amt); 
				event(WITHDRAWL_STATUS, SEND); 
			}
		}
    }
  }
};


class IBank
{
  MoneyChan withdrawl;
  MoneyChan deposit;
  AckChan withdrawlStatus;
  AckChan depositStatus;
  
  void Run ()
  {
    int x;
	bool b;
	
    while (true) {
      select end {
        receive(withdrawl,x) -> { 
			b = true; //choose(bool); 
			send(withdrawlStatus, b); 
		 }
        receive(deposit,x) -> {
			b = true; //choose(bool);
			send(depositStatus, b);
		 }
      }
    }
  }
};


class System
{
  static activate void Init ()
  {
    Branch br = new Branch;
    IBank b = new IBank;
    br.bank = b;
    
    b.withdrawl = new MoneyChan;
    b.deposit = new MoneyChan;
    b.withdrawlStatus = new AckChan;
    b.depositStatus = new AckChan;
    
    async br.Run();
    async b.Run();
  }
};