[HAMA-972] Synchronization on local variable

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Not A Problem
• Component/s: bsp core
• Assignee: Unassigned
• Reporter: JongYoon Lim
• Created: 02/Sep/15 09:36
• Updated: 03/Sep/15 08:50
• Resolved: 03/Sep/15 08:50

Description

I'm not sure that the synchronization of the following code is proper.
In the code, it uses the call variable as a lock. But it's a local variable. So whenever this function is called, the lock is changed. I think this is a bug... What do you think..? Is there anything that I'm missing..?

// Client.java 
public Writable call(Writable param, ConnectionId remoteId)
      throws InterruptedException, IOException {
    Call call = new Call(param);

    Connection connection = getConnection(remoteId, call);

    connection.sendParam(call); // send the parameter
    boolean interrupted = false;

    synchronized (call) {
      int callFailCount = 0;
      while (!call.done) {
        try {
          call.wait(1000); // wait for the result
          // prevent client hang from response error
          if (callFailCount++ == IPC_CLIENT_CONNECT_MAX_RETRIES_DEFAULT)
            break;
        } catch (InterruptedException ie) {
          interrupted = true;
        }
      }

      if (interrupted) {
        // set the interrupt flag now that we are done waiting
        Thread.currentThread().interrupt();

      }

      if (call.error != null) {
        if (call.error instanceof RemoteException) {
          call.error.fillInStackTrace();
          throw call.error;
        } else { // local exception
          // use the connection because it will reflect an ip change,
          // unlike
          // the remoteId
          throw wrapException(connection.getRemoteAddress(), call.error);
        }
      } else {
        return call.value;
      }
    }
  }