| /* |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| * |
| */ |
| using System; |
| using System.Threading; |
| using Apache.Qpid.Framing; |
| |
| namespace Apache.Qpid.Client.Protocol.Listener |
| { |
| public abstract class BlockingMethodFrameListener : IAMQMethodListener |
| { |
| private ManualResetEvent _resetEvent; |
| |
| public abstract bool ProcessMethod(ushort channelId, AMQMethodBody frame); |
| |
| /// <summary> |
| /// This is set if there is an exception thrown from processCommandFrame and the |
| /// exception is rethrown to the caller of blockForFrame() |
| /// </summary> |
| private volatile Exception _error; |
| |
| protected ushort _channelId; |
| |
| protected AMQMethodEvent _doneEvt = null; |
| |
| public BlockingMethodFrameListener(ushort channelId) |
| { |
| _channelId = channelId; |
| _resetEvent = new ManualResetEvent(false); |
| } |
| |
| /// <summary> |
| /// This method is called by the MINA dispatching thread. Note that it could |
| /// be called before BlockForFrame() has been called. |
| /// </summary> |
| /// <param name="evt">the frame event</param> |
| /// <returns>true if the listener has dealt with this frame</returns> |
| /// <exception cref="AMQException"></exception> |
| public bool MethodReceived(AMQMethodEvent evt) |
| { |
| AMQMethodBody method = evt.Method; |
| |
| try |
| { |
| bool ready = (evt.ChannelId == _channelId) && ProcessMethod(evt.ChannelId, method); |
| if (ready) |
| { |
| _doneEvt = evt; |
| _resetEvent.Set(); |
| } |
| |
| return ready; |
| } |
| catch (AMQException e) |
| { |
| Error(e); |
| // we rethrow the error here, and the code in the frame dispatcher will go round |
| // each listener informing them that an exception has been thrown |
| throw e; |
| } |
| } |
| |
| /// <summary> |
| /// This method is called by the thread that wants to wait for a frame. |
| /// </summary> |
| /// <param name="timeout">Set the number of milliseconds to wait</param> |
| public AMQMethodEvent BlockForFrame(int timeout) |
| { |
| _resetEvent.WaitOne(timeout, true); |
| //at this point the event will have been signalled. The error field might or might not be set |
| // depending on whether an error occurred |
| if (_error != null) |
| { |
| throw _error; |
| } |
| |
| return _doneEvt; |
| } |
| |
| /// <summary> |
| /// This is a callback, called by the MINA dispatcher thread only. It is also called from within this |
| /// class to avoid code repetition but again is only called by the MINA dispatcher thread. |
| /// </summary> |
| /// <param name="e">the exception that caused the error</param> |
| public void Error(Exception e) |
| { |
| // set the error so that the thread that is blocking (in BlockForFrame()) |
| // can pick up the exception and rethrow to the caller |
| _error = e; |
| _resetEvent.Set(); |
| } |
| } |
| } |