| /* |
| * 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.NMS.ActiveMQ.Commands; |
| |
| namespace Apache.NMS.ActiveMQ.Transport |
| { |
| /// <summary> |
| /// A Transport which guards access to the next transport using a mutex. |
| /// </summary> |
| public class MutexTransport : TransportFilter |
| { |
| private readonly object transmissionLock = new object(); |
| |
| private void GetTransmissionLock(int timeout) |
| { |
| if(timeout > 0) |
| { |
| DateTime timeoutTime = DateTime.Now + TimeSpan.FromMilliseconds(timeout); |
| int waitCount = 1; |
| |
| while(true) |
| { |
| if(Monitor.TryEnter(transmissionLock)) |
| { |
| break; |
| } |
| |
| if(DateTime.Now > timeoutTime) |
| { |
| throw new IOException(string.Format("Oneway timed out after {0} milliseconds.", timeout)); |
| } |
| |
| // Back off from being overly aggressive. Having too many threads |
| // aggressively trying to get the lock pegs the CPU. |
| Thread.Sleep(3 * (waitCount++)); |
| } |
| } |
| else |
| { |
| Monitor.Enter(transmissionLock); |
| } |
| } |
| |
| public MutexTransport(ITransport next) : base(next) |
| { |
| } |
| |
| public override void Oneway(Command command) |
| { |
| GetTransmissionLock(this.next.Timeout); |
| try |
| { |
| base.Oneway(command); |
| } |
| finally |
| { |
| Monitor.Exit(transmissionLock); |
| } |
| } |
| |
| public override FutureResponse AsyncRequest(Command command) |
| { |
| GetTransmissionLock(this.next.AsyncTimeout); |
| try |
| { |
| return base.AsyncRequest(command); |
| } |
| finally |
| { |
| Monitor.Exit(transmissionLock); |
| } |
| } |
| |
| public override Response Request(Command command, TimeSpan timeout) |
| { |
| GetTransmissionLock((int) timeout.TotalMilliseconds); |
| try |
| { |
| return base.Request(command, timeout); |
| } |
| finally |
| { |
| Monitor.Exit(transmissionLock); |
| } |
| } |
| } |
| } |