View Javadoc

1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License.
18   *
19   */
20  package org.apache.mina.transport.vmpipe;
21  
22  import java.io.IOException;
23  import java.net.SocketAddress;
24  import java.util.HashSet;
25  import java.util.Set;
26  import java.util.concurrent.Executor;
27  
28  import org.apache.mina.core.filterchain.IoFilterChain;
29  import org.apache.mina.core.future.ConnectFuture;
30  import org.apache.mina.core.future.DefaultConnectFuture;
31  import org.apache.mina.core.future.IoFuture;
32  import org.apache.mina.core.future.IoFutureListener;
33  import org.apache.mina.core.service.AbstractIoConnector;
34  import org.apache.mina.core.service.IoHandler;
35  import org.apache.mina.core.service.TransportMetadata;
36  import org.apache.mina.core.session.IdleStatusChecker;
37  import org.apache.mina.core.session.IoSessionInitializer;
38  import org.apache.mina.util.ExceptionMonitor;
39  
40  /**
41   * Connects to {@link IoHandler}s which is bound on the specified
42   * {@link VmPipeAddress}.
43   *
44   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
45   */
46  public final class VmPipeConnector extends AbstractIoConnector {
47  
48      // object used for checking session idle
49      private IdleStatusChecker idleChecker;
50      
51      /**
52       * Creates a new instance.
53       */
54      public VmPipeConnector() {
55          this(null);
56      }
57      
58      /**
59       * Creates a new instance.
60       */
61      public VmPipeConnector(Executor executor) {
62          super(new DefaultVmPipeSessionConfig(), executor);
63          idleChecker = new IdleStatusChecker();
64          // we schedule the idle status checking task in this service exceutor
65          // it will be woke up every seconds
66          executeWorker(idleChecker.getNotifyingTask(), "idleStatusChecker");
67      }
68  
69      public TransportMetadata getTransportMetadata() {
70          return VmPipeSession.METADATA;
71      }
72  
73      @Override
74      public VmPipeSessionConfig getSessionConfig() {
75          return (VmPipeSessionConfig) super.getSessionConfig();
76      }
77  
78      @Override
79      protected ConnectFuture connect0(SocketAddress remoteAddress,
80                                        SocketAddress localAddress,
81                                        IoSessionInitializer<? extends ConnectFuture> sessionInitializer) {
82          VmPipe entry = VmPipeAcceptor.boundHandlers.get(remoteAddress);
83          if (entry == null) {
84              return DefaultConnectFuture.newFailedFuture(new IOException(
85                      "Endpoint unavailable: " + remoteAddress));
86          }
87  
88          DefaultConnectFuture future = new DefaultConnectFuture();
89  
90          // Assign the local address dynamically,
91          VmPipeAddress actualLocalAddress;
92          try {
93              actualLocalAddress = nextLocalAddress();
94          } catch (IOException e) {
95              return DefaultConnectFuture.newFailedFuture(e);
96          }
97  
98          VmPipeSession localSession = new VmPipeSession(this,
99                  getListeners(), actualLocalAddress, getHandler(), entry);
100 
101         initSession(localSession, future, sessionInitializer);
102 
103         // and reclaim the local address when the connection is closed.
104         localSession.getCloseFuture().addListener(LOCAL_ADDRESS_RECLAIMER);
105 
106         // initialize connector session
107         try {
108             IoFilterChain filterChain = localSession.getFilterChain();
109             this.getFilterChainBuilder().buildFilterChain(filterChain);
110 
111             // The following sentences don't throw any exceptions.
112             getListeners().fireSessionCreated(localSession);
113             idleChecker.addSession(localSession);
114         } catch (Throwable t) {
115             future.setException(t);
116             return future;
117         }
118 
119         // initialize acceptor session
120         VmPipeSession remoteSession = localSession.getRemoteSession();
121         ((VmPipeAcceptor) remoteSession.getService()).doFinishSessionInitialization(remoteSession, null);
122         try {
123             IoFilterChain filterChain = remoteSession.getFilterChain();
124             entry.getAcceptor().getFilterChainBuilder().buildFilterChain(
125                     filterChain);
126 
127             // The following sentences don't throw any exceptions.
128             entry.getListeners().fireSessionCreated(remoteSession);
129             idleChecker.addSession(remoteSession);
130         } catch (Throwable t) {
131             ExceptionMonitor.getInstance().exceptionCaught(t);
132             remoteSession.close(true);
133         }
134 
135         // Start chains, and then allow and messages read/written to be processed. This is to ensure that
136         // sessionOpened gets received before a messageReceived
137         ((VmPipeFilterChain) localSession.getFilterChain()).start();
138         ((VmPipeFilterChain) remoteSession.getFilterChain()).start();
139 
140         return future;
141     }
142 
143     @Override
144     protected IoFuture dispose0() throws Exception {
145         // stop the idle checking task
146         idleChecker.getNotifyingTask().cancel();
147         return null;
148     }
149 
150     private static final Set<VmPipeAddress> TAKEN_LOCAL_ADDRESSES = new HashSet<VmPipeAddress>();
151 
152     private static int nextLocalPort = -1;
153 
154     private static final IoFutureListener<IoFuture> LOCAL_ADDRESS_RECLAIMER = new LocalAddressReclaimer();
155 
156     private static VmPipeAddress nextLocalAddress() throws IOException {
157         synchronized (TAKEN_LOCAL_ADDRESSES) {
158             if (nextLocalPort >= 0) {
159                 nextLocalPort = -1;
160             }
161             for (int i = 0; i < Integer.MAX_VALUE; i++) {
162                 VmPipeAddress answer = new VmPipeAddress(nextLocalPort--);
163                 if (!TAKEN_LOCAL_ADDRESSES.contains(answer)) {
164                     TAKEN_LOCAL_ADDRESSES.add(answer);
165                     return answer;
166                 }
167             }
168         }
169 
170         throw new IOException("Can't assign a local VM pipe port.");
171     }
172 
173     private static class LocalAddressReclaimer implements IoFutureListener<IoFuture> {
174         public void operationComplete(IoFuture future) {
175             synchronized (TAKEN_LOCAL_ADDRESSES) {
176                 TAKEN_LOCAL_ADDRESSES.remove(future.getSession()
177                         .getLocalAddress());
178             }
179         }
180     }
181 }