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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, SocketAddress localAddress,
80              IoSessionInitializer<? extends ConnectFuture> sessionInitializer) {
81          VmPipe entry = VmPipeAcceptor.boundHandlers.get(remoteAddress);
82          if (entry == null) {
83              return DefaultConnectFuture.newFailedFuture(new IOException("Endpoint unavailable: " + remoteAddress));
84          }
85  
86          DefaultConnectFuture future = new DefaultConnectFuture();
87  
88          // Assign the local address dynamically,
89          VmPipeAddress actualLocalAddress;
90          try {
91              actualLocalAddress = nextLocalAddress();
92          } catch (IOException e) {
93              return DefaultConnectFuture.newFailedFuture(e);
94          }
95  
96          VmPipeSession localSession = new VmPipeSession(this, getListeners(), actualLocalAddress, getHandler(), entry);
97  
98          initSession(localSession, future, sessionInitializer);
99  
100         // and reclaim the local address when the connection is closed.
101         localSession.getCloseFuture().addListener(LOCAL_ADDRESS_RECLAIMER);
102 
103         // initialize connector session
104         try {
105             IoFilterChain filterChain = localSession.getFilterChain();
106             this.getFilterChainBuilder().buildFilterChain(filterChain);
107 
108             // The following sentences don't throw any exceptions.
109             getListeners().fireSessionCreated(localSession);
110             idleChecker.addSession(localSession);
111         } catch (Throwable t) {
112             future.setException(t);
113             return future;
114         }
115 
116         // initialize acceptor session
117         VmPipeSession remoteSession = localSession.getRemoteSession();
118         ((VmPipeAcceptor) remoteSession.getService()).doFinishSessionInitialization(remoteSession, null);
119         try {
120             IoFilterChain filterChain = remoteSession.getFilterChain();
121             entry.getAcceptor().getFilterChainBuilder().buildFilterChain(filterChain);
122 
123             // The following sentences don't throw any exceptions.
124             entry.getListeners().fireSessionCreated(remoteSession);
125             idleChecker.addSession(remoteSession);
126         } catch (Throwable t) {
127             ExceptionMonitor.getInstance().exceptionCaught(t);
128             remoteSession.close(true);
129         }
130 
131         // Start chains, and then allow and messages read/written to be processed. This is to ensure that
132         // sessionOpened gets received before a messageReceived
133         ((VmPipeFilterChain) localSession.getFilterChain()).start();
134         ((VmPipeFilterChain) remoteSession.getFilterChain()).start();
135 
136         return future;
137     }
138 
139     @Override
140     protected void dispose0() throws Exception {
141         // stop the idle checking task
142         idleChecker.getNotifyingTask().cancel();
143     }
144 
145     private static final Set<VmPipeAddress> TAKEN_LOCAL_ADDRESSES = new HashSet<VmPipeAddress>();
146 
147     private static int nextLocalPort = -1;
148 
149     private static final IoFutureListener<IoFuture> LOCAL_ADDRESS_RECLAIMER = new LocalAddressReclaimer();
150 
151     private static VmPipeAddress nextLocalAddress() throws IOException {
152         synchronized (TAKEN_LOCAL_ADDRESSES) {
153             if (nextLocalPort >= 0) {
154                 nextLocalPort = -1;
155             }
156             for (int i = 0; i < Integer.MAX_VALUE; i++) {
157                 VmPipeAddress answer = new VmPipeAddress(nextLocalPort--);
158                 if (!TAKEN_LOCAL_ADDRESSES.contains(answer)) {
159                     TAKEN_LOCAL_ADDRESSES.add(answer);
160                     return answer;
161                 }
162             }
163         }
164 
165         throw new IOException("Can't assign a local VM pipe port.");
166     }
167 
168     private static class LocalAddressReclaimer implements IoFutureListener<IoFuture> {
169         public void operationComplete(IoFuture future) {
170             synchronized (TAKEN_LOCAL_ADDRESSES) {
171                 TAKEN_LOCAL_ADDRESSES.remove(future.getSession().getLocalAddress());
172             }
173         }
174     }
175 }