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1   /*
2    * ====================================================================
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *   http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing,
14   * software distributed under the License is distributed on an
15   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16   * KIND, either express or implied.  See the License for the
17   * specific language governing permissions and limitations
18   * under the License.
19   * ====================================================================
20   *
21   * This software consists of voluntary contributions made by many
22   * individuals on behalf of the Apache Software Foundation.  For more
23   * information on the Apache Software Foundation, please see
24   * <http://www.apache.org/>.
25   *
26   */
27  
28  package org.apache.hc.core5.reactor;
29  
30  import java.io.IOException;
31  import java.net.BindException;
32  import java.net.ServerSocket;
33  import java.net.SocketAddress;
34  import java.nio.channels.CancelledKeyException;
35  import java.nio.channels.SelectionKey;
36  import java.nio.channels.ServerSocketChannel;
37  import java.nio.channels.SocketChannel;
38  import java.util.HashSet;
39  import java.util.Iterator;
40  import java.util.Queue;
41  import java.util.Set;
42  import java.util.concurrent.ConcurrentHashMap;
43  import java.util.concurrent.ConcurrentLinkedQueue;
44  import java.util.concurrent.ConcurrentMap;
45  import java.util.concurrent.Future;
46  import java.util.concurrent.atomic.AtomicBoolean;
47  
48  import org.apache.hc.core5.concurrent.BasicFuture;
49  import org.apache.hc.core5.concurrent.FutureCallback;
50  import org.apache.hc.core5.function.Callback;
51  import org.apache.hc.core5.io.Closer;
52  
53  class SingleCoreListeningIOReactor extends AbstractSingleCoreIOReactor implements ConnectionAcceptor {
54  
55      private final IOReactorConfig reactorConfig;
56      private final Callback<SocketChannel> callback;
57      private final Queue<ListenerEndpointRequest> requestQueue;
58      private final ConcurrentMap<ListenerEndpoint, Boolean> endpoints;
59      private final AtomicBoolean paused;
60      private final long selectTimeoutMillis;
61  
62      SingleCoreListeningIOReactor(
63              final Callback<Exception> exceptionCallback,
64              final IOReactorConfig ioReactorConfig,
65              final Callback<SocketChannel> callback) {
66          super(exceptionCallback);
67          this.reactorConfig = ioReactorConfig != null ? ioReactorConfig : IOReactorConfig.DEFAULT;
68          this.callback = callback;
69          this.requestQueue = new ConcurrentLinkedQueue<>();
70          this.endpoints = new ConcurrentHashMap<>();
71          this.paused = new AtomicBoolean(false);
72          this.selectTimeoutMillis = this.reactorConfig.getSelectInterval().toMillis();
73      }
74  
75      @Override
76      void doTerminate() {
77          ListenerEndpointRequest request;
78          while ((request = this.requestQueue.poll()) != null) {
79              request.cancel();
80          }
81      }
82  
83      @Override
84      protected final void doExecute() throws IOException {
85          while (!Thread.currentThread().isInterrupted()) {
86              if (getStatus().compareTo(IOReactorStatus.ACTIVE) != 0) {
87                  break;
88              }
89  
90              final int readyCount = this.selector.select(this.selectTimeoutMillis);
91  
92              if (getStatus().compareTo(IOReactorStatus.ACTIVE) != 0) {
93                  break;
94              }
95  
96              processEvents(readyCount);
97          }
98      }
99  
100     private void processEvents(final int readyCount) throws IOException {
101         if (!this.paused.get()) {
102             processSessionRequests();
103         }
104 
105         if (readyCount > 0) {
106             final Set<SelectionKey> selectedKeys = this.selector.selectedKeys();
107             for (final SelectionKey key : selectedKeys) {
108 
109                 processEvent(key);
110 
111             }
112             selectedKeys.clear();
113         }
114     }
115 
116     private void processEvent(final SelectionKey key) throws IOException {
117         try {
118 
119             if (key.isAcceptable()) {
120 
121                 final ServerSocketChannel serverChannel = (ServerSocketChannel) key.channel();
122                 for (;;) {
123                     final SocketChannel socketChannel = serverChannel.accept();
124                     if (socketChannel == null) {
125                         break;
126                     }
127                     this.callback.execute(socketChannel);
128                 }
129             }
130 
131         } catch (final CancelledKeyException ex) {
132             final ListenerEndpoint../org/apache/hc/core5/reactor/ListenerEndpoint.html#ListenerEndpoint">ListenerEndpoint endpoint = (ListenerEndpoint) key.attachment();
133             this.endpoints.remove(endpoint);
134             key.attach(null);
135         }
136     }
137 
138     @Override
139     public Future<ListenerEndpoint> listen(final SocketAddress address, final FutureCallback<ListenerEndpoint> callback) {
140         if (getStatus().compareTo(IOReactorStatus.SHUTTING_DOWN) >= 0) {
141             throw new IOReactorShutdownException("I/O reactor has been shut down");
142         }
143         final BasicFuture<ListenerEndpoint> future = new BasicFuture<>(callback);
144         this.requestQueue.add(new ListenerEndpointRequest(address, future));
145         this.selector.wakeup();
146         return future;
147     }
148 
149     private void processSessionRequests() throws IOException {
150         ListenerEndpointRequest request;
151         while ((request = this.requestQueue.poll()) != null) {
152             if (request.isCancelled()) {
153                 continue;
154             }
155             final SocketAddress address = request.address;
156             final ServerSocketChannel serverChannel = ServerSocketChannel.open();
157             try {
158                 final ServerSocket socket = serverChannel.socket();
159                 socket.setReuseAddress(this.reactorConfig.isSoReuseAddress());
160                 if (this.reactorConfig.getRcvBufSize() > 0) {
161                     socket.setReceiveBufferSize(this.reactorConfig.getRcvBufSize());
162                 }
163                 serverChannel.configureBlocking(false);
164 
165                 try {
166                     socket.bind(address, this.reactorConfig.getBacklogSize());
167                 } catch (final BindException ex) {
168                     final BindException detailedEx = new BindException(
169                             String.format("Socket bind failure for socket %s, address=%s, BacklogSize=%,d: %s", socket,
170                                     address, this.reactorConfig.getBacklogSize(), ex));
171                     detailedEx.setStackTrace(ex.getStackTrace());
172                     throw detailedEx;
173                 }
174 
175                 final SelectionKey key = serverChannel.register(this.selector, SelectionKey.OP_ACCEPT);
176                 key.attach(request);
177                 final ListenerEndpoint endpoint = new ListenerEndpointImpl(key, socket.getLocalSocketAddress());
178                 this.endpoints.put(endpoint, Boolean.TRUE);
179                 request.completed(endpoint);
180             } catch (final IOException ex) {
181                 Closer.closeQuietly(serverChannel);
182                 request.failed(ex);
183             }
184         }
185     }
186 
187     @Override
188     public Set<ListenerEndpoint> getEndpoints() {
189         final Set<ListenerEndpoint> set = new HashSet<>();
190         final Iterator<ListenerEndpoint> it = this.endpoints.keySet().iterator();
191         while (it.hasNext()) {
192             final ListenerEndpoint endpoint = it.next();
193             if (!endpoint.isClosed()) {
194                 set.add(endpoint);
195             } else {
196                 it.remove();
197             }
198         }
199         return set;
200     }
201 
202     @Override
203     public void pause() throws IOException {
204         if (paused.compareAndSet(false, true)) {
205             final Iterator<ListenerEndpoint> it = this.endpoints.keySet().iterator();
206             while (it.hasNext()) {
207                 final ListenerEndpoint endpoint = it.next();
208                 if (!endpoint.isClosed()) {
209                     endpoint.close();
210                     this.requestQueue.add(new ListenerEndpointRequest(endpoint.getAddress(), null));
211                 }
212                 it.remove();
213             }
214         }
215     }
216 
217     @Override
218     public void resume() throws IOException {
219         if (paused.compareAndSet(true, false)) {
220             this.selector.wakeup();
221         }
222     }
223 
224 }