IoSender.java
001 /*
002  * Licensed to the Apache Software Foundation (ASF) under one
003  * or more contributor license agreements.  See the NOTICE file
004  * distributed with this work for additional information
005  * regarding copyright ownership.  The ASF licenses this file
006  * to you under the Apache License, Version 2.0 (the
007  * "License"); you may not use this file except in compliance
008  * with the License.  You may obtain a copy of the License at
009  *
010  *   http://www.apache.org/licenses/LICENSE-2.0
011  *
012  * Unless required by applicable law or agreed to in writing,
013  * software distributed under the License is distributed on an
014  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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016  * specific language governing permissions and limitations
017  * under the License.
018  */
019 package org.apache.qpid.transport.network.io;
020 
021 import static org.apache.qpid.transport.util.Functions.mod;
022 
023 import java.io.IOException;
024 import java.io.OutputStream;
025 import java.net.Socket;
026 import java.nio.ByteBuffer;
027 import java.util.concurrent.atomic.AtomicBoolean;
028 
029 import org.apache.qpid.thread.Threading;
030 import org.apache.qpid.transport.Sender;
031 import org.apache.qpid.transport.SenderException;
032 import org.apache.qpid.transport.TransportException;
033 import org.apache.qpid.transport.util.Logger;
034 
035 
036 public final class IoSender implements Runnable, Sender<ByteBuffer>
037 {
038 
039     private static final Logger log = Logger.get(IoSender.class);
040 
041     // by starting here, we ensure that we always test the wraparound
042     // case, we should probably make this configurable somehow so that
043     // we can test other cases as well
044     private final static int START = Integer.MAX_VALUE - 10;
045 
046     private final IoTransport transport;
047     private final long timeout;
048     private final Socket socket;
049     private final OutputStream out;
050 
051     private final byte[] buffer;
052     private volatile int head = START;
053     private volatile int tail = START;
054     private volatile boolean idle = true;
055     private final Object notFull = new Object();
056     private final Object notEmpty = new Object();
057     private final AtomicBoolean closed = new AtomicBoolean(false);
058     private final Thread senderThread;
059     private long idleTimeout;
060     
061     private volatile Throwable exception = null;
062 
063 
064     public IoSender(IoTransport transport, int bufferSize, long timeout)
065     {
066         this.transport = transport;
067         this.socket = transport.getSocket();
068         this.buffer = new byte[pof2(bufferSize)]// buffer size must be a power of 2
069         this.timeout = timeout;
070 
071         try
072         {
073             out = socket.getOutputStream();
074         }
075         catch (IOException e)
076         {
077             throw new TransportException("Error getting output stream for socket", e);
078         }
079 
080         try
081         {
082             senderThread = Threading.getThreadFactory().createThread(this);                      
083         }
084         catch(Exception e)
085         {
086             throw new Error("Error creating IOSender thread",e);
087         }
088         
089         senderThread.setDaemon(true);
090         senderThread.setName(String.format("IoSender - %s", socket.getRemoteSocketAddress()));
091         senderThread.start();
092     }
093 
094     private static final int pof2(int n)
095     {
096         int result = 1;
097         while (result < n)
098         {
099             result *= 2;
100         }
101         return result;
102     }
103 
104     public void send(ByteBuffer buf)
105     {
106         if (closed.get())
107         {
108             throw new SenderException("sender is closed", exception);
109         }
110 
111         final int size = buffer.length;
112         int remaining = buf.remaining();
113 
114         while (remaining > 0)
115         {
116             final int hd = head;
117             final int tl = tail;
118 
119             if (hd - tl >= size)
120             {
121                 flush();
122                 synchronized (notFull)
123                 {
124                     long start = System.currentTimeMillis();
125                     long elapsed = 0;
126                     while (!closed.get() && head - tail >= size && elapsed < timeout)
127                     {
128                         try
129                         {
130                             notFull.wait(timeout - elapsed);
131                         }
132                         catch (InterruptedException e)
133                         {
134                             // pass
135                         }
136                         elapsed += System.currentTimeMillis() - start;
137                     }
138 
139                     if (closed.get())
140                     {
141                         throw new SenderException("sender is closed", exception);
142                     }
143 
144                     if (head - tail >= size)
145                     {
146                         throw new SenderException(String.format("write timed out: %s, %s", head, tail));
147                     }
148                 }
149                 continue;
150             }
151 
152             final int hd_idx = mod(hd, size);
153             final int tl_idx = mod(tl, size);
154             final int length;
155 
156             if (tl_idx > hd_idx)
157             {
158                 length = Math.min(tl_idx - hd_idx, remaining);
159             }
160             else
161             {
162                 length = Math.min(size - hd_idx, remaining);
163             }
164 
165             buf.get(buffer, hd_idx, length);
166             head += length;
167             remaining -= length;
168         }
169     }
170 
171     public void flush()
172     {
173         if (idle)
174         {
175             synchronized (notEmpty)
176             {
177                 notEmpty.notify();
178             }
179         }
180     }
181 
182     public void close()
183     {
184         close(true);
185     }
186 
187     void close(boolean reportException)
188     {
189         if (!closed.getAndSet(true))
190         {
191             synchronized (notFull)
192             {
193                 notFull.notify();
194             }
195 
196             synchronized (notEmpty)
197             {
198                 notEmpty.notify();
199             }
200 
201             try
202             {
203                 if (Thread.currentThread() != senderThread)
204                 {
205                     senderThread.join(timeout);
206                     if (senderThread.isAlive())
207                     {
208                         throw new SenderException("join timed out");
209                     }
210                 }
211                 transport.getReceiver().close(false);
212             }
213             catch (InterruptedException e)
214             {
215                 throw new SenderException(e);
216             }
217 
218             if (reportException && exception != null)
219             {
220                 throw new SenderException(exception);
221             }
222         }
223     }
224 
225     public void run()
226     {
227         final int size = buffer.length;       
228         while (true)
229         {
230             final int hd = head;
231             final int tl = tail;
232 
233             if (hd == tl)
234             {
235                 if (closed.get())
236                 {
237                     break;
238                 }
239 
240                 idle = true;
241 
242                 synchronized (notEmpty)
243                 {
244                     while (head == tail && !closed.get())
245                     {
246                         try
247                         {
248                             notEmpty.wait();
249                         }
250                         catch (InterruptedException e)
251                         {
252                             // pass
253                         }
254                     }
255                 }
256 
257                 idle = false;
258 
259                 continue;
260             }
261 
262             final int hd_idx = mod(hd, size);
263             final int tl_idx = mod(tl, size);
264 
265             final int length;
266             if (tl_idx < hd_idx)
267             {
268                 length = hd_idx - tl_idx;
269             }
270             else
271             {
272                 length = size - tl_idx;
273             }
274 
275             try
276             {
277                 out.write(buffer, tl_idx, length);
278             }
279             catch (IOException e)
280             {
281                 log.error(e, "error in write thread");
282                 exception = e;
283                 close(false);
284                 break;
285             }
286             tail += length;
287             if (head - tl >= size)
288             {
289                 synchronized (notFull)
290                 {
291                     notFull.notify();
292                 }
293             }
294         }
295     }
296 
297     public void setIdleTimeout(long l)
298     {
299         try
300         {
301             socket.setSoTimeout((int)l*2);
302             idleTimeout = l;
303         }
304         catch (Exception e)
305         {
306             throw new SenderException(e);
307         }
308     }
309 }