Resolved issue: NETTY-140 ChannelFuture.await*() should throw an IllegalStateException if dead lock is expected

* Added IoWorkerRunnable which maintains a thread local boolean variable
* Improved DefaultChannelFuture to check IoWorkerRunnable.IN_IO_THREAD to detect possible dead lock
* All I/O worker runnables are wrapped by IoWorkerRunnable.

src/main/java/org/jboss/netty/channel/DefaultChannelFuture.java

@@ -30,6 +30,7 @@ import java.util.concurrent.TimeUnit;
 
 import org.jboss.netty.logging.InternalLogger;
 import org.jboss.netty.logging.InternalLoggerFactory;
+import org.jboss.netty.util.internal.IoWorkerRunnable;
 
 /**
  * The default {@link ChannelFuture} implementation.  It is recommended to
@@ -144,6 +145,7 @@ public class DefaultChannelFuture implements ChannelFuture {
     public ChannelFuture await() throws InterruptedException {
         synchronized (this) {
             while (!done) {
+                checkDeadLock();
                 waiters++;
                 try {
                     this.wait();
@@ -167,6 +169,7 @@ public class DefaultChannelFuture implements ChannelFuture {
     public ChannelFuture awaitUninterruptibly() {
         synchronized (this) {
             while (!done) {
+                checkDeadLock();
                 waiters++;
                 try {
                     this.wait();
@@ -208,6 +211,7 @@ public class DefaultChannelFuture implements ChannelFuture {
                 return done;
             }
 
+            checkDeadLock();
             waiters++;
             try {
                 for (;;) {
@@ -234,6 +238,14 @@ public class DefaultChannelFuture implements ChannelFuture {
         }
     }
 
+    private void checkDeadLock() {
+        if (IoWorkerRunnable.IN_IO_THREAD.get()) {
+            throw new IllegalStateException(
+                    "await*() in I/O thread causes a dead lock or " +
+                    "sudden performance drop.");
+        }
+    }
+
     public boolean setSuccess() {
         synchronized (this) {
             // Allow only once.

src/main/java/org/jboss/netty/channel/socket/http/HttpTunnelingClientSocketPipelineSink.java

@@ -35,6 +35,7 @@ import org.jboss.netty.channel.ChannelPipeline;
 import org.jboss.netty.channel.ChannelState;
 import org.jboss.netty.channel.ChannelStateEvent;
 import org.jboss.netty.channel.MessageEvent;
+import org.jboss.netty.util.internal.IoWorkerRunnable;
 import org.jboss.netty.util.internal.ThreadRenamingRunnable;
 
 /**
@@ -123,12 +124,14 @@ final class HttpTunnelingClientSocketPipelineSink extends AbstractChannelSink {
             fireChannelConnected(channel, channel.getRemoteAddress());
 
             // Start the business.
-            workerExecutor.execute(new ThreadRenamingRunnable(
+            workerExecutor.execute(
-                    new HttpTunnelWorker(channel),
+                    new IoWorkerRunnable(
-                    "Old I/O client worker (channelId: " + channel.getId() + ", " +
+                            new ThreadRenamingRunnable(
-                    channel.getLocalAddress() + " => " +
+                                    new HttpTunnelWorker(channel),
-                    channel.getRemoteAddress() + ')'));
+                                    "Old I/O client worker (channelId: " +
-
+                                    channel.getId() + ", " +
+                                    channel.getLocalAddress() + " => " +
+                                    channel.getRemoteAddress() + ')')));
             workerStarted = true;
         } catch (Throwable t) {
             future.setFailure(t);

src/main/java/org/jboss/netty/channel/socket/nio/NioClientSocketPipelineSink.java

@@ -48,6 +48,7 @@ import org.jboss.netty.channel.ChannelStateEvent;
 import org.jboss.netty.channel.MessageEvent;
 import org.jboss.netty.logging.InternalLogger;
 import org.jboss.netty.logging.InternalLoggerFactory;
+import org.jboss.netty.util.internal.IoWorkerRunnable;
 import org.jboss.netty.util.internal.LinkedTransferQueue;
 import org.jboss.netty.util.internal.ThreadRenamingRunnable;
 
@@ -189,8 +190,10 @@ class NioClientSocketPipelineSink extends AbstractChannelSink {
                     // Start the worker thread with the new Selector.
                     boolean success = false;
                     try {
-                        bossExecutor.execute(new ThreadRenamingRunnable(
+                        bossExecutor.execute(
-                                this, "New I/O client boss #" + id));
+                                new IoWorkerRunnable(
+                                        new ThreadRenamingRunnable(
+                                                this, "New I/O client boss #" + id)));
                         success = true;
                     } finally {
                         if (!success) {

src/main/java/org/jboss/netty/channel/socket/nio/NioServerSocketPipelineSink.java

@@ -42,6 +42,7 @@ import org.jboss.netty.channel.ChannelStateEvent;
 import org.jboss.netty.channel.MessageEvent;
 import org.jboss.netty.logging.InternalLogger;
 import org.jboss.netty.logging.InternalLoggerFactory;
+import org.jboss.netty.util.internal.IoWorkerRunnable;
 import org.jboss.netty.util.internal.ThreadRenamingRunnable;
 
 /**
@@ -155,10 +156,13 @@ class NioServerSocketPipelineSink extends AbstractChannelSink {
 
             Executor bossExecutor =
                 ((NioServerSocketChannelFactory) channel.getFactory()).bossExecutor;
-            bossExecutor.execute(new ThreadRenamingRunnable(
+            bossExecutor.execute(
-                    new Boss(channel),
+                    new IoWorkerRunnable(
-                    "New I/O server boss #" + id +" (channelId: " + channel.getId() +
+                            new ThreadRenamingRunnable(
-                    ", " + channel.getLocalAddress() + ')'));
+                                    new Boss(channel),
+                                    "New I/O server boss #" + id +
+                                    " (channelId: " + channel.getId() +
+                                    ", " + channel.getLocalAddress() + ')')));
             bossStarted = true;
         } catch (Throwable t) {
             future.setFailure(t);

src/main/java/org/jboss/netty/channel/socket/nio/NioWorker.java

@@ -51,6 +51,7 @@ import org.jboss.netty.channel.MessageEvent;
 import org.jboss.netty.channel.ReceiveBufferSizePredictor;
 import org.jboss.netty.logging.InternalLogger;
 import org.jboss.netty.logging.InternalLoggerFactory;
+import org.jboss.netty.util.internal.IoWorkerRunnable;
 import org.jboss.netty.util.internal.LinkedTransferQueue;
 import org.jboss.netty.util.internal.ThreadRenamingRunnable;
 
@@ -110,7 +111,9 @@ class NioWorker implements Runnable {
 
                 boolean success = false;
                 try {
-                    executor.execute(new ThreadRenamingRunnable(this, threadName));
+                    executor.execute(
+                            new IoWorkerRunnable(
+                                    new ThreadRenamingRunnable(this, threadName)));
                     success = true;
                 } finally {
                     if (!success) {

src/main/java/org/jboss/netty/channel/socket/oio/OioClientSocketPipelineSink.java

@@ -36,6 +36,7 @@ import org.jboss.netty.channel.ChannelPipeline;
 import org.jboss.netty.channel.ChannelState;
 import org.jboss.netty.channel.ChannelStateEvent;
 import org.jboss.netty.channel.MessageEvent;
+import org.jboss.netty.util.internal.IoWorkerRunnable;
 import org.jboss.netty.util.internal.ThreadRenamingRunnable;
 
 /**
@@ -133,12 +134,14 @@ class OioClientSocketPipelineSink extends AbstractChannelSink {
             fireChannelConnected(channel, channel.getRemoteAddress());
 
             // Start the business.
-            workerExecutor.execute(new ThreadRenamingRunnable(
+            workerExecutor.execute(
-                    new OioWorker(channel),
+                    new IoWorkerRunnable(
-                    "Old I/O client worker (channelId: " + channel.getId() + ", " +
+                            new ThreadRenamingRunnable(
-                    channel.getLocalAddress() + " => " +
+                                    new OioWorker(channel),
-                    channel.getRemoteAddress() + ')'));
+                                    "Old I/O client worker (channelId: " +
-
+                                    channel.getId() + ", " +
+                                    channel.getLocalAddress() + " => " +
+                                    channel.getRemoteAddress() + ')')));
             workerStarted = true;
         } catch (Throwable t) {
             future.setFailure(t);

src/main/java/org/jboss/netty/channel/socket/oio/OioDatagramPipelineSink.java

@@ -35,6 +35,7 @@ import org.jboss.netty.channel.ChannelPipeline;
 import org.jboss.netty.channel.ChannelState;
 import org.jboss.netty.channel.ChannelStateEvent;
 import org.jboss.netty.channel.MessageEvent;
+import org.jboss.netty.util.internal.IoWorkerRunnable;
 import org.jboss.netty.util.internal.ThreadRenamingRunnable;
 
 /**
@@ -106,11 +107,13 @@ class OioDatagramPipelineSink extends AbstractChannelSink {
             fireChannelBound(channel, channel.getLocalAddress());
 
             // Start the business.
-            workerExecutor.execute(new ThreadRenamingRunnable(
+            workerExecutor.execute(
-                    new OioDatagramWorker(channel),
+                    new IoWorkerRunnable(
-                    "Old I/O datagram worker (channelId: " + channel.getId() + ", " +
+                            new ThreadRenamingRunnable(
-                    channel.getLocalAddress() + ')'));
+                                    new OioDatagramWorker(channel),
-
+                                    "Old I/O datagram worker (channelId: " +
+                                    channel.getId() + ", " +
+                                    channel.getLocalAddress() + ')')));
             workerStarted = true;
         } catch (Throwable t) {
             future.setFailure(t);
@@ -149,8 +152,10 @@ class OioDatagramPipelineSink extends AbstractChannelSink {
                 channel.getRemoteAddress() + ')';
             if (!bound) {
                 // Start the business.
-                workerExecutor.execute(new ThreadRenamingRunnable(
+                workerExecutor.execute(
-                        new OioDatagramWorker(channel), threadName));
+                        new IoWorkerRunnable(
+                                new ThreadRenamingRunnable(
+                                        new OioDatagramWorker(channel), threadName)));
             } else {
                 // Worker started by bind() - just rename.
                 Thread workerThread = channel.workerThread;

src/main/java/org/jboss/netty/channel/socket/oio/OioServerSocketPipelineSink.java

@@ -40,6 +40,7 @@ import org.jboss.netty.channel.ChannelStateEvent;
 import org.jboss.netty.channel.MessageEvent;
 import org.jboss.netty.logging.InternalLogger;
 import org.jboss.netty.logging.InternalLoggerFactory;
+import org.jboss.netty.util.internal.IoWorkerRunnable;
 import org.jboss.netty.util.internal.ThreadRenamingRunnable;
 
 /**
@@ -149,10 +150,12 @@ class OioServerSocketPipelineSink extends AbstractChannelSink {
 
             Executor bossExecutor =
                 ((OioServerSocketChannelFactory) channel.getFactory()).bossExecutor;
-            bossExecutor.execute(new ThreadRenamingRunnable(
+            bossExecutor.execute(
-                    new Boss(channel),
+                    new IoWorkerRunnable(
-                    "Old I/O server boss (channelId: " + channel.getId() +
+                            new ThreadRenamingRunnable(
-                    ", " + localAddress + ')'));
+                                    new Boss(channel),
+                                    "Old I/O server boss (channelId: " +
+                                    channel.getId() + ", " + localAddress + ')')));
             bossStarted = true;
         } catch (Throwable t) {
             future.setFailure(t);
@@ -203,13 +206,14 @@ class OioServerSocketPipelineSink extends AbstractChannelSink {
                                     OioServerSocketPipelineSink.this,
                                     acceptedSocket);
                         workerExecutor.execute(
-                                new ThreadRenamingRunnable(
+                                new IoWorkerRunnable(
-                                        new OioWorker(acceptedChannel),
+                                        new ThreadRenamingRunnable(
-                                        "Old I/O server worker (parentId: " +
+                                                new OioWorker(acceptedChannel),
-                                        channel.getId() +
+                                                "Old I/O server worker (parentId: " +
-                                        ", channelId: " + acceptedChannel.getId() + ", " +
+                                                channel.getId() + ", channelId: " +
-                                        channel.getRemoteAddress() + " => " +
+                                                acceptedChannel.getId() + ", " +
-                                        channel.getLocalAddress() + ')'));
+                                                channel.getRemoteAddress() + " => " +
+                                                channel.getLocalAddress() + ')')));
                     } catch (Exception e) {
                         logger.warn(
                                 "Failed to initialize an accepted socket.", e);

src/main/java/org/jboss/netty/util/internal/IoWorkerRunnable.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2009  Trustin Heuiseung Lee
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this software; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
+ */
+package org.jboss.netty.util.internal;
+
+import org.jboss.netty.channel.ChannelFuture;
+
+/**
+ * @author Trustin Heui-seung Lee (trustin@gmail.com)
+ * @version $Rev$, $Date$
+ */
+public class IoWorkerRunnable implements Runnable {
+
+    /**
+     * An <em>internal use only</em> thread-local variable that determines if
+     * the caller is running on an I/O worker thread, which is the case where
+     * the caller enters a dead lock if the caller calls
+     * {@link ChannelFuture#await()} or {@link ChannelFuture#awaitUninterruptibly()}.
+     */
+    public static final ThreadLocal<Boolean> IN_IO_THREAD = new ThreadLocalBoolean();
+
+    private final Runnable runnable;
+
+    public IoWorkerRunnable(Runnable runnable) {
+        if (runnable == null) {
+            throw new NullPointerException("runnable");
+        }
+        this.runnable = runnable;
+    }
+
+    public void run() {
+        IN_IO_THREAD.set(Boolean.TRUE);
+        try {
+            runnable.run();
+        } finally {
+            IN_IO_THREAD.remove();
+        }
+    }
+}