From c4ba12e8d44a23c9456a3abcefa396a44b80553a Mon Sep 17 00:00:00 2001
From: Trustin Lee <trustin@gmail.com>
Date: Thu, 23 Apr 2009 06:55:45 +0000
Subject: [PATCH] Ported the dead lock detector in DefaultChannelFuture to
 DefaultChannelGroupFuture.

---
 .../channel/group/DefaultChannelGroupFuture.java     | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/main/java/org/jboss/netty/channel/group/DefaultChannelGroupFuture.java b/src/main/java/org/jboss/netty/channel/group/DefaultChannelGroupFuture.java
index 659f26de32..fc4ffd86b0 100644
--- a/src/main/java/org/jboss/netty/channel/group/DefaultChannelGroupFuture.java
+++ b/src/main/java/org/jboss/netty/channel/group/DefaultChannelGroupFuture.java
@@ -38,6 +38,7 @@ import org.jboss.netty.channel.ChannelFuture;
 import org.jboss.netty.channel.ChannelFutureListener;
 import org.jboss.netty.logging.InternalLogger;
 import org.jboss.netty.logging.InternalLoggerFactory;
+import org.jboss.netty.util.internal.IoWorkerRunnable;
 
 /**
  * The default {@link ChannelGroupFuture} implementation.
@@ -210,6 +211,7 @@ public class DefaultChannelGroupFuture implements ChannelGroupFuture {
     public ChannelGroupFuture await() throws InterruptedException {
         synchronized (this) {
             while (!done) {
+                checkDeadLock();
                 waiters++;
                 try {
                     this.wait();
@@ -233,6 +235,7 @@ public class DefaultChannelGroupFuture implements ChannelGroupFuture {
     public ChannelGroupFuture awaitUninterruptibly() {
         synchronized (this) {
             while (!done) {
+                checkDeadLock();
                 waiters++;
                 try {
                     this.wait();
@@ -274,6 +277,7 @@ public class DefaultChannelGroupFuture implements ChannelGroupFuture {
                 return done;
             }
 
+            checkDeadLock();
             waiters++;
             try {
                 for (;;) {
@@ -300,6 +304,14 @@ public class DefaultChannelGroupFuture implements ChannelGroupFuture {
         }
     }
 
+    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.");
+        }
+    }
+
     boolean setDone() {
         synchronized (this) {
             // Allow only once.