From e847ac0443ea1d7996b392d9adcfcd06e4094b78 Mon Sep 17 00:00:00 2001
From: Norman Maurer <norman_maurer@apple.com>
Date: Mon, 30 May 2016 20:45:37 +0200
Subject: [PATCH] Fix possible deadlock in
 DefaultChannelPipeline.destroyDown(...)

Motivation:

We need to ensure we not hold a lock while executor callHandlerRemoved(...) as this may lead to a deadlock if handlerRemoved(...) will call another method in DEfaultChannelPipeline from another thread that will need to obtain the lock as well and wait for the result.

Modifications:

Release the lock before call handlerRemoved0(...).

Result:

No more deadlock possible
---
 .../src/main/java/io/netty/channel/DefaultChannelPipeline.java  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java b/transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java
index 141c498da0..a6abec7df4 100644
--- a/transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java
+++ b/transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java
@@ -858,8 +858,8 @@ public class DefaultChannelPipeline implements ChannelPipeline {
             if (inEventLoop || executor.inEventLoop(currentThread)) {
                 synchronized (this) {
                     remove0(ctx);
-                    callHandlerRemoved0(ctx);
                 }
+                callHandlerRemoved0(ctx);
             } else {
                 final AbstractChannelHandlerContext finalCtx = ctx;
                 executor.execute(new OneTimeTask() {