From a159d3ebac5812e4f6c1394d81b853b0ac140510 Mon Sep 17 00:00:00 2001
From: Norman Maurer <nmaurer@redhat.com>
Date: Tue, 19 Nov 2013 17:57:25 +0100
Subject: [PATCH] [#1994] DefaultPromise.cancel() should reuse
 CancellationException for performance reasons

---
 .../java/io/netty/util/concurrent/DefaultPromise.java    | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/common/src/main/java/io/netty/util/concurrent/DefaultPromise.java b/common/src/main/java/io/netty/util/concurrent/DefaultPromise.java
index 792546a82f..3a3940b793 100644
--- a/common/src/main/java/io/netty/util/concurrent/DefaultPromise.java
+++ b/common/src/main/java/io/netty/util/concurrent/DefaultPromise.java
@@ -16,6 +16,7 @@
 package io.netty.util.concurrent;
 
 import io.netty.util.Signal;
+import io.netty.util.internal.EmptyArrays;
 import io.netty.util.internal.PlatformDependent;
 import io.netty.util.internal.StringUtil;
 import io.netty.util.internal.logging.InternalLogger;
@@ -41,6 +42,12 @@ public class DefaultPromise<V> extends AbstractFuture<V> implements Promise<V> {
     };
     private static final Signal SUCCESS = Signal.valueOf(DefaultPromise.class.getName() + ".SUCCESS");
     private static final Signal UNCANCELLABLE = Signal.valueOf(DefaultPromise.class.getName() + ".UNCANCELLABLE");
+    private static final CauseHolder CANCELLATION_CAUSE_HOLDER = new CauseHolder(new CancellationException());
+
+    static {
+        CANCELLATION_CAUSE_HOLDER.cause.setStackTrace(EmptyArrays.EMPTY_STACK_TRACE);
+    }
+
     private final EventExecutor executor;
 
     private volatile Object result;
@@ -424,7 +431,7 @@ public class DefaultPromise<V> extends AbstractFuture<V> implements Promise<V> {
                 return false;
             }
 
-            this.result = new CauseHolder(new CancellationException());
+            this.result = CANCELLATION_CAUSE_HOLDER;
             if (hasWaiters()) {
                 notifyAll();
             }