From 2d935b58385369165a9c19100979403552f1d06b Mon Sep 17 00:00:00 2001
From: Sijie Guo <sijie@apache.org>
Date: Fri, 30 Jun 2017 00:43:49 -0700
Subject: [PATCH] Issue 221: Make netty server shutdown idempotent

---
 .../org/apache/bookkeeper/proto/BookieNettyServer.java     | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/bookkeeper-server/src/main/java/org/apache/bookkeeper/proto/BookieNettyServer.java b/bookkeeper-server/src/main/java/org/apache/bookkeeper/proto/BookieNettyServer.java
index 53fd334b747..22c3cffc206 100644
--- a/bookkeeper-server/src/main/java/org/apache/bookkeeper/proto/BookieNettyServer.java
+++ b/bookkeeper-server/src/main/java/org/apache/bookkeeper/proto/BookieNettyServer.java
@@ -85,6 +85,7 @@ class BookieNettyServer {
     final EventLoopGroup jvmEventLoopGroup;
     final RequestProcessor requestProcessor;
     final AtomicBoolean isRunning = new AtomicBoolean(false);
+    final AtomicBoolean isClosed = new AtomicBoolean(false);
     final Object suspensionLock = new Object();
     volatile boolean suspended = false;
     ChannelGroup allChannels;
@@ -279,6 +280,12 @@ void start() {
     void shutdown() {
         LOG.info("Shutting down BookieNettyServer");
         isRunning.set(false);
+
+        if (!isClosed.compareAndSet(false, true)) {
+            // the netty server is already closed.
+            return;
+        }
+
         allChannels.close().awaitUninterruptibly();
 
         if (eventLoopGroup != null) {