From 17334a0a427458f0387f708825d23d756d36a2f8 Mon Sep 17 00:00:00 2001
From: Norman Maurer <nmaurer@redhat.com>
Date: Tue, 15 Apr 2014 06:40:15 +0200
Subject: [PATCH] [#2390] Minimize memory usage of NioDatagramChannel

Motivation:
At the moment we create a HashMap that holds the MembershipKeys for multicast with every NioDatagramChannel even when most people not need it at al

Modifications:
Lazy create the HashMap when needed.

Result:
Less memory usage and less object creation
---
 .../netty/channel/socket/nio/NioDatagramChannel.java   | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java b/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java
index aa71a8b746..b3bb45281e 100644
--- a/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java
+++ b/transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java
@@ -64,9 +64,8 @@ public final class NioDatagramChannel
     private static final SelectorProvider DEFAULT_SELECTOR_PROVIDER = SelectorProvider.provider();
 
     private final DatagramChannelConfig config;
-    private final Map<InetAddress, List<MembershipKey>> memberships =
-            new HashMap<InetAddress, List<MembershipKey>>();
 
+    private Map<InetAddress, List<MembershipKey>> memberships;
     private RecvByteBufAllocator.Handle allocHandle;
 
     private static DatagramChannel newSocket(SelectorProvider provider) {
@@ -367,7 +366,12 @@ public final class NioDatagramChannel
             }
 
             synchronized (this) {
-                List<MembershipKey> keys = memberships.get(multicastAddress);
+                List<MembershipKey> keys = null;
+                if (memberships == null) {
+                    memberships = new HashMap<InetAddress, List<MembershipKey>>();
+                } else {
+                    keys = memberships.get(multicastAddress);
+                }
                 if (keys == null) {
                     keys = new ArrayList<MembershipKey>();
                     memberships.put(multicastAddress, keys);