Add proper thread safety. Please let me know if this deadlocks your server.

CraftBukkit-Patches/0026-Netty.patch

@@ -1,4 +1,4 @@
-From 8794e1bc1ae9773a9f7c9943c7696a76e66691aa Mon Sep 17 00:00:00 2001
+From 2624cc163bed8a94b851c7dbc186a304ce63bff7 Mon Sep 17 00:00:00 2001
 From: md_5 <md_5@live.com.au>
 Date: Sun, 3 Feb 2013 10:24:33 +1100
 Subject: [PATCH] Netty
@@ -17,13 +17,13 @@ This commit is licensed under the Creative Commons Attribution-ShareAlike 3.0 Un
  .../net/minecraft/server/PendingConnection.java    |  15 +-
  .../net/minecraft/server/PlayerConnection.java     |   2 +-
  src/main/java/org/spigotmc/netty/CipherCodec.java  |  65 ++++++
- .../org/spigotmc/netty/NettyNetworkManager.java    | 211 ++++++++++++++++++
+ .../org/spigotmc/netty/NettyNetworkManager.java    | 221 ++++++++++++++++++
  .../org/spigotmc/netty/NettyServerConnection.java  | 105 +++++++++
  .../org/spigotmc/netty/NettySocketAdaptor.java     | 248 +++++++++++++++++++++
  .../java/org/spigotmc/netty/PacketDecoder.java     |  47 ++++
  .../java/org/spigotmc/netty/PacketEncoder.java     |  43 ++++
  .../java/org/spigotmc/netty/PacketListener.java    | 100 +++++++++
- 11 files changed, 841 insertions(+), 7 deletions(-)
+ 11 files changed, 851 insertions(+), 7 deletions(-)
  create mode 100644 src/main/java/org/spigotmc/netty/CipherCodec.java
  create mode 100644 src/main/java/org/spigotmc/netty/NettyNetworkManager.java
  create mode 100644 src/main/java/org/spigotmc/netty/NettyServerConnection.java
@@ -208,10 +208,10 @@ index 0000000..cfc0535
 +}
 diff --git a/src/main/java/org/spigotmc/netty/NettyNetworkManager.java b/src/main/java/org/spigotmc/netty/NettyNetworkManager.java
 new file mode 100644
-index 0000000..effd1ee
+index 0000000..81aa42e
 --- /dev/null
 +++ b/src/main/java/org/spigotmc/netty/NettyNetworkManager.java
-@@ -0,0 +1,211 @@
+@@ -0,0 +1,221 @@
 +package org.spigotmc.netty;
 +
 +import io.netty.channel.Channel;
@@ -247,8 +247,9 @@ index 0000000..effd1ee
 +    private static final PrivateKey key = server.F().getPrivate();
 +    private static final NettyServerConnection serverConnection = (NettyServerConnection) server.ae();
 +    /*========================================================================*/
-+    private Queue<Packet> syncPackets = new ConcurrentLinkedQueue<Packet>();
++    private final Object mutex = new Object();
-+    private volatile Channel channel;
++    private final Queue<Packet> syncPackets = new ConcurrentLinkedQueue<Packet>();
++    private Channel channel;
 +    private SocketAddress address;
 +    private Connection handler;
 +    private SecretKey secret;
@@ -258,6 +259,7 @@ index 0000000..effd1ee
 +
 +    @Override
 +    public void channelActive(ChannelHandlerContext ctx) throws Exception {
++        synchronized (mutex) {
 +            // Channel and address groundwork first
 +            channel = ctx.channel();
 +            address = channel.remoteAddress();
@@ -268,18 +270,22 @@ index 0000000..effd1ee
 +            // Finally register the connection
 +            serverConnection.pendingConnections.add((PendingConnection) handler);
 +        }
++    }
 +
 +    @Override
 +    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
++        synchronized (mutex) {
 +            if (dcReason == null || dcArgs == null) {
 +                a("disconnect.endOfStream", new Object[0]);
 +            }
 +            // Remove channel reference to indicate we are done
 +            channel = null;
 +        }
++    }
 +
 +    @Override
 +    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
++        synchronized (mutex) {
 +            // TODO: Remove this once we are more stable
 +            // Bukkit.getServer().getLogger().severe("======================= Start Netty Debug Log =======================");
 +            // Bukkit.getServer().getLogger().log(Level.SEVERE, "Error caught whilst handling " + channel, cause);
@@ -288,6 +294,7 @@ index 0000000..effd1ee
 +            // Disconnect with generic reason + exception
 +            a("disconnect.genericReason", new Object[]{"Internal exception: " + cause});
 +        }
++    }
 +
 +    @Override
 +    public void messageReceived(ChannelHandlerContext ctx, final Packet msg) throws Exception {
@@ -329,6 +336,7 @@ index 0000000..effd1ee
 +     * @param packet the packet to queue
 +     */
 +    public void queue(Packet packet) {
++        synchronized (mutex) {
 +            // Only send if channel is still connected
 +            if (channel != null) {
 +                // Process packet via handler
@@ -342,8 +350,6 @@ index 0000000..effd1ee
 +                        BufferedBlockCipher encrypt = NettyServerConnection.getCipher(true, secret);
 +                        BufferedBlockCipher decrypt = NettyServerConnection.getCipher(false, secret);
 +                        CipherCodec codec = new CipherCodec(encrypt, decrypt);
-+                    // Only add if the channel hasn't disconnected in the meantime
-+                    if (channel != null) {
 +                        channel.pipeline().addBefore("decoder", "cipher", codec);
 +                    }
 +                }
@@ -392,10 +398,12 @@ index 0000000..effd1ee
 +     * close. Close and release all resources associated with this connection.
 +     */
 +    public void d() {
++        synchronized (mutex) {
 +            if (channel != null) {
 +                channel.close();
 +            }
 +        }
++    }
 +
 +    /**
 +     * queueSize. Return the number of packets in the low priority queue. In a
@@ -416,12 +424,14 @@ index 0000000..effd1ee
 +     * exception which triggered the disconnect.
 +     */
 +    public void a(String reason, Object... arguments) {
++        synchronized (mutex) {
 +            if (channel != null) {
 +                dcReason = reason;
 +                dcArgs = arguments;
 +                channel.close();
 +            }
 +        }
++    }
 +}
 diff --git a/src/main/java/org/spigotmc/netty/NettyServerConnection.java b/src/main/java/org/spigotmc/netty/NettyServerConnection.java
 new file mode 100644