PaperMC/Spigot-Server-Patches/0102-Avoid-blocking-on-Network-Manager-creation.patch
Shevchik c8dea96ee1
Prevent blocking on adding a new network manager (#3027)
Previous solution could still block network thread (while addPending is executing). This window is small, but removing it completely is better. This should probably also speed up concurrent adds, because no locking will be performed anymore.
The only possible downside is that adding elements one by one to synchronized list might be slower (But it's done while already locked, so maybe jvm will avoid additional locking?),
2020-03-14 11:20:50 +00:00

46 lines
2.7 KiB
Diff

From 55ced1105b5d5fe2f705ff0fdeeaa7f00fe95294 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 16 May 2016 23:19:16 -0400
Subject: [PATCH] Avoid blocking on Network Manager creation
Per Paper issue 294
diff --git a/src/main/java/net/minecraft/server/ServerConnection.java b/src/main/java/net/minecraft/server/ServerConnection.java
index e7e21685..404e7834 100644
--- a/src/main/java/net/minecraft/server/ServerConnection.java
+++ b/src/main/java/net/minecraft/server/ServerConnection.java
@@ -39,6 +39,15 @@ public class ServerConnection {
public volatile boolean c;
private final List<ChannelFuture> listeningChannels = Collections.synchronizedList(Lists.newArrayList());
private final List<NetworkManager> connectedChannels = Collections.synchronizedList(Lists.newArrayList());
+ // Paper start - prevent blocking on adding a new network manager while the server is ticking
+ private final java.util.Queue<NetworkManager> pending = new java.util.concurrent.ConcurrentLinkedQueue<>();
+ private void addPending() {
+ NetworkManager manager = null;
+ while ((manager = pending.poll()) != null) {
+ connectedChannels.add(manager);
+ }
+ }
+ // Paper end
public ServerConnection(MinecraftServer minecraftserver) {
this.e = minecraftserver;
@@ -73,7 +82,7 @@ public class ServerConnection {
channel.pipeline().addLast("timeout", new ReadTimeoutHandler(30)).addLast("legacy_query", new LegacyPingHandler(ServerConnection.this)).addLast("splitter", new PacketSplitter()).addLast("decoder", new PacketDecoder(EnumProtocolDirection.SERVERBOUND)).addLast("prepender", new PacketPrepender()).addLast("encoder", new PacketEncoder(EnumProtocolDirection.CLIENTBOUND));
NetworkManager networkmanager = new NetworkManager(EnumProtocolDirection.SERVERBOUND);
- ServerConnection.this.connectedChannels.add(networkmanager);
+ pending.add(networkmanager); // Paper
channel.pipeline().addLast("packet_handler", networkmanager);
networkmanager.setPacketListener(new HandshakeListener(ServerConnection.this.e, networkmanager));
}
@@ -112,6 +121,7 @@ public class ServerConnection {
synchronized (this.connectedChannels) {
// Spigot Start
+ this.addPending(); // Paper
// This prevents players from 'gaming' the server, and strategically relogging to increase their position in the tick order
if ( org.spigotmc.SpigotConfig.playerShuffle > 0 && MinecraftServer.currentTick % org.spigotmc.SpigotConfig.playerShuffle == 0 )
{
--
2.17.1