From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Aikar Date: Wed, 6 May 2020 04:53:35 -0400 Subject: [PATCH] Optimize Network Manager and add advanced packet support Adds ability for 1 packet to bundle other packets to follow it Adds ability for a packet to delay sending more packets until a state is ready. Removes synchronization from sending packets Removes processing packet queue off of main thread - for the few cases where it is allowed, order is not necessary nor should it even be happening concurrently in first place (handshaking/login/status) Ensures packets sent asynchronously are dispatched on main thread This helps ensure safety for ProtocolLib as packet listeners are commonly accessing world state. This will allow you to schedule a packet to be sent async, but itll be dispatched sync for packet listeners to process. This should solve some deadlock risks Also adds Netty Channel Flush Consolidation to reduce the amount of flushing Also avoids spamming closed channel exception by rechecking closed state in dispatch and then catch exceptions and close if they fire. Part of this commit was authored by: Spottedleaf diff --git a/src/main/java/net/minecraft/network/Connection.java b/src/main/java/net/minecraft/network/Connection.java index 3559f6c54e7674d3eaf023d2ceaee13edfcae5b2..a0d3d9e344f530b713167d0663634c40eefce5b5 100644 --- a/src/main/java/net/minecraft/network/Connection.java +++ b/src/main/java/net/minecraft/network/Connection.java @@ -97,6 +97,10 @@ public class Connection extends SimpleChannelInboundHandler> { public int protocolVersion; public java.net.InetSocketAddress virtualHost; private static boolean enableExplicitFlush = Boolean.getBoolean("paper.explicit-flush"); + // Optimize network + public boolean isPending = true; + public boolean queueImmunity = false; + public ConnectionProtocol protocol; // Paper end public Connection(PacketFlow side) { @@ -120,6 +124,7 @@ public class Connection extends SimpleChannelInboundHandler> { } public void setProtocol(ConnectionProtocol state) { + protocol = state; // Paper this.channel.attr(Connection.ATTRIBUTE_PROTOCOL).set(state); this.channel.config().setAutoRead(true); Connection.LOGGER.debug("Enabled auto read"); @@ -198,19 +203,87 @@ public class Connection extends SimpleChannelInboundHandler> { Validate.notNull(listener, "packetListener", new Object[0]); this.packetListener = listener; } + // Paper start + public net.minecraft.server.level.ServerPlayer getPlayer() { + if (packetListener instanceof ServerGamePacketListenerImpl) { + return ((ServerGamePacketListenerImpl) packetListener).player; + } else { + return null; + } + } + private static class InnerUtil { // Attempt to hide these methods from ProtocolLib so it doesn't accidently pick them up. + private static java.util.List buildExtraPackets(Packet packet) { + java.util.List extra = packet.getExtraPackets(); + if (extra == null || extra.isEmpty()) { + return null; + } + java.util.List ret = new java.util.ArrayList<>(1 + extra.size()); + buildExtraPackets0(extra, ret); + return ret; + } + + private static void buildExtraPackets0(java.util.List extraPackets, java.util.List into) { + for (Packet extra : extraPackets) { + into.add(extra); + java.util.List extraExtra = extra.getExtraPackets(); + if (extraExtra != null && !extraExtra.isEmpty()) { + buildExtraPackets0(extraExtra, into); + } + } + } + // Paper start + private static boolean canSendImmediate(Connection networkManager, Packet packet) { + return networkManager.isPending || networkManager.protocol != ConnectionProtocol.PLAY || + packet instanceof net.minecraft.network.protocol.game.ClientboundKeepAlivePacket || + packet instanceof net.minecraft.network.protocol.game.ClientboundChatPacket || + packet instanceof net.minecraft.network.protocol.game.ClientboundCommandSuggestionsPacket || + packet instanceof net.minecraft.network.protocol.game.ClientboundSetTitleTextPacket || + packet instanceof net.minecraft.network.protocol.game.ClientboundSetSubtitleTextPacket || + packet instanceof net.minecraft.network.protocol.game.ClientboundSetActionBarTextPacket || + packet instanceof net.minecraft.network.protocol.game.ClientboundSetTitlesAnimationPacket || + packet instanceof net.minecraft.network.protocol.game.ClientboundClearTitlesPacket || + packet instanceof net.minecraft.network.protocol.game.ClientboundBossEventPacket; + } + // Paper end + } + // Paper end public void send(Packet packet) { this.send(packet, (GenericFutureListener) null); } public void send(Packet packet, @Nullable GenericFutureListener> callback) { - if (this.isConnected()) { - this.flushQueue(); + // Paper start - handle oversized packets better + boolean connected = this.isConnected(); + if (!connected && !preparing) { + return; // Do nothing + } + packet.onPacketDispatch(getPlayer()); + if (connected && (InnerUtil.canSendImmediate(this, packet) || ( + net.minecraft.server.MCUtil.isMainThread() && packet.isReady() && this.queue.isEmpty() && + (packet.getExtraPackets() == null || packet.getExtraPackets().isEmpty()) + ))) { this.sendPacket(packet, callback); - } else { - this.queue.add(new Connection.PacketHolder(packet, callback)); + return; } + // write the packets to the queue, then flush - antixray hooks there already + java.util.List extraPackets = InnerUtil.buildExtraPackets(packet); + boolean hasExtraPackets = extraPackets != null && !extraPackets.isEmpty(); + if (!hasExtraPackets) { + this.queue.add(new Connection.PacketHolder(packet, callback)); + } else { + java.util.List packets = new java.util.ArrayList<>(1 + extraPackets.size()); + packets.add(new Connection.PacketHolder(packet, null)); // delay the future listener until the end of the extra packets + for (int i = 0, len = extraPackets.size(); i < len;) { + Packet extra = extraPackets.get(i); + boolean end = ++i == len; + packets.add(new Connection.PacketHolder(extra, end ? callback : null)); // append listener to the end + } + this.queue.addAll(packets); // atomic + } + this.flushQueue(); + // Paper end } private void sendPacket(Packet packet, @Nullable GenericFutureListener> callback) { @@ -238,33 +311,79 @@ public class Connection extends SimpleChannelInboundHandler> { this.setProtocol(packetState); } + // Paper start + net.minecraft.server.level.ServerPlayer player = getPlayer(); + if (!isConnected()) { + packet.onPacketDispatchFinish(player, null); + return; + } + + try { + // Paper end ChannelFuture channelfuture = this.channel.writeAndFlush(packet); if (callback != null) { channelfuture.addListener(callback); } + // Paper start + if (packet.hasFinishListener()) { + channelfuture.addListener((ChannelFutureListener) channelFuture -> packet.onPacketDispatchFinish(player, channelFuture)); + } + // Paper end channelfuture.addListener(ChannelFutureListener.FIRE_EXCEPTION_ON_FAILURE); + // Paper start + } catch (Exception e) { + LOGGER.error("NetworkException: " + player, e); + disconnect(new net.minecraft.network.chat.TranslatableComponent("disconnect.genericReason", "Internal Exception: " + e.getMessage())); + packet.onPacketDispatchFinish(player, null); + } + // Paper end } private ConnectionProtocol getCurrentProtocol() { return (ConnectionProtocol) this.channel.attr(Connection.ATTRIBUTE_PROTOCOL).get(); } - private void flushQueue() { - if (this.channel != null && this.channel.isOpen()) { - Queue queue = this.queue; - + // Paper start - rewrite this to be safer if ran off main thread + private boolean flushQueue() { // void -> boolean + if (!isConnected()) { + return true; + } + if (net.minecraft.server.MCUtil.isMainThread()) { + return processQueue(); + } else if (isPending) { + // Should only happen during login/status stages synchronized (this.queue) { - Connection.PacketHolder networkmanager_queuedpacket; - - while ((networkmanager_queuedpacket = (Connection.PacketHolder) this.queue.poll()) != null) { - this.sendPacket(networkmanager_queuedpacket.packet, networkmanager_queuedpacket.listener); - } + return this.processQueue(); + } + } + return false; + } + private boolean processQueue() { + if (this.queue.isEmpty()) return true; + // If we are on main, we are safe here in that nothing else should be processing queue off main anymore + // But if we are not on main due to login/status, the parent is synchronized on packetQueue + java.util.Iterator iterator = this.queue.iterator(); + while (iterator.hasNext()) { + PacketHolder queued = iterator.next(); // poll -> peek + + // Fix NPE (Spigot bug caused by handleDisconnection()) + if (queued == null) { + return true; + } + Packet packet = queued.packet; + if (!packet.isReady()) { + return false; + } else { + iterator.remove(); + this.sendPacket(packet, queued.listener); } } + return true; } + // Paper end public void tick() { this.flushQueue(); @@ -301,9 +420,22 @@ public class Connection extends SimpleChannelInboundHandler> { return this.address; } + // Paper start + public void clearPacketQueue() { + net.minecraft.server.level.ServerPlayer player = getPlayer(); + queue.forEach(queuedPacket -> { + Packet packet = queuedPacket.packet; + if (packet.hasFinishListener()) { + packet.onPacketDispatchFinish(player, null); + } + }); + queue.clear(); + } + // Paper end public void disconnect(Component disconnectReason) { // Spigot Start this.preparing = false; + clearPacketQueue(); // Paper // Spigot End if (this.channel.isOpen()) { this.channel.close(); // We can't wait as this may be called from an event loop. @@ -421,7 +553,7 @@ public class Connection extends SimpleChannelInboundHandler> { public void handleDisconnection() { if (this.channel != null && !this.channel.isOpen()) { if (this.disconnectionHandled) { - Connection.LOGGER.warn("handleDisconnection() called twice"); + //Connection.LOGGER.warn("handleDisconnection() called twice"); // Paper - Do not log useless message } else { this.disconnectionHandled = true; if (this.getDisconnectedReason() != null) { @@ -429,7 +561,7 @@ public class Connection extends SimpleChannelInboundHandler> { } else if (this.getPacketListener() != null) { this.getPacketListener().onDisconnect(new TranslatableComponent("multiplayer.disconnect.generic")); } - this.queue.clear(); // Free up packet queue. + clearPacketQueue(); // Paper // Paper start - Add PlayerConnectionCloseEvent final PacketListener packetListener = this.getPacketListener(); if (packetListener instanceof ServerGamePacketListenerImpl) { diff --git a/src/main/java/net/minecraft/network/protocol/Packet.java b/src/main/java/net/minecraft/network/protocol/Packet.java index 74bfe0d3942259c45702b099efdc4e101a4e3022..e8fcd56906d26f6dc87959e32c4c7c78cfea9658 100644 --- a/src/main/java/net/minecraft/network/protocol/Packet.java +++ b/src/main/java/net/minecraft/network/protocol/Packet.java @@ -9,6 +9,19 @@ public interface Packet { void handle(T listener); // Paper start + /** + * @param player Null if not at PLAY stage yet + */ + default void onPacketDispatch(@javax.annotation.Nullable net.minecraft.server.level.ServerPlayer player) {} + + /** + * @param player Null if not at PLAY stage yet + * @param future Can be null if packet was cancelled + */ + default void onPacketDispatchFinish(@javax.annotation.Nullable net.minecraft.server.level.ServerPlayer player, @javax.annotation.Nullable io.netty.channel.ChannelFuture future) {} + default boolean hasFinishListener() { return false; } + default boolean isReady() { return true; } + default java.util.List getExtraPackets() { return null; } default boolean packetTooLarge(net.minecraft.network.Connection manager) { return false; } diff --git a/src/main/java/net/minecraft/server/network/ServerConnectionListener.java b/src/main/java/net/minecraft/server/network/ServerConnectionListener.java index e174d9803e557470068f7893260d55a042888517..7c820a8f9ae85eb6941dce0e6296775fb331d720 100644 --- a/src/main/java/net/minecraft/server/network/ServerConnectionListener.java +++ b/src/main/java/net/minecraft/server/network/ServerConnectionListener.java @@ -63,10 +63,12 @@ public class ServerConnectionListener { final List connections = Collections.synchronizedList(Lists.newArrayList()); // Paper start - prevent blocking on adding a new network manager while the server is ticking private final java.util.Queue pending = new java.util.concurrent.ConcurrentLinkedQueue<>(); + private static final boolean disableFlushConsolidation = Boolean.getBoolean("Paper.disableFlushConsolidate"); // Paper private final void addPending() { Connection manager = null; while ((manager = pending.poll()) != null) { connections.add(manager); + manager.isPending = false; } } // Paper end @@ -101,6 +103,7 @@ public class ServerConnectionListener { ; } + if (!disableFlushConsolidation) channel.pipeline().addFirst(new io.netty.handler.flush.FlushConsolidationHandler()); // Paper channel.pipeline().addLast("timeout", new ReadTimeoutHandler(30)).addLast("legacy_query", new LegacyQueryHandler(ServerConnectionListener.this)).addLast("splitter", new Varint21FrameDecoder()).addLast("decoder", new PacketDecoder(PacketFlow.SERVERBOUND)).addLast("prepender", new Varint21LengthFieldPrepender()).addLast("encoder", new PacketEncoder(PacketFlow.CLIENTBOUND)); int j = ServerConnectionListener.this.server.getRateLimitPacketsPerSecond(); Object object = j > 0 ? new RateKickingConnection(j) : new Connection(PacketFlow.SERVERBOUND);