Addition of SendThread class and other related adjustments.

L2J_Mobius_01.0_Ertheia/dist/game/config/Server.ini

@@ -36,6 +36,11 @@ GameserverPort = 7777
 # Default: 100
 ClientReadPoolSize = 100
 
+# Client pool size for sending server packets.
+# Each pool is executed on a separate thread.
+# Default: 25
+ClientSendPoolSize = 25
+
 # Client pool size for executing client packets.
 # Each pool is executed on a separate thread.
 # Default: 50

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/Config.java

@@ -768,6 +768,7 @@ public class Config
 	public static int LOGIN_BLOCK_AFTER_BAN;
 	public static String GAMESERVER_HOSTNAME;
 	public static int CLIENT_READ_POOL_SIZE;
+	public static int CLIENT_SEND_POOL_SIZE;
 	public static int CLIENT_EXECUTE_POOL_SIZE;
 	public static int PACKET_QUEUE_LIMIT;
 	public static boolean PACKET_FLOOD_DISCONNECT;
@@ -1362,6 +1363,7 @@ public class Config
 			GAME_SERVER_LOGIN_PORT = serverConfig.getInt("LoginPort", 9014);
 			GAME_SERVER_LOGIN_HOST = serverConfig.getString("LoginHost", "127.0.0.1");
 			CLIENT_READ_POOL_SIZE = serverConfig.getInt("ClientReadPoolSize", 100);
+			CLIENT_SEND_POOL_SIZE = serverConfig.getInt("ClientSendPoolSize", 25);
 			CLIENT_EXECUTE_POOL_SIZE = serverConfig.getInt("ClientExecutePoolSize", 50);
 			PACKET_QUEUE_LIMIT = serverConfig.getInt("PacketQueueLimit", 80);
 			PACKET_FLOOD_DISCONNECT = serverConfig.getBoolean("PacketFloodDisconnect", false);

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/commons/network/ExecuteThread.java

@@ -16,6 +16,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 	
 	private final Set<E> _pool;
 	private final PacketHandlerInterface<E> _packetHandler;
+	private boolean _idle;
 	
 	public ExecuteThread(Set<E> pool, PacketHandlerInterface<E> packetHandler)
 	{
@@ -31,6 +32,8 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -40,7 +43,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						continue ITERATE;
 					}
 					
-					final byte[] data = client.getPacketData().poll();
+					final byte[] data = client.getReceivedData().poll();
 					if (data == null)
 					{
 						continue ITERATE;
@@ -64,16 +67,29 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						}
 					}
 					_packetHandler.handle(client, new ReadablePacket(data));
+					
+					_idle = false;
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
 				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/commons/network/NetClient.java

@@ -15,12 +15,15 @@ public class NetClient
 {
 	protected static final Logger LOGGER = Logger.getLogger(NetClient.class.getName());
 	
+	private final Queue<byte[]> _receivedData = new ConcurrentLinkedQueue<>();
+	private final Queue<WritablePacket> _sendPacketQueue = new ConcurrentLinkedQueue<>();
+	
 	private String _ip;
 	private Socket _socket;
 	private InputStream _inputStream;
 	private OutputStream _outputStream;
 	private NetConfig _netConfig;
-	private Queue<byte[]> _packetData;
+	
 	private byte[] _pendingData;
 	private int _pendingPacketSize;
 	
@@ -33,7 +36,6 @@ public class NetClient
 	{
 		_socket = socket;
 		_netConfig = netConfig;
-		_packetData = new ConcurrentLinkedQueue<>();
 		_ip = socket.getInetAddress().toString().substring(1); // Trim out /127.0.0.1
 		
 		try
@@ -82,10 +84,8 @@ public class NetClient
 			}
 		}
 		
-		if (_packetData != null)
+		_receivedData.clear();
-		{
+		_sendPacketQueue.clear();
-			_packetData.clear();
-		}
 		
 		if (_pendingData != null)
 		{
@@ -97,10 +97,10 @@ public class NetClient
 	 * Add packet data to the queue.
 	 * @param data
 	 */
-	public void addPacketData(byte[] data)
+	public void addReceivedData(byte[] data)
 	{
 		// Check packet flooding.
-		final int size = _packetData.size();
+		final int size = _receivedData.size();
 		if (size >= _netConfig.getPacketQueueLimit())
 		{
 			if (_netConfig.isPacketFloodDisconnect())
@@ -127,15 +127,15 @@ public class NetClient
 		}
 		
 		// Add to queue.
-		_packetData.add(data);
+		_receivedData.add(data);
 	}
 	
 	/**
-	 * @return the pending packet data.
+	 * @return the pending received data.
 	 */
-	public Queue<byte[]> getPacketData()
+	public Queue<byte[]> getReceivedData()
 	{
-		return _packetData;
+		return _receivedData;
 	}
 	
 	/**
@@ -172,34 +172,21 @@ public class NetClient
 		_pendingPacketSize = pendingPacketSize;
 	}
 	
+	/**
+	 * @return the writable packet queue waiting to be sent.
+	 */
+	public Queue<WritablePacket> getSendPacketQueue()
+	{
+		return _sendPacketQueue;
+	}
+	
 	/**
 	 * Sends a packet over the network using the default encryption.
 	 * @param packet The packet to send.
 	 */
 	public void sendPacket(WritablePacket packet)
 	{
-		if ((_socket == null) || !_socket.isConnected())
+		_sendPacketQueue.add(packet);
-		{
-			return;
-		}
-		
-		final byte[] sendableBytes = packet.getSendableBytes(getEncryption());
-		if (sendableBytes == null)
-		{
-			return;
-		}
-		
-		try
-		{
-			synchronized (this)
-			{
-				_outputStream.write(sendableBytes);
-				_outputStream.flush();
-			}
-		}
-		catch (Exception ignored)
-		{
-		}
 	}
 	
 	/**

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/commons/network/NetConfig.java

@@ -7,6 +7,7 @@ package org.l2jmobius.commons.network;
 public class NetConfig
 {
 	private int _readPoolSize = 100;
+	private int _sendPoolSize = 25;
 	private int _executePoolSize = 50;
 	private int _packetQueueLimit = 80;
 	private boolean _packetFloodDisconnect = false;
@@ -32,6 +33,23 @@ public class NetConfig
 		_readPoolSize = clientPoolSize;
 	}
 	
+	/**
+	 * @return the NetClient pool size for sending server packets.
+	 */
+	public int getSendPoolSize()
+	{
+		return _sendPoolSize;
+	}
+	
+	/**
+	 * Sets the NetClient pool size for sending server packets.
+	 * @param clientPoolSize
+	 */
+	public void setSendPoolSize(int clientPoolSize)
+	{
+		_sendPoolSize = clientPoolSize;
+	}
+	
 	/**
 	 * @return the NetClient pool size for executing client packets.
 	 */

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/commons/network/NetServer.java

@@ -20,6 +20,7 @@ public class NetServer<E extends NetClient>
 	protected static final Logger LOGGER = Logger.getLogger(NetServer.class.getName());
 	
 	protected final List<Set<E>> _clientReadPools = new LinkedList<>();
+	protected final List<Set<E>> _clientSendPools = new LinkedList<>();
 	protected final List<Set<E>> _clientExecutePools = new LinkedList<>();
 	protected final NetConfig _netConfig = new NetConfig();
 	protected final String _hostname;
@@ -155,6 +156,35 @@ public class NetServer<E extends NetClient>
 							_clientReadPools.add(newReadPool);
 						}
 						
+						// Add to send pool.
+						
+						// Find a pool that is not full.
+						boolean sendPoolFound = false;
+						SEND_POOLS: for (Set<E> pool : _clientSendPools)
+						{
+							if (pool.size() < _netConfig.getSendPoolSize())
+							{
+								pool.add(client);
+								sendPoolFound = true;
+								break SEND_POOLS;
+							}
+						}
+						
+						// All pools are full.
+						if (!sendPoolFound)
+						{
+							// Create a new client pool.
+							final Set<E> newSendPool = ConcurrentHashMap.newKeySet(_netConfig.getSendPoolSize());
+							newSendPool.add(client);
+							// Create a new task for the new pool.
+							final Thread sendThread = new Thread(new SendThread<>(newSendPool), _name + ": Packet send thread " + _clientSendPools.size());
+							sendThread.setPriority(Thread.MAX_PRIORITY);
+							sendThread.setDaemon(true);
+							sendThread.start();
+							// Add the new pool to the pool list.
+							_clientSendPools.add(newSendPool);
+						}
+						
 						// Add to execute pool.
 						
 						// Find a pool that is not full.

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/commons/network/ReadThread.java

@@ -14,6 +14,7 @@ public class ReadThread<E extends NetClient> implements Runnable
 	private final Set<E> _pool;
 	private final byte[] _sizeBuffer = new byte[2]; // Reusable size buffer.
 	private final byte[] _pendingSizeBuffer = new byte[1]; // Reusable pending size buffer.
+	private boolean _idle;
 	
 	public ReadThread(Set<E> pool)
 	{
@@ -28,6 +29,8 @@ public class ReadThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -80,14 +83,16 @@ public class ReadThread<E extends NetClient> implements Runnable
 									// Read was complete.
 									if (currentSize >= pendingPacketSize)
 									{
-										// Add packet data to client.
+										// Add received data to client.
-										client.addPacketData(mergedData);
+										client.addReceivedData(mergedData);
 										client.setPendingData(null);
 									}
 									else
 									{
 										client.setPendingData(mergedData);
 									}
+									
+									_idle = false;
 								}
 							}
 							continue ITERATE;
@@ -188,10 +193,12 @@ public class ReadThread<E extends NetClient> implements Runnable
 											client.setPendingData(pendindBytes);
 											client.setPendingPacketSize(packetSize);
 										}
-										else // Add packet data to client.
+										else // Add received data to client.
 										{
-											client.addPacketData(packetData);
+											client.addReceivedData(packetData);
 										}
+										
+										_idle = false;
 									}
 								}
 							}
@@ -206,15 +213,26 @@ public class ReadThread<E extends NetClient> implements Runnable
 						onDisconnection(client);
 					}
 				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/commons/network/SendThread.java

@@ -0,0 +1,106 @@
+package org.l2jmobius.commons.network;
+
+import java.io.OutputStream;
+import java.net.Socket;
+import java.util.Queue;
+import java.util.Set;
+
+/**
+ * @author Pantelis Andrianakis
+ * @since June 22nd 2023
+ * @param <E> extends NetClient
+ */
+public class SendThread<E extends NetClient> implements Runnable
+{
+	// Throttle packets sent per cycle to limit flooding from waiting one client.
+	private static final int MAX_PACKETS_SENT_PER_CYCLE = 2000;
+	
+	private final Set<E> _pool;
+	private boolean _idle;
+	
+	public SendThread(Set<E> pool)
+	{
+		_pool = pool;
+	}
+	
+	@Override
+	public void run()
+	{
+		while (true)
+		{
+			// No need to iterate when pool is empty.
+			if (!_pool.isEmpty())
+			{
+				_idle = true;
+				
+				// Iterate client pool.
+				ITERATE: for (E client : _pool)
+				{
+					final Socket socket = client.getSocket();
+					if (socket == null)
+					{
+						_pool.remove(client);
+						continue ITERATE;
+					}
+					
+					try
+					{
+						final Queue<WritablePacket> packetQueue = client.getSendPacketQueue();
+						if (packetQueue.isEmpty())
+						{
+							continue ITERATE;
+						}
+						
+						final OutputStream outputStream = client.getOutputStream();
+						SEND_CYCLE: for (int count = 0; count < MAX_PACKETS_SENT_PER_CYCLE; count++)
+						{
+							final WritablePacket writablePacket = packetQueue.poll();
+							if (writablePacket == null)
+							{
+								continue ITERATE;
+							}
+							
+							final byte[] sendableBytes = writablePacket.getSendableBytes(client.getEncryption());
+							if (sendableBytes == null)
+							{
+								continue SEND_CYCLE;
+							}
+							
+							// Send the packet data.
+							outputStream.write(sendableBytes);
+							outputStream.flush();
+							
+							// Run packet implementation.
+							writablePacket.run();
+							
+							_idle = false;
+						}
+					}
+					catch (Exception ignored)
+					{
+					}
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+			else // Remain idle for 1 second.
+			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+		}
+	}
+}

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/commons/network/WritablePacket.java

@@ -223,6 +223,14 @@ public abstract class WritablePacket
 		// Overridden by server implementation.
 	}
 	
+	/**
+	 * Method that runs after packet is sent.
+	 */
+	public void run()
+	{
+		// Overridden by server implementation.
+	}
+	
 	/**
 	 * @return <b>byte[]</b> of the sendable packet data, including a size header.
 	 */

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/gameserver/GameServer.java

@@ -456,6 +456,7 @@ public class GameServer
 		final NetServer<GameClient> server = new NetServer<>(Config.GAMESERVER_HOSTNAME, Config.PORT_GAME, new PacketHandler(), GameClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(Config.CLIENT_READ_POOL_SIZE);
+		server.getNetConfig().setSendPoolSize(Config.CLIENT_SEND_POOL_SIZE);
 		server.getNetConfig().setExecutePoolSize(Config.CLIENT_EXECUTE_POOL_SIZE);
 		server.getNetConfig().setPacketQueueLimit(Config.PACKET_QUEUE_LIMIT);
 		server.getNetConfig().setPacketFloodDisconnect(Config.PACKET_FLOOD_DISCONNECT);

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/gameserver/network/GameClient.java

@@ -20,8 +20,6 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.util.List;
-import java.util.Queue;
-import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -66,7 +64,6 @@ public class GameClient extends NetClient
 {
 	protected static final Logger LOGGER_ACCOUNTING = Logger.getLogger("accounting");
 	
-	private final Queue<ServerPacket> _pendingPackets = new ConcurrentLinkedQueue<>();
 	private final FloodProtectors _floodProtectors = new FloodProtectors(this);
 	private final ReentrantLock _playerLock = new ReentrantLock();
 	private ConnectionState _connectionState = ConnectionState.CONNECTED;
@@ -218,16 +215,11 @@ public class GameClient extends NetClient
 			}
 		}
 		
-		// Keep the order of packets if sent by multiple threads.
+		// Used by packet run() method.
-		_pendingPackets.add(packet);
+		packet.setPlayer(_player);
-		synchronized (_pendingPackets)
+		
-		{
+		// Send the packet data.
-			// Send the packet data.
+		super.sendPacket(packet);
-			super.sendPacket(packet);
-			
-			// Run packet implementation.
-			packet.run(_player);
-		}
 	}
 	
 	public void sendPacket(SystemMessageId systemMessageId)

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/gameserver/network/serverpackets/AbstractHtmlPacket.java

@@ -131,12 +131,14 @@ public abstract class AbstractHtmlPacket extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.clearHtmlActions(getScope());
 		}
+		
 		if (_disabledValidation)
 		{
 			return;

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/gameserver/network/serverpackets/CreatureSay.java

@@ -162,8 +162,9 @@ public class CreatureSay extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.broadcastSnoop(_chatType, _senderName, _text);

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/gameserver/network/serverpackets/ServerPacket.java

@@ -112,12 +112,22 @@ public abstract class ServerPacket extends WritablePacket
 		super(initialSize);
 	}
 	
+	private Player _player;
+	
 	/**
-	 * Method that runs after packet is sent.
+	 * @return the Player
-	 * @param player
 	 */
-	public void run(Player player)
+	public Player getPlayer()
 	{
+		return _player;
+	}
+	
+	/**
+	 * @param player the Player to set.
+	 */
+	public void setPlayer(Player player)
+	{
+		_player = player;
 	}
 	
 	protected void writeOptionalInt(int value)

L2J_Mobius_01.0_Ertheia/java/org/l2jmobius/loginserver/LoginServer.java

@@ -136,6 +136,7 @@ public class LoginServer
 		final NetServer<LoginClient> server = new NetServer<>(Config.LOGIN_BIND_ADDRESS, Config.PORT_LOGIN, new LoginPacketHandler(), LoginClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(2000);
+		server.getNetConfig().setSendPoolSize(2000);
 		server.getNetConfig().setExecutePoolSize(2000);
 		server.getNetConfig().setPacketQueueLimit(10);
 		server.getNetConfig().setPacketFloodDisconnect(true);

L2J_Mobius_02.5_Underground/dist/game/config/Server.ini

@@ -36,6 +36,11 @@ GameserverPort = 7777
 # Default: 100
 ClientReadPoolSize = 100
 
+# Client pool size for sending server packets.
+# Each pool is executed on a separate thread.
+# Default: 25
+ClientSendPoolSize = 25
+
 # Client pool size for executing client packets.
 # Each pool is executed on a separate thread.
 # Default: 50

L2J_Mobius_02.5_Underground/java/org/l2jmobius/Config.java

@@ -779,6 +779,7 @@ public class Config
 	public static int LOGIN_BLOCK_AFTER_BAN;
 	public static String GAMESERVER_HOSTNAME;
 	public static int CLIENT_READ_POOL_SIZE;
+	public static int CLIENT_SEND_POOL_SIZE;
 	public static int CLIENT_EXECUTE_POOL_SIZE;
 	public static int PACKET_QUEUE_LIMIT;
 	public static boolean PACKET_FLOOD_DISCONNECT;
@@ -1374,6 +1375,7 @@ public class Config
 			GAME_SERVER_LOGIN_PORT = serverConfig.getInt("LoginPort", 9014);
 			GAME_SERVER_LOGIN_HOST = serverConfig.getString("LoginHost", "127.0.0.1");
 			CLIENT_READ_POOL_SIZE = serverConfig.getInt("ClientReadPoolSize", 100);
+			CLIENT_SEND_POOL_SIZE = serverConfig.getInt("ClientSendPoolSize", 25);
 			CLIENT_EXECUTE_POOL_SIZE = serverConfig.getInt("ClientExecutePoolSize", 50);
 			PACKET_QUEUE_LIMIT = serverConfig.getInt("PacketQueueLimit", 80);
 			PACKET_FLOOD_DISCONNECT = serverConfig.getBoolean("PacketFloodDisconnect", false);

L2J_Mobius_02.5_Underground/java/org/l2jmobius/commons/network/ExecuteThread.java

@@ -16,6 +16,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 	
 	private final Set<E> _pool;
 	private final PacketHandlerInterface<E> _packetHandler;
+	private boolean _idle;
 	
 	public ExecuteThread(Set<E> pool, PacketHandlerInterface<E> packetHandler)
 	{
@@ -31,6 +32,8 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -40,7 +43,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						continue ITERATE;
 					}
 					
-					final byte[] data = client.getPacketData().poll();
+					final byte[] data = client.getReceivedData().poll();
 					if (data == null)
 					{
 						continue ITERATE;
@@ -64,16 +67,29 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						}
 					}
 					_packetHandler.handle(client, new ReadablePacket(data));
+					
+					_idle = false;
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
 				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_02.5_Underground/java/org/l2jmobius/commons/network/NetClient.java

@@ -15,12 +15,15 @@ public class NetClient
 {
 	protected static final Logger LOGGER = Logger.getLogger(NetClient.class.getName());
 	
+	private final Queue<byte[]> _receivedData = new ConcurrentLinkedQueue<>();
+	private final Queue<WritablePacket> _sendPacketQueue = new ConcurrentLinkedQueue<>();
+	
 	private String _ip;
 	private Socket _socket;
 	private InputStream _inputStream;
 	private OutputStream _outputStream;
 	private NetConfig _netConfig;
-	private Queue<byte[]> _packetData;
+	
 	private byte[] _pendingData;
 	private int _pendingPacketSize;
 	
@@ -33,7 +36,6 @@ public class NetClient
 	{
 		_socket = socket;
 		_netConfig = netConfig;
-		_packetData = new ConcurrentLinkedQueue<>();
 		_ip = socket.getInetAddress().toString().substring(1); // Trim out /127.0.0.1
 		
 		try
@@ -82,10 +84,8 @@ public class NetClient
 			}
 		}
 		
-		if (_packetData != null)
+		_receivedData.clear();
-		{
+		_sendPacketQueue.clear();
-			_packetData.clear();
-		}
 		
 		if (_pendingData != null)
 		{
@@ -97,10 +97,10 @@ public class NetClient
 	 * Add packet data to the queue.
 	 * @param data
 	 */
-	public void addPacketData(byte[] data)
+	public void addReceivedData(byte[] data)
 	{
 		// Check packet flooding.
-		final int size = _packetData.size();
+		final int size = _receivedData.size();
 		if (size >= _netConfig.getPacketQueueLimit())
 		{
 			if (_netConfig.isPacketFloodDisconnect())
@@ -127,15 +127,15 @@ public class NetClient
 		}
 		
 		// Add to queue.
-		_packetData.add(data);
+		_receivedData.add(data);
 	}
 	
 	/**
-	 * @return the pending packet data.
+	 * @return the pending received data.
 	 */
-	public Queue<byte[]> getPacketData()
+	public Queue<byte[]> getReceivedData()
 	{
-		return _packetData;
+		return _receivedData;
 	}
 	
 	/**
@@ -172,34 +172,21 @@ public class NetClient
 		_pendingPacketSize = pendingPacketSize;
 	}
 	
+	/**
+	 * @return the writable packet queue waiting to be sent.
+	 */
+	public Queue<WritablePacket> getSendPacketQueue()
+	{
+		return _sendPacketQueue;
+	}
+	
 	/**
 	 * Sends a packet over the network using the default encryption.
 	 * @param packet The packet to send.
 	 */
 	public void sendPacket(WritablePacket packet)
 	{
-		if ((_socket == null) || !_socket.isConnected())
+		_sendPacketQueue.add(packet);
-		{
-			return;
-		}
-		
-		final byte[] sendableBytes = packet.getSendableBytes(getEncryption());
-		if (sendableBytes == null)
-		{
-			return;
-		}
-		
-		try
-		{
-			synchronized (this)
-			{
-				_outputStream.write(sendableBytes);
-				_outputStream.flush();
-			}
-		}
-		catch (Exception ignored)
-		{
-		}
 	}
 	
 	/**

L2J_Mobius_02.5_Underground/java/org/l2jmobius/commons/network/NetConfig.java

@@ -7,6 +7,7 @@ package org.l2jmobius.commons.network;
 public class NetConfig
 {
 	private int _readPoolSize = 100;
+	private int _sendPoolSize = 25;
 	private int _executePoolSize = 50;
 	private int _packetQueueLimit = 80;
 	private boolean _packetFloodDisconnect = false;
@@ -32,6 +33,23 @@ public class NetConfig
 		_readPoolSize = clientPoolSize;
 	}
 	
+	/**
+	 * @return the NetClient pool size for sending server packets.
+	 */
+	public int getSendPoolSize()
+	{
+		return _sendPoolSize;
+	}
+	
+	/**
+	 * Sets the NetClient pool size for sending server packets.
+	 * @param clientPoolSize
+	 */
+	public void setSendPoolSize(int clientPoolSize)
+	{
+		_sendPoolSize = clientPoolSize;
+	}
+	
 	/**
 	 * @return the NetClient pool size for executing client packets.
 	 */

L2J_Mobius_02.5_Underground/java/org/l2jmobius/commons/network/NetServer.java

@@ -20,6 +20,7 @@ public class NetServer<E extends NetClient>
 	protected static final Logger LOGGER = Logger.getLogger(NetServer.class.getName());
 	
 	protected final List<Set<E>> _clientReadPools = new LinkedList<>();
+	protected final List<Set<E>> _clientSendPools = new LinkedList<>();
 	protected final List<Set<E>> _clientExecutePools = new LinkedList<>();
 	protected final NetConfig _netConfig = new NetConfig();
 	protected final String _hostname;
@@ -155,6 +156,35 @@ public class NetServer<E extends NetClient>
 							_clientReadPools.add(newReadPool);
 						}
 						
+						// Add to send pool.
+						
+						// Find a pool that is not full.
+						boolean sendPoolFound = false;
+						SEND_POOLS: for (Set<E> pool : _clientSendPools)
+						{
+							if (pool.size() < _netConfig.getSendPoolSize())
+							{
+								pool.add(client);
+								sendPoolFound = true;
+								break SEND_POOLS;
+							}
+						}
+						
+						// All pools are full.
+						if (!sendPoolFound)
+						{
+							// Create a new client pool.
+							final Set<E> newSendPool = ConcurrentHashMap.newKeySet(_netConfig.getSendPoolSize());
+							newSendPool.add(client);
+							// Create a new task for the new pool.
+							final Thread sendThread = new Thread(new SendThread<>(newSendPool), _name + ": Packet send thread " + _clientSendPools.size());
+							sendThread.setPriority(Thread.MAX_PRIORITY);
+							sendThread.setDaemon(true);
+							sendThread.start();
+							// Add the new pool to the pool list.
+							_clientSendPools.add(newSendPool);
+						}
+						
 						// Add to execute pool.
 						
 						// Find a pool that is not full.

L2J_Mobius_02.5_Underground/java/org/l2jmobius/commons/network/ReadThread.java

@@ -14,6 +14,7 @@ public class ReadThread<E extends NetClient> implements Runnable
 	private final Set<E> _pool;
 	private final byte[] _sizeBuffer = new byte[2]; // Reusable size buffer.
 	private final byte[] _pendingSizeBuffer = new byte[1]; // Reusable pending size buffer.
+	private boolean _idle;
 	
 	public ReadThread(Set<E> pool)
 	{
@@ -28,6 +29,8 @@ public class ReadThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -80,14 +83,16 @@ public class ReadThread<E extends NetClient> implements Runnable
 									// Read was complete.
 									if (currentSize >= pendingPacketSize)
 									{
-										// Add packet data to client.
+										// Add received data to client.
-										client.addPacketData(mergedData);
+										client.addReceivedData(mergedData);
 										client.setPendingData(null);
 									}
 									else
 									{
 										client.setPendingData(mergedData);
 									}
+									
+									_idle = false;
 								}
 							}
 							continue ITERATE;
@@ -188,10 +193,12 @@ public class ReadThread<E extends NetClient> implements Runnable
 											client.setPendingData(pendindBytes);
 											client.setPendingPacketSize(packetSize);
 										}
-										else // Add packet data to client.
+										else // Add received data to client.
 										{
-											client.addPacketData(packetData);
+											client.addReceivedData(packetData);
 										}
+										
+										_idle = false;
 									}
 								}
 							}
@@ -206,15 +213,26 @@ public class ReadThread<E extends NetClient> implements Runnable
 						onDisconnection(client);
 					}
 				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_02.5_Underground/java/org/l2jmobius/commons/network/SendThread.java

@@ -0,0 +1,106 @@
+package org.l2jmobius.commons.network;
+
+import java.io.OutputStream;
+import java.net.Socket;
+import java.util.Queue;
+import java.util.Set;
+
+/**
+ * @author Pantelis Andrianakis
+ * @since June 22nd 2023
+ * @param <E> extends NetClient
+ */
+public class SendThread<E extends NetClient> implements Runnable
+{
+	// Throttle packets sent per cycle to limit flooding from waiting one client.
+	private static final int MAX_PACKETS_SENT_PER_CYCLE = 2000;
+	
+	private final Set<E> _pool;
+	private boolean _idle;
+	
+	public SendThread(Set<E> pool)
+	{
+		_pool = pool;
+	}
+	
+	@Override
+	public void run()
+	{
+		while (true)
+		{
+			// No need to iterate when pool is empty.
+			if (!_pool.isEmpty())
+			{
+				_idle = true;
+				
+				// Iterate client pool.
+				ITERATE: for (E client : _pool)
+				{
+					final Socket socket = client.getSocket();
+					if (socket == null)
+					{
+						_pool.remove(client);
+						continue ITERATE;
+					}
+					
+					try
+					{
+						final Queue<WritablePacket> packetQueue = client.getSendPacketQueue();
+						if (packetQueue.isEmpty())
+						{
+							continue ITERATE;
+						}
+						
+						final OutputStream outputStream = client.getOutputStream();
+						SEND_CYCLE: for (int count = 0; count < MAX_PACKETS_SENT_PER_CYCLE; count++)
+						{
+							final WritablePacket writablePacket = packetQueue.poll();
+							if (writablePacket == null)
+							{
+								continue ITERATE;
+							}
+							
+							final byte[] sendableBytes = writablePacket.getSendableBytes(client.getEncryption());
+							if (sendableBytes == null)
+							{
+								continue SEND_CYCLE;
+							}
+							
+							// Send the packet data.
+							outputStream.write(sendableBytes);
+							outputStream.flush();
+							
+							// Run packet implementation.
+							writablePacket.run();
+							
+							_idle = false;
+						}
+					}
+					catch (Exception ignored)
+					{
+					}
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+			else // Remain idle for 1 second.
+			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+		}
+	}
+}

L2J_Mobius_02.5_Underground/java/org/l2jmobius/commons/network/WritablePacket.java

@@ -223,6 +223,14 @@ public abstract class WritablePacket
 		// Overridden by server implementation.
 	}
 	
+	/**
+	 * Method that runs after packet is sent.
+	 */
+	public void run()
+	{
+		// Overridden by server implementation.
+	}
+	
 	/**
 	 * @return <b>byte[]</b> of the sendable packet data, including a size header.
 	 */

L2J_Mobius_02.5_Underground/java/org/l2jmobius/gameserver/GameServer.java

@@ -464,6 +464,7 @@ public class GameServer
 		final NetServer<GameClient> server = new NetServer<>(Config.GAMESERVER_HOSTNAME, Config.PORT_GAME, new PacketHandler(), GameClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(Config.CLIENT_READ_POOL_SIZE);
+		server.getNetConfig().setSendPoolSize(Config.CLIENT_SEND_POOL_SIZE);
 		server.getNetConfig().setExecutePoolSize(Config.CLIENT_EXECUTE_POOL_SIZE);
 		server.getNetConfig().setPacketQueueLimit(Config.PACKET_QUEUE_LIMIT);
 		server.getNetConfig().setPacketFloodDisconnect(Config.PACKET_FLOOD_DISCONNECT);

L2J_Mobius_02.5_Underground/java/org/l2jmobius/gameserver/network/GameClient.java

@@ -20,8 +20,6 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.util.List;
-import java.util.Queue;
-import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -66,7 +64,6 @@ public class GameClient extends NetClient
 {
 	protected static final Logger LOGGER_ACCOUNTING = Logger.getLogger("accounting");
 	
-	private final Queue<ServerPacket> _pendingPackets = new ConcurrentLinkedQueue<>();
 	private final FloodProtectors _floodProtectors = new FloodProtectors(this);
 	private final ReentrantLock _playerLock = new ReentrantLock();
 	private ConnectionState _connectionState = ConnectionState.CONNECTED;
@@ -218,16 +215,11 @@ public class GameClient extends NetClient
 			}
 		}
 		
-		// Keep the order of packets if sent by multiple threads.
+		// Used by packet run() method.
-		_pendingPackets.add(packet);
+		packet.setPlayer(_player);
-		synchronized (_pendingPackets)
+		
-		{
+		// Send the packet data.
-			// Send the packet data.
+		super.sendPacket(packet);
-			super.sendPacket(packet);
-			
-			// Run packet implementation.
-			packet.run(_player);
-		}
 	}
 	
 	public void sendPacket(SystemMessageId systemMessageId)

L2J_Mobius_02.5_Underground/java/org/l2jmobius/gameserver/network/serverpackets/AbstractHtmlPacket.java

@@ -131,12 +131,14 @@ public abstract class AbstractHtmlPacket extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.clearHtmlActions(getScope());
 		}
+		
 		if (_disabledValidation)
 		{
 			return;

L2J_Mobius_02.5_Underground/java/org/l2jmobius/gameserver/network/serverpackets/CreatureSay.java

@@ -162,8 +162,9 @@ public class CreatureSay extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.broadcastSnoop(_chatType, _senderName, _text);

L2J_Mobius_02.5_Underground/java/org/l2jmobius/gameserver/network/serverpackets/ServerPacket.java

@@ -112,12 +112,22 @@ public abstract class ServerPacket extends WritablePacket
 		super(initialSize);
 	}
 	
+	private Player _player;
+	
 	/**
-	 * Method that runs after packet is sent.
+	 * @return the Player
-	 * @param player
 	 */
-	public void run(Player player)
+	public Player getPlayer()
 	{
+		return _player;
+	}
+	
+	/**
+	 * @param player the Player to set.
+	 */
+	public void setPlayer(Player player)
+	{
+		_player = player;
 	}
 	
 	protected void writeOptionalInt(int value)

L2J_Mobius_02.5_Underground/java/org/l2jmobius/loginserver/LoginServer.java

@@ -136,6 +136,7 @@ public class LoginServer
 		final NetServer<LoginClient> server = new NetServer<>(Config.LOGIN_BIND_ADDRESS, Config.PORT_LOGIN, new LoginPacketHandler(), LoginClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(2000);
+		server.getNetConfig().setSendPoolSize(2000);
 		server.getNetConfig().setExecutePoolSize(2000);
 		server.getNetConfig().setPacketQueueLimit(10);
 		server.getNetConfig().setPacketFloodDisconnect(true);

L2J_Mobius_03.0_Helios/dist/game/config/Server.ini

@@ -36,6 +36,11 @@ GameserverPort = 7777
 # Default: 100
 ClientReadPoolSize = 100
 
+# Client pool size for sending server packets.
+# Each pool is executed on a separate thread.
+# Default: 25
+ClientSendPoolSize = 25
+
 # Client pool size for executing client packets.
 # Each pool is executed on a separate thread.
 # Default: 50

L2J_Mobius_03.0_Helios/java/org/l2jmobius/Config.java

@@ -780,6 +780,7 @@ public class Config
 	public static int LOGIN_BLOCK_AFTER_BAN;
 	public static String GAMESERVER_HOSTNAME;
 	public static int CLIENT_READ_POOL_SIZE;
+	public static int CLIENT_SEND_POOL_SIZE;
 	public static int CLIENT_EXECUTE_POOL_SIZE;
 	public static int PACKET_QUEUE_LIMIT;
 	public static boolean PACKET_FLOOD_DISCONNECT;
@@ -1387,6 +1388,7 @@ public class Config
 			GAME_SERVER_LOGIN_PORT = serverConfig.getInt("LoginPort", 9014);
 			GAME_SERVER_LOGIN_HOST = serverConfig.getString("LoginHost", "127.0.0.1");
 			CLIENT_READ_POOL_SIZE = serverConfig.getInt("ClientReadPoolSize", 100);
+			CLIENT_SEND_POOL_SIZE = serverConfig.getInt("ClientSendPoolSize", 25);
 			CLIENT_EXECUTE_POOL_SIZE = serverConfig.getInt("ClientExecutePoolSize", 50);
 			PACKET_QUEUE_LIMIT = serverConfig.getInt("PacketQueueLimit", 80);
 			PACKET_FLOOD_DISCONNECT = serverConfig.getBoolean("PacketFloodDisconnect", false);

L2J_Mobius_03.0_Helios/java/org/l2jmobius/commons/network/ExecuteThread.java

@@ -16,6 +16,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 	
 	private final Set<E> _pool;
 	private final PacketHandlerInterface<E> _packetHandler;
+	private boolean _idle;
 	
 	public ExecuteThread(Set<E> pool, PacketHandlerInterface<E> packetHandler)
 	{
@@ -31,6 +32,8 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -40,7 +43,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						continue ITERATE;
 					}
 					
-					final byte[] data = client.getPacketData().poll();
+					final byte[] data = client.getReceivedData().poll();
 					if (data == null)
 					{
 						continue ITERATE;
@@ -64,16 +67,29 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						}
 					}
 					_packetHandler.handle(client, new ReadablePacket(data));
+					
+					_idle = false;
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
 				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_03.0_Helios/java/org/l2jmobius/commons/network/NetClient.java

@@ -15,12 +15,15 @@ public class NetClient
 {
 	protected static final Logger LOGGER = Logger.getLogger(NetClient.class.getName());
 	
+	private final Queue<byte[]> _receivedData = new ConcurrentLinkedQueue<>();
+	private final Queue<WritablePacket> _sendPacketQueue = new ConcurrentLinkedQueue<>();
+	
 	private String _ip;
 	private Socket _socket;
 	private InputStream _inputStream;
 	private OutputStream _outputStream;
 	private NetConfig _netConfig;
-	private Queue<byte[]> _packetData;
+	
 	private byte[] _pendingData;
 	private int _pendingPacketSize;
 	
@@ -33,7 +36,6 @@ public class NetClient
 	{
 		_socket = socket;
 		_netConfig = netConfig;
-		_packetData = new ConcurrentLinkedQueue<>();
 		_ip = socket.getInetAddress().toString().substring(1); // Trim out /127.0.0.1
 		
 		try
@@ -82,10 +84,8 @@ public class NetClient
 			}
 		}
 		
-		if (_packetData != null)
+		_receivedData.clear();
-		{
+		_sendPacketQueue.clear();
-			_packetData.clear();
-		}
 		
 		if (_pendingData != null)
 		{
@@ -97,10 +97,10 @@ public class NetClient
 	 * Add packet data to the queue.
 	 * @param data
 	 */
-	public void addPacketData(byte[] data)
+	public void addReceivedData(byte[] data)
 	{
 		// Check packet flooding.
-		final int size = _packetData.size();
+		final int size = _receivedData.size();
 		if (size >= _netConfig.getPacketQueueLimit())
 		{
 			if (_netConfig.isPacketFloodDisconnect())
@@ -127,15 +127,15 @@ public class NetClient
 		}
 		
 		// Add to queue.
-		_packetData.add(data);
+		_receivedData.add(data);
 	}
 	
 	/**
-	 * @return the pending packet data.
+	 * @return the pending received data.
 	 */
-	public Queue<byte[]> getPacketData()
+	public Queue<byte[]> getReceivedData()
 	{
-		return _packetData;
+		return _receivedData;
 	}
 	
 	/**
@@ -172,34 +172,21 @@ public class NetClient
 		_pendingPacketSize = pendingPacketSize;
 	}
 	
+	/**
+	 * @return the writable packet queue waiting to be sent.
+	 */
+	public Queue<WritablePacket> getSendPacketQueue()
+	{
+		return _sendPacketQueue;
+	}
+	
 	/**
 	 * Sends a packet over the network using the default encryption.
 	 * @param packet The packet to send.
 	 */
 	public void sendPacket(WritablePacket packet)
 	{
-		if ((_socket == null) || !_socket.isConnected())
+		_sendPacketQueue.add(packet);
-		{
-			return;
-		}
-		
-		final byte[] sendableBytes = packet.getSendableBytes(getEncryption());
-		if (sendableBytes == null)
-		{
-			return;
-		}
-		
-		try
-		{
-			synchronized (this)
-			{
-				_outputStream.write(sendableBytes);
-				_outputStream.flush();
-			}
-		}
-		catch (Exception ignored)
-		{
-		}
 	}
 	
 	/**

L2J_Mobius_03.0_Helios/java/org/l2jmobius/commons/network/NetConfig.java

@@ -7,6 +7,7 @@ package org.l2jmobius.commons.network;
 public class NetConfig
 {
 	private int _readPoolSize = 100;
+	private int _sendPoolSize = 25;
 	private int _executePoolSize = 50;
 	private int _packetQueueLimit = 80;
 	private boolean _packetFloodDisconnect = false;
@@ -32,6 +33,23 @@ public class NetConfig
 		_readPoolSize = clientPoolSize;
 	}
 	
+	/**
+	 * @return the NetClient pool size for sending server packets.
+	 */
+	public int getSendPoolSize()
+	{
+		return _sendPoolSize;
+	}
+	
+	/**
+	 * Sets the NetClient pool size for sending server packets.
+	 * @param clientPoolSize
+	 */
+	public void setSendPoolSize(int clientPoolSize)
+	{
+		_sendPoolSize = clientPoolSize;
+	}
+	
 	/**
 	 * @return the NetClient pool size for executing client packets.
 	 */

L2J_Mobius_03.0_Helios/java/org/l2jmobius/commons/network/NetServer.java

@@ -20,6 +20,7 @@ public class NetServer<E extends NetClient>
 	protected static final Logger LOGGER = Logger.getLogger(NetServer.class.getName());
 	
 	protected final List<Set<E>> _clientReadPools = new LinkedList<>();
+	protected final List<Set<E>> _clientSendPools = new LinkedList<>();
 	protected final List<Set<E>> _clientExecutePools = new LinkedList<>();
 	protected final NetConfig _netConfig = new NetConfig();
 	protected final String _hostname;
@@ -155,6 +156,35 @@ public class NetServer<E extends NetClient>
 							_clientReadPools.add(newReadPool);
 						}
 						
+						// Add to send pool.
+						
+						// Find a pool that is not full.
+						boolean sendPoolFound = false;
+						SEND_POOLS: for (Set<E> pool : _clientSendPools)
+						{
+							if (pool.size() < _netConfig.getSendPoolSize())
+							{
+								pool.add(client);
+								sendPoolFound = true;
+								break SEND_POOLS;
+							}
+						}
+						
+						// All pools are full.
+						if (!sendPoolFound)
+						{
+							// Create a new client pool.
+							final Set<E> newSendPool = ConcurrentHashMap.newKeySet(_netConfig.getSendPoolSize());
+							newSendPool.add(client);
+							// Create a new task for the new pool.
+							final Thread sendThread = new Thread(new SendThread<>(newSendPool), _name + ": Packet send thread " + _clientSendPools.size());
+							sendThread.setPriority(Thread.MAX_PRIORITY);
+							sendThread.setDaemon(true);
+							sendThread.start();
+							// Add the new pool to the pool list.
+							_clientSendPools.add(newSendPool);
+						}
+						
 						// Add to execute pool.
 						
 						// Find a pool that is not full.

L2J_Mobius_03.0_Helios/java/org/l2jmobius/commons/network/ReadThread.java

@@ -14,6 +14,7 @@ public class ReadThread<E extends NetClient> implements Runnable
 	private final Set<E> _pool;
 	private final byte[] _sizeBuffer = new byte[2]; // Reusable size buffer.
 	private final byte[] _pendingSizeBuffer = new byte[1]; // Reusable pending size buffer.
+	private boolean _idle;
 	
 	public ReadThread(Set<E> pool)
 	{
@@ -28,6 +29,8 @@ public class ReadThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -80,14 +83,16 @@ public class ReadThread<E extends NetClient> implements Runnable
 									// Read was complete.
 									if (currentSize >= pendingPacketSize)
 									{
-										// Add packet data to client.
+										// Add received data to client.
-										client.addPacketData(mergedData);
+										client.addReceivedData(mergedData);
 										client.setPendingData(null);
 									}
 									else
 									{
 										client.setPendingData(mergedData);
 									}
+									
+									_idle = false;
 								}
 							}
 							continue ITERATE;
@@ -188,10 +193,12 @@ public class ReadThread<E extends NetClient> implements Runnable
 											client.setPendingData(pendindBytes);
 											client.setPendingPacketSize(packetSize);
 										}
-										else // Add packet data to client.
+										else // Add received data to client.
 										{
-											client.addPacketData(packetData);
+											client.addReceivedData(packetData);
 										}
+										
+										_idle = false;
 									}
 								}
 							}
@@ -206,15 +213,26 @@ public class ReadThread<E extends NetClient> implements Runnable
 						onDisconnection(client);
 					}
 				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_03.0_Helios/java/org/l2jmobius/commons/network/SendThread.java

@@ -0,0 +1,106 @@
+package org.l2jmobius.commons.network;
+
+import java.io.OutputStream;
+import java.net.Socket;
+import java.util.Queue;
+import java.util.Set;
+
+/**
+ * @author Pantelis Andrianakis
+ * @since June 22nd 2023
+ * @param <E> extends NetClient
+ */
+public class SendThread<E extends NetClient> implements Runnable
+{
+	// Throttle packets sent per cycle to limit flooding from waiting one client.
+	private static final int MAX_PACKETS_SENT_PER_CYCLE = 2000;
+	
+	private final Set<E> _pool;
+	private boolean _idle;
+	
+	public SendThread(Set<E> pool)
+	{
+		_pool = pool;
+	}
+	
+	@Override
+	public void run()
+	{
+		while (true)
+		{
+			// No need to iterate when pool is empty.
+			if (!_pool.isEmpty())
+			{
+				_idle = true;
+				
+				// Iterate client pool.
+				ITERATE: for (E client : _pool)
+				{
+					final Socket socket = client.getSocket();
+					if (socket == null)
+					{
+						_pool.remove(client);
+						continue ITERATE;
+					}
+					
+					try
+					{
+						final Queue<WritablePacket> packetQueue = client.getSendPacketQueue();
+						if (packetQueue.isEmpty())
+						{
+							continue ITERATE;
+						}
+						
+						final OutputStream outputStream = client.getOutputStream();
+						SEND_CYCLE: for (int count = 0; count < MAX_PACKETS_SENT_PER_CYCLE; count++)
+						{
+							final WritablePacket writablePacket = packetQueue.poll();
+							if (writablePacket == null)
+							{
+								continue ITERATE;
+							}
+							
+							final byte[] sendableBytes = writablePacket.getSendableBytes(client.getEncryption());
+							if (sendableBytes == null)
+							{
+								continue SEND_CYCLE;
+							}
+							
+							// Send the packet data.
+							outputStream.write(sendableBytes);
+							outputStream.flush();
+							
+							// Run packet implementation.
+							writablePacket.run();
+							
+							_idle = false;
+						}
+					}
+					catch (Exception ignored)
+					{
+					}
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+			else // Remain idle for 1 second.
+			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+		}
+	}
+}

L2J_Mobius_03.0_Helios/java/org/l2jmobius/commons/network/WritablePacket.java

@@ -223,6 +223,14 @@ public abstract class WritablePacket
 		// Overridden by server implementation.
 	}
 	
+	/**
+	 * Method that runs after packet is sent.
+	 */
+	public void run()
+	{
+		// Overridden by server implementation.
+	}
+	
 	/**
 	 * @return <b>byte[]</b> of the sendable packet data, including a size header.
 	 */

L2J_Mobius_03.0_Helios/java/org/l2jmobius/gameserver/GameServer.java

@@ -464,6 +464,7 @@ public class GameServer
 		final NetServer<GameClient> server = new NetServer<>(Config.GAMESERVER_HOSTNAME, Config.PORT_GAME, new PacketHandler(), GameClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(Config.CLIENT_READ_POOL_SIZE);
+		server.getNetConfig().setSendPoolSize(Config.CLIENT_SEND_POOL_SIZE);
 		server.getNetConfig().setExecutePoolSize(Config.CLIENT_EXECUTE_POOL_SIZE);
 		server.getNetConfig().setPacketQueueLimit(Config.PACKET_QUEUE_LIMIT);
 		server.getNetConfig().setPacketFloodDisconnect(Config.PACKET_FLOOD_DISCONNECT);

L2J_Mobius_03.0_Helios/java/org/l2jmobius/gameserver/network/GameClient.java

@@ -20,8 +20,6 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.util.List;
-import java.util.Queue;
-import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -66,7 +64,6 @@ public class GameClient extends NetClient
 {
 	protected static final Logger LOGGER_ACCOUNTING = Logger.getLogger("accounting");
 	
-	private final Queue<ServerPacket> _pendingPackets = new ConcurrentLinkedQueue<>();
 	private final FloodProtectors _floodProtectors = new FloodProtectors(this);
 	private final ReentrantLock _playerLock = new ReentrantLock();
 	private ConnectionState _connectionState = ConnectionState.CONNECTED;
@@ -218,16 +215,11 @@ public class GameClient extends NetClient
 			}
 		}
 		
-		// Keep the order of packets if sent by multiple threads.
+		// Used by packet run() method.
-		_pendingPackets.add(packet);
+		packet.setPlayer(_player);
-		synchronized (_pendingPackets)
+		
-		{
+		// Send the packet data.
-			// Send the packet data.
+		super.sendPacket(packet);
-			super.sendPacket(packet);
-			
-			// Run packet implementation.
-			packet.run(_player);
-		}
 	}
 	
 	public void sendPacket(SystemMessageId systemMessageId)

L2J_Mobius_03.0_Helios/java/org/l2jmobius/gameserver/network/serverpackets/AbstractHtmlPacket.java

@@ -131,12 +131,14 @@ public abstract class AbstractHtmlPacket extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.clearHtmlActions(getScope());
 		}
+		
 		if (_disabledValidation)
 		{
 			return;

L2J_Mobius_03.0_Helios/java/org/l2jmobius/gameserver/network/serverpackets/CreatureSay.java

@@ -162,8 +162,9 @@ public class CreatureSay extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.broadcastSnoop(_chatType, _senderName, _text);

L2J_Mobius_03.0_Helios/java/org/l2jmobius/gameserver/network/serverpackets/ServerPacket.java

@@ -112,12 +112,22 @@ public abstract class ServerPacket extends WritablePacket
 		super(initialSize);
 	}
 	
+	private Player _player;
+	
 	/**
-	 * Method that runs after packet is sent.
+	 * @return the Player
-	 * @param player
 	 */
-	public void run(Player player)
+	public Player getPlayer()
 	{
+		return _player;
+	}
+	
+	/**
+	 * @param player the Player to set.
+	 */
+	public void setPlayer(Player player)
+	{
+		_player = player;
 	}
 	
 	protected void writeOptionalInt(int value)

L2J_Mobius_03.0_Helios/java/org/l2jmobius/loginserver/LoginServer.java

@@ -136,6 +136,7 @@ public class LoginServer
 		final NetServer<LoginClient> server = new NetServer<>(Config.LOGIN_BIND_ADDRESS, Config.PORT_LOGIN, new LoginPacketHandler(), LoginClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(2000);
+		server.getNetConfig().setSendPoolSize(2000);
 		server.getNetConfig().setExecutePoolSize(2000);
 		server.getNetConfig().setPacketQueueLimit(10);
 		server.getNetConfig().setPacketFloodDisconnect(true);

L2J_Mobius_04.0_GrandCrusade/dist/game/config/Server.ini

@@ -36,6 +36,11 @@ GameserverPort = 7777
 # Default: 100
 ClientReadPoolSize = 100
 
+# Client pool size for sending server packets.
+# Each pool is executed on a separate thread.
+# Default: 25
+ClientSendPoolSize = 25
+
 # Client pool size for executing client packets.
 # Each pool is executed on a separate thread.
 # Default: 50

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/Config.java

@@ -767,6 +767,7 @@ public class Config
 	public static int LOGIN_BLOCK_AFTER_BAN;
 	public static String GAMESERVER_HOSTNAME;
 	public static int CLIENT_READ_POOL_SIZE;
+	public static int CLIENT_SEND_POOL_SIZE;
 	public static int CLIENT_EXECUTE_POOL_SIZE;
 	public static int PACKET_QUEUE_LIMIT;
 	public static boolean PACKET_FLOOD_DISCONNECT;
@@ -1374,6 +1375,7 @@ public class Config
 			GAME_SERVER_LOGIN_PORT = serverConfig.getInt("LoginPort", 9014);
 			GAME_SERVER_LOGIN_HOST = serverConfig.getString("LoginHost", "127.0.0.1");
 			CLIENT_READ_POOL_SIZE = serverConfig.getInt("ClientReadPoolSize", 100);
+			CLIENT_SEND_POOL_SIZE = serverConfig.getInt("ClientSendPoolSize", 25);
 			CLIENT_EXECUTE_POOL_SIZE = serverConfig.getInt("ClientExecutePoolSize", 50);
 			PACKET_QUEUE_LIMIT = serverConfig.getInt("PacketQueueLimit", 80);
 			PACKET_FLOOD_DISCONNECT = serverConfig.getBoolean("PacketFloodDisconnect", false);

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/commons/network/ExecuteThread.java

@@ -16,6 +16,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 	
 	private final Set<E> _pool;
 	private final PacketHandlerInterface<E> _packetHandler;
+	private boolean _idle;
 	
 	public ExecuteThread(Set<E> pool, PacketHandlerInterface<E> packetHandler)
 	{
@@ -31,6 +32,8 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -40,7 +43,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						continue ITERATE;
 					}
 					
-					final byte[] data = client.getPacketData().poll();
+					final byte[] data = client.getReceivedData().poll();
 					if (data == null)
 					{
 						continue ITERATE;
@@ -64,16 +67,29 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						}
 					}
 					_packetHandler.handle(client, new ReadablePacket(data));
+					
+					_idle = false;
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
 				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/commons/network/NetClient.java

@@ -15,12 +15,15 @@ public class NetClient
 {
 	protected static final Logger LOGGER = Logger.getLogger(NetClient.class.getName());
 	
+	private final Queue<byte[]> _receivedData = new ConcurrentLinkedQueue<>();
+	private final Queue<WritablePacket> _sendPacketQueue = new ConcurrentLinkedQueue<>();
+	
 	private String _ip;
 	private Socket _socket;
 	private InputStream _inputStream;
 	private OutputStream _outputStream;
 	private NetConfig _netConfig;
-	private Queue<byte[]> _packetData;
+	
 	private byte[] _pendingData;
 	private int _pendingPacketSize;
 	
@@ -33,7 +36,6 @@ public class NetClient
 	{
 		_socket = socket;
 		_netConfig = netConfig;
-		_packetData = new ConcurrentLinkedQueue<>();
 		_ip = socket.getInetAddress().toString().substring(1); // Trim out /127.0.0.1
 		
 		try
@@ -82,10 +84,8 @@ public class NetClient
 			}
 		}
 		
-		if (_packetData != null)
+		_receivedData.clear();
-		{
+		_sendPacketQueue.clear();
-			_packetData.clear();
-		}
 		
 		if (_pendingData != null)
 		{
@@ -97,10 +97,10 @@ public class NetClient
 	 * Add packet data to the queue.
 	 * @param data
 	 */
-	public void addPacketData(byte[] data)
+	public void addReceivedData(byte[] data)
 	{
 		// Check packet flooding.
-		final int size = _packetData.size();
+		final int size = _receivedData.size();
 		if (size >= _netConfig.getPacketQueueLimit())
 		{
 			if (_netConfig.isPacketFloodDisconnect())
@@ -127,15 +127,15 @@ public class NetClient
 		}
 		
 		// Add to queue.
-		_packetData.add(data);
+		_receivedData.add(data);
 	}
 	
 	/**
-	 * @return the pending packet data.
+	 * @return the pending received data.
 	 */
-	public Queue<byte[]> getPacketData()
+	public Queue<byte[]> getReceivedData()
 	{
-		return _packetData;
+		return _receivedData;
 	}
 	
 	/**
@@ -172,34 +172,21 @@ public class NetClient
 		_pendingPacketSize = pendingPacketSize;
 	}
 	
+	/**
+	 * @return the writable packet queue waiting to be sent.
+	 */
+	public Queue<WritablePacket> getSendPacketQueue()
+	{
+		return _sendPacketQueue;
+	}
+	
 	/**
 	 * Sends a packet over the network using the default encryption.
 	 * @param packet The packet to send.
 	 */
 	public void sendPacket(WritablePacket packet)
 	{
-		if ((_socket == null) || !_socket.isConnected())
+		_sendPacketQueue.add(packet);
-		{
-			return;
-		}
-		
-		final byte[] sendableBytes = packet.getSendableBytes(getEncryption());
-		if (sendableBytes == null)
-		{
-			return;
-		}
-		
-		try
-		{
-			synchronized (this)
-			{
-				_outputStream.write(sendableBytes);
-				_outputStream.flush();
-			}
-		}
-		catch (Exception ignored)
-		{
-		}
 	}
 	
 	/**

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/commons/network/NetConfig.java

@@ -7,6 +7,7 @@ package org.l2jmobius.commons.network;
 public class NetConfig
 {
 	private int _readPoolSize = 100;
+	private int _sendPoolSize = 25;
 	private int _executePoolSize = 50;
 	private int _packetQueueLimit = 80;
 	private boolean _packetFloodDisconnect = false;
@@ -32,6 +33,23 @@ public class NetConfig
 		_readPoolSize = clientPoolSize;
 	}
 	
+	/**
+	 * @return the NetClient pool size for sending server packets.
+	 */
+	public int getSendPoolSize()
+	{
+		return _sendPoolSize;
+	}
+	
+	/**
+	 * Sets the NetClient pool size for sending server packets.
+	 * @param clientPoolSize
+	 */
+	public void setSendPoolSize(int clientPoolSize)
+	{
+		_sendPoolSize = clientPoolSize;
+	}
+	
 	/**
 	 * @return the NetClient pool size for executing client packets.
 	 */

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/commons/network/NetServer.java

@@ -20,6 +20,7 @@ public class NetServer<E extends NetClient>
 	protected static final Logger LOGGER = Logger.getLogger(NetServer.class.getName());
 	
 	protected final List<Set<E>> _clientReadPools = new LinkedList<>();
+	protected final List<Set<E>> _clientSendPools = new LinkedList<>();
 	protected final List<Set<E>> _clientExecutePools = new LinkedList<>();
 	protected final NetConfig _netConfig = new NetConfig();
 	protected final String _hostname;
@@ -155,6 +156,35 @@ public class NetServer<E extends NetClient>
 							_clientReadPools.add(newReadPool);
 						}
 						
+						// Add to send pool.
+						
+						// Find a pool that is not full.
+						boolean sendPoolFound = false;
+						SEND_POOLS: for (Set<E> pool : _clientSendPools)
+						{
+							if (pool.size() < _netConfig.getSendPoolSize())
+							{
+								pool.add(client);
+								sendPoolFound = true;
+								break SEND_POOLS;
+							}
+						}
+						
+						// All pools are full.
+						if (!sendPoolFound)
+						{
+							// Create a new client pool.
+							final Set<E> newSendPool = ConcurrentHashMap.newKeySet(_netConfig.getSendPoolSize());
+							newSendPool.add(client);
+							// Create a new task for the new pool.
+							final Thread sendThread = new Thread(new SendThread<>(newSendPool), _name + ": Packet send thread " + _clientSendPools.size());
+							sendThread.setPriority(Thread.MAX_PRIORITY);
+							sendThread.setDaemon(true);
+							sendThread.start();
+							// Add the new pool to the pool list.
+							_clientSendPools.add(newSendPool);
+						}
+						
 						// Add to execute pool.
 						
 						// Find a pool that is not full.

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/commons/network/ReadThread.java

@@ -14,6 +14,7 @@ public class ReadThread<E extends NetClient> implements Runnable
 	private final Set<E> _pool;
 	private final byte[] _sizeBuffer = new byte[2]; // Reusable size buffer.
 	private final byte[] _pendingSizeBuffer = new byte[1]; // Reusable pending size buffer.
+	private boolean _idle;
 	
 	public ReadThread(Set<E> pool)
 	{
@@ -28,6 +29,8 @@ public class ReadThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -80,14 +83,16 @@ public class ReadThread<E extends NetClient> implements Runnable
 									// Read was complete.
 									if (currentSize >= pendingPacketSize)
 									{
-										// Add packet data to client.
+										// Add received data to client.
-										client.addPacketData(mergedData);
+										client.addReceivedData(mergedData);
 										client.setPendingData(null);
 									}
 									else
 									{
 										client.setPendingData(mergedData);
 									}
+									
+									_idle = false;
 								}
 							}
 							continue ITERATE;
@@ -188,10 +193,12 @@ public class ReadThread<E extends NetClient> implements Runnable
 											client.setPendingData(pendindBytes);
 											client.setPendingPacketSize(packetSize);
 										}
-										else // Add packet data to client.
+										else // Add received data to client.
 										{
-											client.addPacketData(packetData);
+											client.addReceivedData(packetData);
 										}
+										
+										_idle = false;
 									}
 								}
 							}
@@ -206,15 +213,26 @@ public class ReadThread<E extends NetClient> implements Runnable
 						onDisconnection(client);
 					}
 				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/commons/network/SendThread.java

@@ -0,0 +1,106 @@
+package org.l2jmobius.commons.network;
+
+import java.io.OutputStream;
+import java.net.Socket;
+import java.util.Queue;
+import java.util.Set;
+
+/**
+ * @author Pantelis Andrianakis
+ * @since June 22nd 2023
+ * @param <E> extends NetClient
+ */
+public class SendThread<E extends NetClient> implements Runnable
+{
+	// Throttle packets sent per cycle to limit flooding from waiting one client.
+	private static final int MAX_PACKETS_SENT_PER_CYCLE = 2000;
+	
+	private final Set<E> _pool;
+	private boolean _idle;
+	
+	public SendThread(Set<E> pool)
+	{
+		_pool = pool;
+	}
+	
+	@Override
+	public void run()
+	{
+		while (true)
+		{
+			// No need to iterate when pool is empty.
+			if (!_pool.isEmpty())
+			{
+				_idle = true;
+				
+				// Iterate client pool.
+				ITERATE: for (E client : _pool)
+				{
+					final Socket socket = client.getSocket();
+					if (socket == null)
+					{
+						_pool.remove(client);
+						continue ITERATE;
+					}
+					
+					try
+					{
+						final Queue<WritablePacket> packetQueue = client.getSendPacketQueue();
+						if (packetQueue.isEmpty())
+						{
+							continue ITERATE;
+						}
+						
+						final OutputStream outputStream = client.getOutputStream();
+						SEND_CYCLE: for (int count = 0; count < MAX_PACKETS_SENT_PER_CYCLE; count++)
+						{
+							final WritablePacket writablePacket = packetQueue.poll();
+							if (writablePacket == null)
+							{
+								continue ITERATE;
+							}
+							
+							final byte[] sendableBytes = writablePacket.getSendableBytes(client.getEncryption());
+							if (sendableBytes == null)
+							{
+								continue SEND_CYCLE;
+							}
+							
+							// Send the packet data.
+							outputStream.write(sendableBytes);
+							outputStream.flush();
+							
+							// Run packet implementation.
+							writablePacket.run();
+							
+							_idle = false;
+						}
+					}
+					catch (Exception ignored)
+					{
+					}
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+			else // Remain idle for 1 second.
+			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+		}
+	}
+}

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/commons/network/WritablePacket.java

@@ -223,6 +223,14 @@ public abstract class WritablePacket
 		// Overridden by server implementation.
 	}
 	
+	/**
+	 * Method that runs after packet is sent.
+	 */
+	public void run()
+	{
+		// Overridden by server implementation.
+	}
+	
 	/**
 	 * @return <b>byte[]</b> of the sendable packet data, including a size header.
 	 */

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/gameserver/GameServer.java

@@ -464,6 +464,7 @@ public class GameServer
 		final NetServer<GameClient> server = new NetServer<>(Config.GAMESERVER_HOSTNAME, Config.PORT_GAME, new PacketHandler(), GameClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(Config.CLIENT_READ_POOL_SIZE);
+		server.getNetConfig().setSendPoolSize(Config.CLIENT_SEND_POOL_SIZE);
 		server.getNetConfig().setExecutePoolSize(Config.CLIENT_EXECUTE_POOL_SIZE);
 		server.getNetConfig().setPacketQueueLimit(Config.PACKET_QUEUE_LIMIT);
 		server.getNetConfig().setPacketFloodDisconnect(Config.PACKET_FLOOD_DISCONNECT);

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/gameserver/network/GameClient.java

@@ -20,8 +20,6 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.util.List;
-import java.util.Queue;
-import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -66,7 +64,6 @@ public class GameClient extends NetClient
 {
 	protected static final Logger LOGGER_ACCOUNTING = Logger.getLogger("accounting");
 	
-	private final Queue<ServerPacket> _pendingPackets = new ConcurrentLinkedQueue<>();
 	private final FloodProtectors _floodProtectors = new FloodProtectors(this);
 	private final ReentrantLock _playerLock = new ReentrantLock();
 	private ConnectionState _connectionState = ConnectionState.CONNECTED;
@@ -218,16 +215,11 @@ public class GameClient extends NetClient
 			}
 		}
 		
-		// Keep the order of packets if sent by multiple threads.
+		// Used by packet run() method.
-		_pendingPackets.add(packet);
+		packet.setPlayer(_player);
-		synchronized (_pendingPackets)
+		
-		{
+		// Send the packet data.
-			// Send the packet data.
+		super.sendPacket(packet);
-			super.sendPacket(packet);
-			
-			// Run packet implementation.
-			packet.run(_player);
-		}
 	}
 	
 	public void sendPacket(SystemMessageId systemMessageId)

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/gameserver/network/serverpackets/AbstractHtmlPacket.java

@@ -131,12 +131,14 @@ public abstract class AbstractHtmlPacket extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.clearHtmlActions(getScope());
 		}
+		
 		if (_disabledValidation)
 		{
 			return;

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/gameserver/network/serverpackets/CreatureSay.java

@@ -162,8 +162,9 @@ public class CreatureSay extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.broadcastSnoop(_chatType, _senderName, _text);

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/gameserver/network/serverpackets/ServerPacket.java

@@ -112,12 +112,22 @@ public abstract class ServerPacket extends WritablePacket
 		super(initialSize);
 	}
 	
+	private Player _player;
+	
 	/**
-	 * Method that runs after packet is sent.
+	 * @return the Player
-	 * @param player
 	 */
-	public void run(Player player)
+	public Player getPlayer()
 	{
+		return _player;
+	}
+	
+	/**
+	 * @param player the Player to set.
+	 */
+	public void setPlayer(Player player)
+	{
+		_player = player;
 	}
 	
 	protected void writeOptionalInt(int value)

L2J_Mobius_04.0_GrandCrusade/java/org/l2jmobius/loginserver/LoginServer.java

@@ -136,6 +136,7 @@ public class LoginServer
 		final NetServer<LoginClient> server = new NetServer<>(Config.LOGIN_BIND_ADDRESS, Config.PORT_LOGIN, new LoginPacketHandler(), LoginClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(2000);
+		server.getNetConfig().setSendPoolSize(2000);
 		server.getNetConfig().setExecutePoolSize(2000);
 		server.getNetConfig().setPacketQueueLimit(10);
 		server.getNetConfig().setPacketFloodDisconnect(true);

L2J_Mobius_05.0_Salvation/dist/game/config/Server.ini

@@ -36,6 +36,11 @@ GameserverPort = 7777
 # Default: 100
 ClientReadPoolSize = 100
 
+# Client pool size for sending server packets.
+# Each pool is executed on a separate thread.
+# Default: 25
+ClientSendPoolSize = 25
+
 # Client pool size for executing client packets.
 # Each pool is executed on a separate thread.
 # Default: 50

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/Config.java

@@ -766,6 +766,7 @@ public class Config
 	public static int LOGIN_BLOCK_AFTER_BAN;
 	public static String GAMESERVER_HOSTNAME;
 	public static int CLIENT_READ_POOL_SIZE;
+	public static int CLIENT_SEND_POOL_SIZE;
 	public static int CLIENT_EXECUTE_POOL_SIZE;
 	public static int PACKET_QUEUE_LIMIT;
 	public static boolean PACKET_FLOOD_DISCONNECT;
@@ -1373,6 +1374,7 @@ public class Config
 			GAME_SERVER_LOGIN_PORT = serverConfig.getInt("LoginPort", 9014);
 			GAME_SERVER_LOGIN_HOST = serverConfig.getString("LoginHost", "127.0.0.1");
 			CLIENT_READ_POOL_SIZE = serverConfig.getInt("ClientReadPoolSize", 100);
+			CLIENT_SEND_POOL_SIZE = serverConfig.getInt("ClientSendPoolSize", 25);
 			CLIENT_EXECUTE_POOL_SIZE = serverConfig.getInt("ClientExecutePoolSize", 50);
 			PACKET_QUEUE_LIMIT = serverConfig.getInt("PacketQueueLimit", 80);
 			PACKET_FLOOD_DISCONNECT = serverConfig.getBoolean("PacketFloodDisconnect", false);

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/commons/network/ExecuteThread.java

@@ -16,6 +16,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 	
 	private final Set<E> _pool;
 	private final PacketHandlerInterface<E> _packetHandler;
+	private boolean _idle;
 	
 	public ExecuteThread(Set<E> pool, PacketHandlerInterface<E> packetHandler)
 	{
@@ -31,6 +32,8 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -40,7 +43,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						continue ITERATE;
 					}
 					
-					final byte[] data = client.getPacketData().poll();
+					final byte[] data = client.getReceivedData().poll();
 					if (data == null)
 					{
 						continue ITERATE;
@@ -64,16 +67,29 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						}
 					}
 					_packetHandler.handle(client, new ReadablePacket(data));
+					
+					_idle = false;
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
 				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/commons/network/NetClient.java

@@ -15,12 +15,15 @@ public class NetClient
 {
 	protected static final Logger LOGGER = Logger.getLogger(NetClient.class.getName());
 	
+	private final Queue<byte[]> _receivedData = new ConcurrentLinkedQueue<>();
+	private final Queue<WritablePacket> _sendPacketQueue = new ConcurrentLinkedQueue<>();
+	
 	private String _ip;
 	private Socket _socket;
 	private InputStream _inputStream;
 	private OutputStream _outputStream;
 	private NetConfig _netConfig;
-	private Queue<byte[]> _packetData;
+	
 	private byte[] _pendingData;
 	private int _pendingPacketSize;
 	
@@ -33,7 +36,6 @@ public class NetClient
 	{
 		_socket = socket;
 		_netConfig = netConfig;
-		_packetData = new ConcurrentLinkedQueue<>();
 		_ip = socket.getInetAddress().toString().substring(1); // Trim out /127.0.0.1
 		
 		try
@@ -82,10 +84,8 @@ public class NetClient
 			}
 		}
 		
-		if (_packetData != null)
+		_receivedData.clear();
-		{
+		_sendPacketQueue.clear();
-			_packetData.clear();
-		}
 		
 		if (_pendingData != null)
 		{
@@ -97,10 +97,10 @@ public class NetClient
 	 * Add packet data to the queue.
 	 * @param data
 	 */
-	public void addPacketData(byte[] data)
+	public void addReceivedData(byte[] data)
 	{
 		// Check packet flooding.
-		final int size = _packetData.size();
+		final int size = _receivedData.size();
 		if (size >= _netConfig.getPacketQueueLimit())
 		{
 			if (_netConfig.isPacketFloodDisconnect())
@@ -127,15 +127,15 @@ public class NetClient
 		}
 		
 		// Add to queue.
-		_packetData.add(data);
+		_receivedData.add(data);
 	}
 	
 	/**
-	 * @return the pending packet data.
+	 * @return the pending received data.
 	 */
-	public Queue<byte[]> getPacketData()
+	public Queue<byte[]> getReceivedData()
 	{
-		return _packetData;
+		return _receivedData;
 	}
 	
 	/**
@@ -172,34 +172,21 @@ public class NetClient
 		_pendingPacketSize = pendingPacketSize;
 	}
 	
+	/**
+	 * @return the writable packet queue waiting to be sent.
+	 */
+	public Queue<WritablePacket> getSendPacketQueue()
+	{
+		return _sendPacketQueue;
+	}
+	
 	/**
 	 * Sends a packet over the network using the default encryption.
 	 * @param packet The packet to send.
 	 */
 	public void sendPacket(WritablePacket packet)
 	{
-		if ((_socket == null) || !_socket.isConnected())
+		_sendPacketQueue.add(packet);
-		{
-			return;
-		}
-		
-		final byte[] sendableBytes = packet.getSendableBytes(getEncryption());
-		if (sendableBytes == null)
-		{
-			return;
-		}
-		
-		try
-		{
-			synchronized (this)
-			{
-				_outputStream.write(sendableBytes);
-				_outputStream.flush();
-			}
-		}
-		catch (Exception ignored)
-		{
-		}
 	}
 	
 	/**

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/commons/network/NetConfig.java

@@ -7,6 +7,7 @@ package org.l2jmobius.commons.network;
 public class NetConfig
 {
 	private int _readPoolSize = 100;
+	private int _sendPoolSize = 25;
 	private int _executePoolSize = 50;
 	private int _packetQueueLimit = 80;
 	private boolean _packetFloodDisconnect = false;
@@ -32,6 +33,23 @@ public class NetConfig
 		_readPoolSize = clientPoolSize;
 	}
 	
+	/**
+	 * @return the NetClient pool size for sending server packets.
+	 */
+	public int getSendPoolSize()
+	{
+		return _sendPoolSize;
+	}
+	
+	/**
+	 * Sets the NetClient pool size for sending server packets.
+	 * @param clientPoolSize
+	 */
+	public void setSendPoolSize(int clientPoolSize)
+	{
+		_sendPoolSize = clientPoolSize;
+	}
+	
 	/**
 	 * @return the NetClient pool size for executing client packets.
 	 */

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/commons/network/NetServer.java

@@ -20,6 +20,7 @@ public class NetServer<E extends NetClient>
 	protected static final Logger LOGGER = Logger.getLogger(NetServer.class.getName());
 	
 	protected final List<Set<E>> _clientReadPools = new LinkedList<>();
+	protected final List<Set<E>> _clientSendPools = new LinkedList<>();
 	protected final List<Set<E>> _clientExecutePools = new LinkedList<>();
 	protected final NetConfig _netConfig = new NetConfig();
 	protected final String _hostname;
@@ -155,6 +156,35 @@ public class NetServer<E extends NetClient>
 							_clientReadPools.add(newReadPool);
 						}
 						
+						// Add to send pool.
+						
+						// Find a pool that is not full.
+						boolean sendPoolFound = false;
+						SEND_POOLS: for (Set<E> pool : _clientSendPools)
+						{
+							if (pool.size() < _netConfig.getSendPoolSize())
+							{
+								pool.add(client);
+								sendPoolFound = true;
+								break SEND_POOLS;
+							}
+						}
+						
+						// All pools are full.
+						if (!sendPoolFound)
+						{
+							// Create a new client pool.
+							final Set<E> newSendPool = ConcurrentHashMap.newKeySet(_netConfig.getSendPoolSize());
+							newSendPool.add(client);
+							// Create a new task for the new pool.
+							final Thread sendThread = new Thread(new SendThread<>(newSendPool), _name + ": Packet send thread " + _clientSendPools.size());
+							sendThread.setPriority(Thread.MAX_PRIORITY);
+							sendThread.setDaemon(true);
+							sendThread.start();
+							// Add the new pool to the pool list.
+							_clientSendPools.add(newSendPool);
+						}
+						
 						// Add to execute pool.
 						
 						// Find a pool that is not full.

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/commons/network/ReadThread.java

@@ -14,6 +14,7 @@ public class ReadThread<E extends NetClient> implements Runnable
 	private final Set<E> _pool;
 	private final byte[] _sizeBuffer = new byte[2]; // Reusable size buffer.
 	private final byte[] _pendingSizeBuffer = new byte[1]; // Reusable pending size buffer.
+	private boolean _idle;
 	
 	public ReadThread(Set<E> pool)
 	{
@@ -28,6 +29,8 @@ public class ReadThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -80,14 +83,16 @@ public class ReadThread<E extends NetClient> implements Runnable
 									// Read was complete.
 									if (currentSize >= pendingPacketSize)
 									{
-										// Add packet data to client.
+										// Add received data to client.
-										client.addPacketData(mergedData);
+										client.addReceivedData(mergedData);
 										client.setPendingData(null);
 									}
 									else
 									{
 										client.setPendingData(mergedData);
 									}
+									
+									_idle = false;
 								}
 							}
 							continue ITERATE;
@@ -188,10 +193,12 @@ public class ReadThread<E extends NetClient> implements Runnable
 											client.setPendingData(pendindBytes);
 											client.setPendingPacketSize(packetSize);
 										}
-										else // Add packet data to client.
+										else // Add received data to client.
 										{
-											client.addPacketData(packetData);
+											client.addReceivedData(packetData);
 										}
+										
+										_idle = false;
 									}
 								}
 							}
@@ -206,15 +213,26 @@ public class ReadThread<E extends NetClient> implements Runnable
 						onDisconnection(client);
 					}
 				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/commons/network/SendThread.java

@@ -0,0 +1,106 @@
+package org.l2jmobius.commons.network;
+
+import java.io.OutputStream;
+import java.net.Socket;
+import java.util.Queue;
+import java.util.Set;
+
+/**
+ * @author Pantelis Andrianakis
+ * @since June 22nd 2023
+ * @param <E> extends NetClient
+ */
+public class SendThread<E extends NetClient> implements Runnable
+{
+	// Throttle packets sent per cycle to limit flooding from waiting one client.
+	private static final int MAX_PACKETS_SENT_PER_CYCLE = 2000;
+	
+	private final Set<E> _pool;
+	private boolean _idle;
+	
+	public SendThread(Set<E> pool)
+	{
+		_pool = pool;
+	}
+	
+	@Override
+	public void run()
+	{
+		while (true)
+		{
+			// No need to iterate when pool is empty.
+			if (!_pool.isEmpty())
+			{
+				_idle = true;
+				
+				// Iterate client pool.
+				ITERATE: for (E client : _pool)
+				{
+					final Socket socket = client.getSocket();
+					if (socket == null)
+					{
+						_pool.remove(client);
+						continue ITERATE;
+					}
+					
+					try
+					{
+						final Queue<WritablePacket> packetQueue = client.getSendPacketQueue();
+						if (packetQueue.isEmpty())
+						{
+							continue ITERATE;
+						}
+						
+						final OutputStream outputStream = client.getOutputStream();
+						SEND_CYCLE: for (int count = 0; count < MAX_PACKETS_SENT_PER_CYCLE; count++)
+						{
+							final WritablePacket writablePacket = packetQueue.poll();
+							if (writablePacket == null)
+							{
+								continue ITERATE;
+							}
+							
+							final byte[] sendableBytes = writablePacket.getSendableBytes(client.getEncryption());
+							if (sendableBytes == null)
+							{
+								continue SEND_CYCLE;
+							}
+							
+							// Send the packet data.
+							outputStream.write(sendableBytes);
+							outputStream.flush();
+							
+							// Run packet implementation.
+							writablePacket.run();
+							
+							_idle = false;
+						}
+					}
+					catch (Exception ignored)
+					{
+					}
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+			else // Remain idle for 1 second.
+			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+		}
+	}
+}

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/commons/network/WritablePacket.java

@@ -223,6 +223,14 @@ public abstract class WritablePacket
 		// Overridden by server implementation.
 	}
 	
+	/**
+	 * Method that runs after packet is sent.
+	 */
+	public void run()
+	{
+		// Overridden by server implementation.
+	}
+	
 	/**
 	 * @return <b>byte[]</b> of the sendable packet data, including a size header.
 	 */

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/gameserver/GameServer.java

@@ -468,6 +468,7 @@ public class GameServer
 		final NetServer<GameClient> server = new NetServer<>(Config.GAMESERVER_HOSTNAME, Config.PORT_GAME, new PacketHandler(), GameClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(Config.CLIENT_READ_POOL_SIZE);
+		server.getNetConfig().setSendPoolSize(Config.CLIENT_SEND_POOL_SIZE);
 		server.getNetConfig().setExecutePoolSize(Config.CLIENT_EXECUTE_POOL_SIZE);
 		server.getNetConfig().setPacketQueueLimit(Config.PACKET_QUEUE_LIMIT);
 		server.getNetConfig().setPacketFloodDisconnect(Config.PACKET_FLOOD_DISCONNECT);

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/gameserver/network/GameClient.java

@@ -20,8 +20,6 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.util.List;
-import java.util.Queue;
-import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -66,7 +64,6 @@ public class GameClient extends NetClient
 {
 	protected static final Logger LOGGER_ACCOUNTING = Logger.getLogger("accounting");
 	
-	private final Queue<ServerPacket> _pendingPackets = new ConcurrentLinkedQueue<>();
 	private final FloodProtectors _floodProtectors = new FloodProtectors(this);
 	private final ReentrantLock _playerLock = new ReentrantLock();
 	private ConnectionState _connectionState = ConnectionState.CONNECTED;
@@ -218,16 +215,11 @@ public class GameClient extends NetClient
 			}
 		}
 		
-		// Keep the order of packets if sent by multiple threads.
+		// Used by packet run() method.
-		_pendingPackets.add(packet);
+		packet.setPlayer(_player);
-		synchronized (_pendingPackets)
+		
-		{
+		// Send the packet data.
-			// Send the packet data.
+		super.sendPacket(packet);
-			super.sendPacket(packet);
-			
-			// Run packet implementation.
-			packet.run(_player);
-		}
 	}
 	
 	public void sendPacket(SystemMessageId systemMessageId)

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/gameserver/network/serverpackets/AbstractHtmlPacket.java

@@ -131,12 +131,14 @@ public abstract class AbstractHtmlPacket extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.clearHtmlActions(getScope());
 		}
+		
 		if (_disabledValidation)
 		{
 			return;

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/gameserver/network/serverpackets/CreatureSay.java

@@ -162,8 +162,9 @@ public class CreatureSay extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.broadcastSnoop(_chatType, _senderName, _text);

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/gameserver/network/serverpackets/ServerPacket.java

@@ -117,12 +117,22 @@ public abstract class ServerPacket extends WritablePacket
 		super(initialSize);
 	}
 	
+	private Player _player;
+	
 	/**
-	 * Method that runs after packet is sent.
+	 * @return the Player
-	 * @param player
 	 */
-	public void run(Player player)
+	public Player getPlayer()
 	{
+		return _player;
+	}
+	
+	/**
+	 * @param player the Player to set.
+	 */
+	public void setPlayer(Player player)
+	{
+		_player = player;
 	}
 	
 	protected void writeOptionalInt(int value)

L2J_Mobius_05.0_Salvation/java/org/l2jmobius/loginserver/LoginServer.java

@@ -136,6 +136,7 @@ public class LoginServer
 		final NetServer<LoginClient> server = new NetServer<>(Config.LOGIN_BIND_ADDRESS, Config.PORT_LOGIN, new LoginPacketHandler(), LoginClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(2000);
+		server.getNetConfig().setSendPoolSize(2000);
 		server.getNetConfig().setExecutePoolSize(2000);
 		server.getNetConfig().setPacketQueueLimit(10);
 		server.getNetConfig().setPacketFloodDisconnect(true);

L2J_Mobius_05.5_EtinasFate/dist/game/config/Server.ini

@@ -36,6 +36,11 @@ GameserverPort = 7777
 # Default: 100
 ClientReadPoolSize = 100
 
+# Client pool size for sending server packets.
+# Each pool is executed on a separate thread.
+# Default: 25
+ClientSendPoolSize = 25
+
 # Client pool size for executing client packets.
 # Each pool is executed on a separate thread.
 # Default: 50

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/Config.java

@@ -766,6 +766,7 @@ public class Config
 	public static int LOGIN_BLOCK_AFTER_BAN;
 	public static String GAMESERVER_HOSTNAME;
 	public static int CLIENT_READ_POOL_SIZE;
+	public static int CLIENT_SEND_POOL_SIZE;
 	public static int CLIENT_EXECUTE_POOL_SIZE;
 	public static int PACKET_QUEUE_LIMIT;
 	public static boolean PACKET_FLOOD_DISCONNECT;
@@ -1380,6 +1381,7 @@ public class Config
 			GAME_SERVER_LOGIN_PORT = serverConfig.getInt("LoginPort", 9014);
 			GAME_SERVER_LOGIN_HOST = serverConfig.getString("LoginHost", "127.0.0.1");
 			CLIENT_READ_POOL_SIZE = serverConfig.getInt("ClientReadPoolSize", 100);
+			CLIENT_SEND_POOL_SIZE = serverConfig.getInt("ClientSendPoolSize", 25);
 			CLIENT_EXECUTE_POOL_SIZE = serverConfig.getInt("ClientExecutePoolSize", 50);
 			PACKET_QUEUE_LIMIT = serverConfig.getInt("PacketQueueLimit", 80);
 			PACKET_FLOOD_DISCONNECT = serverConfig.getBoolean("PacketFloodDisconnect", false);

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/commons/network/ExecuteThread.java

@@ -16,6 +16,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 	
 	private final Set<E> _pool;
 	private final PacketHandlerInterface<E> _packetHandler;
+	private boolean _idle;
 	
 	public ExecuteThread(Set<E> pool, PacketHandlerInterface<E> packetHandler)
 	{
@@ -31,6 +32,8 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -40,7 +43,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						continue ITERATE;
 					}
 					
-					final byte[] data = client.getPacketData().poll();
+					final byte[] data = client.getReceivedData().poll();
 					if (data == null)
 					{
 						continue ITERATE;
@@ -64,16 +67,29 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						}
 					}
 					_packetHandler.handle(client, new ReadablePacket(data));
+					
+					_idle = false;
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
 				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/commons/network/NetClient.java

@@ -15,12 +15,15 @@ public class NetClient
 {
 	protected static final Logger LOGGER = Logger.getLogger(NetClient.class.getName());
 	
+	private final Queue<byte[]> _receivedData = new ConcurrentLinkedQueue<>();
+	private final Queue<WritablePacket> _sendPacketQueue = new ConcurrentLinkedQueue<>();
+	
 	private String _ip;
 	private Socket _socket;
 	private InputStream _inputStream;
 	private OutputStream _outputStream;
 	private NetConfig _netConfig;
-	private Queue<byte[]> _packetData;
+	
 	private byte[] _pendingData;
 	private int _pendingPacketSize;
 	
@@ -33,7 +36,6 @@ public class NetClient
 	{
 		_socket = socket;
 		_netConfig = netConfig;
-		_packetData = new ConcurrentLinkedQueue<>();
 		_ip = socket.getInetAddress().toString().substring(1); // Trim out /127.0.0.1
 		
 		try
@@ -82,10 +84,8 @@ public class NetClient
 			}
 		}
 		
-		if (_packetData != null)
+		_receivedData.clear();
-		{
+		_sendPacketQueue.clear();
-			_packetData.clear();
-		}
 		
 		if (_pendingData != null)
 		{
@@ -97,10 +97,10 @@ public class NetClient
 	 * Add packet data to the queue.
 	 * @param data
 	 */
-	public void addPacketData(byte[] data)
+	public void addReceivedData(byte[] data)
 	{
 		// Check packet flooding.
-		final int size = _packetData.size();
+		final int size = _receivedData.size();
 		if (size >= _netConfig.getPacketQueueLimit())
 		{
 			if (_netConfig.isPacketFloodDisconnect())
@@ -127,15 +127,15 @@ public class NetClient
 		}
 		
 		// Add to queue.
-		_packetData.add(data);
+		_receivedData.add(data);
 	}
 	
 	/**
-	 * @return the pending packet data.
+	 * @return the pending received data.
 	 */
-	public Queue<byte[]> getPacketData()
+	public Queue<byte[]> getReceivedData()
 	{
-		return _packetData;
+		return _receivedData;
 	}
 	
 	/**
@@ -172,34 +172,21 @@ public class NetClient
 		_pendingPacketSize = pendingPacketSize;
 	}
 	
+	/**
+	 * @return the writable packet queue waiting to be sent.
+	 */
+	public Queue<WritablePacket> getSendPacketQueue()
+	{
+		return _sendPacketQueue;
+	}
+	
 	/**
 	 * Sends a packet over the network using the default encryption.
 	 * @param packet The packet to send.
 	 */
 	public void sendPacket(WritablePacket packet)
 	{
-		if ((_socket == null) || !_socket.isConnected())
+		_sendPacketQueue.add(packet);
-		{
-			return;
-		}
-		
-		final byte[] sendableBytes = packet.getSendableBytes(getEncryption());
-		if (sendableBytes == null)
-		{
-			return;
-		}
-		
-		try
-		{
-			synchronized (this)
-			{
-				_outputStream.write(sendableBytes);
-				_outputStream.flush();
-			}
-		}
-		catch (Exception ignored)
-		{
-		}
 	}
 	
 	/**

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/commons/network/NetConfig.java

@@ -7,6 +7,7 @@ package org.l2jmobius.commons.network;
 public class NetConfig
 {
 	private int _readPoolSize = 100;
+	private int _sendPoolSize = 25;
 	private int _executePoolSize = 50;
 	private int _packetQueueLimit = 80;
 	private boolean _packetFloodDisconnect = false;
@@ -32,6 +33,23 @@ public class NetConfig
 		_readPoolSize = clientPoolSize;
 	}
 	
+	/**
+	 * @return the NetClient pool size for sending server packets.
+	 */
+	public int getSendPoolSize()
+	{
+		return _sendPoolSize;
+	}
+	
+	/**
+	 * Sets the NetClient pool size for sending server packets.
+	 * @param clientPoolSize
+	 */
+	public void setSendPoolSize(int clientPoolSize)
+	{
+		_sendPoolSize = clientPoolSize;
+	}
+	
 	/**
 	 * @return the NetClient pool size for executing client packets.
 	 */

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/commons/network/NetServer.java

@@ -20,6 +20,7 @@ public class NetServer<E extends NetClient>
 	protected static final Logger LOGGER = Logger.getLogger(NetServer.class.getName());
 	
 	protected final List<Set<E>> _clientReadPools = new LinkedList<>();
+	protected final List<Set<E>> _clientSendPools = new LinkedList<>();
 	protected final List<Set<E>> _clientExecutePools = new LinkedList<>();
 	protected final NetConfig _netConfig = new NetConfig();
 	protected final String _hostname;
@@ -155,6 +156,35 @@ public class NetServer<E extends NetClient>
 							_clientReadPools.add(newReadPool);
 						}
 						
+						// Add to send pool.
+						
+						// Find a pool that is not full.
+						boolean sendPoolFound = false;
+						SEND_POOLS: for (Set<E> pool : _clientSendPools)
+						{
+							if (pool.size() < _netConfig.getSendPoolSize())
+							{
+								pool.add(client);
+								sendPoolFound = true;
+								break SEND_POOLS;
+							}
+						}
+						
+						// All pools are full.
+						if (!sendPoolFound)
+						{
+							// Create a new client pool.
+							final Set<E> newSendPool = ConcurrentHashMap.newKeySet(_netConfig.getSendPoolSize());
+							newSendPool.add(client);
+							// Create a new task for the new pool.
+							final Thread sendThread = new Thread(new SendThread<>(newSendPool), _name + ": Packet send thread " + _clientSendPools.size());
+							sendThread.setPriority(Thread.MAX_PRIORITY);
+							sendThread.setDaemon(true);
+							sendThread.start();
+							// Add the new pool to the pool list.
+							_clientSendPools.add(newSendPool);
+						}
+						
 						// Add to execute pool.
 						
 						// Find a pool that is not full.

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/commons/network/ReadThread.java

@@ -14,6 +14,7 @@ public class ReadThread<E extends NetClient> implements Runnable
 	private final Set<E> _pool;
 	private final byte[] _sizeBuffer = new byte[2]; // Reusable size buffer.
 	private final byte[] _pendingSizeBuffer = new byte[1]; // Reusable pending size buffer.
+	private boolean _idle;
 	
 	public ReadThread(Set<E> pool)
 	{
@@ -28,6 +29,8 @@ public class ReadThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -80,14 +83,16 @@ public class ReadThread<E extends NetClient> implements Runnable
 									// Read was complete.
 									if (currentSize >= pendingPacketSize)
 									{
-										// Add packet data to client.
+										// Add received data to client.
-										client.addPacketData(mergedData);
+										client.addReceivedData(mergedData);
 										client.setPendingData(null);
 									}
 									else
 									{
 										client.setPendingData(mergedData);
 									}
+									
+									_idle = false;
 								}
 							}
 							continue ITERATE;
@@ -188,10 +193,12 @@ public class ReadThread<E extends NetClient> implements Runnable
 											client.setPendingData(pendindBytes);
 											client.setPendingPacketSize(packetSize);
 										}
-										else // Add packet data to client.
+										else // Add received data to client.
 										{
-											client.addPacketData(packetData);
+											client.addReceivedData(packetData);
 										}
+										
+										_idle = false;
 									}
 								}
 							}
@@ -206,15 +213,26 @@ public class ReadThread<E extends NetClient> implements Runnable
 						onDisconnection(client);
 					}
 				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/commons/network/SendThread.java

@@ -0,0 +1,106 @@
+package org.l2jmobius.commons.network;
+
+import java.io.OutputStream;
+import java.net.Socket;
+import java.util.Queue;
+import java.util.Set;
+
+/**
+ * @author Pantelis Andrianakis
+ * @since June 22nd 2023
+ * @param <E> extends NetClient
+ */
+public class SendThread<E extends NetClient> implements Runnable
+{
+	// Throttle packets sent per cycle to limit flooding from waiting one client.
+	private static final int MAX_PACKETS_SENT_PER_CYCLE = 2000;
+	
+	private final Set<E> _pool;
+	private boolean _idle;
+	
+	public SendThread(Set<E> pool)
+	{
+		_pool = pool;
+	}
+	
+	@Override
+	public void run()
+	{
+		while (true)
+		{
+			// No need to iterate when pool is empty.
+			if (!_pool.isEmpty())
+			{
+				_idle = true;
+				
+				// Iterate client pool.
+				ITERATE: for (E client : _pool)
+				{
+					final Socket socket = client.getSocket();
+					if (socket == null)
+					{
+						_pool.remove(client);
+						continue ITERATE;
+					}
+					
+					try
+					{
+						final Queue<WritablePacket> packetQueue = client.getSendPacketQueue();
+						if (packetQueue.isEmpty())
+						{
+							continue ITERATE;
+						}
+						
+						final OutputStream outputStream = client.getOutputStream();
+						SEND_CYCLE: for (int count = 0; count < MAX_PACKETS_SENT_PER_CYCLE; count++)
+						{
+							final WritablePacket writablePacket = packetQueue.poll();
+							if (writablePacket == null)
+							{
+								continue ITERATE;
+							}
+							
+							final byte[] sendableBytes = writablePacket.getSendableBytes(client.getEncryption());
+							if (sendableBytes == null)
+							{
+								continue SEND_CYCLE;
+							}
+							
+							// Send the packet data.
+							outputStream.write(sendableBytes);
+							outputStream.flush();
+							
+							// Run packet implementation.
+							writablePacket.run();
+							
+							_idle = false;
+						}
+					}
+					catch (Exception ignored)
+					{
+					}
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+			else // Remain idle for 1 second.
+			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+		}
+	}
+}

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/commons/network/WritablePacket.java

@@ -223,6 +223,14 @@ public abstract class WritablePacket
 		// Overridden by server implementation.
 	}
 	
+	/**
+	 * Method that runs after packet is sent.
+	 */
+	public void run()
+	{
+		// Overridden by server implementation.
+	}
+	
 	/**
 	 * @return <b>byte[]</b> of the sendable packet data, including a size header.
 	 */

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/gameserver/GameServer.java

@@ -468,6 +468,7 @@ public class GameServer
 		final NetServer<GameClient> server = new NetServer<>(Config.GAMESERVER_HOSTNAME, Config.PORT_GAME, new PacketHandler(), GameClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(Config.CLIENT_READ_POOL_SIZE);
+		server.getNetConfig().setSendPoolSize(Config.CLIENT_SEND_POOL_SIZE);
 		server.getNetConfig().setExecutePoolSize(Config.CLIENT_EXECUTE_POOL_SIZE);
 		server.getNetConfig().setPacketQueueLimit(Config.PACKET_QUEUE_LIMIT);
 		server.getNetConfig().setPacketFloodDisconnect(Config.PACKET_FLOOD_DISCONNECT);

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/gameserver/network/GameClient.java

@@ -20,8 +20,6 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.util.List;
-import java.util.Queue;
-import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -66,7 +64,6 @@ public class GameClient extends NetClient
 {
 	protected static final Logger LOGGER_ACCOUNTING = Logger.getLogger("accounting");
 	
-	private final Queue<ServerPacket> _pendingPackets = new ConcurrentLinkedQueue<>();
 	private final FloodProtectors _floodProtectors = new FloodProtectors(this);
 	private final ReentrantLock _playerLock = new ReentrantLock();
 	private ConnectionState _connectionState = ConnectionState.CONNECTED;
@@ -218,16 +215,11 @@ public class GameClient extends NetClient
 			}
 		}
 		
-		// Keep the order of packets if sent by multiple threads.
+		// Used by packet run() method.
-		_pendingPackets.add(packet);
+		packet.setPlayer(_player);
-		synchronized (_pendingPackets)
+		
-		{
+		// Send the packet data.
-			// Send the packet data.
+		super.sendPacket(packet);
-			super.sendPacket(packet);
-			
-			// Run packet implementation.
-			packet.run(_player);
-		}
 	}
 	
 	public void sendPacket(SystemMessageId systemMessageId)

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/gameserver/network/serverpackets/AbstractHtmlPacket.java

@@ -131,12 +131,14 @@ public abstract class AbstractHtmlPacket extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.clearHtmlActions(getScope());
 		}
+		
 		if (_disabledValidation)
 		{
 			return;

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/gameserver/network/serverpackets/CreatureSay.java

@@ -162,8 +162,9 @@ public class CreatureSay extends ServerPacket
 	}
 	
 	@Override
-	public void run(Player player)
+	public void run()
 	{
+		final Player player = getPlayer();
 		if (player != null)
 		{
 			player.broadcastSnoop(_chatType, _senderName, _text);

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/gameserver/network/serverpackets/ServerPacket.java

@@ -139,12 +139,22 @@ public abstract class ServerPacket extends WritablePacket
 		super(initialSize);
 	}
 	
+	private Player _player;
+	
 	/**
-	 * Method that runs after packet is sent.
+	 * @return the Player
-	 * @param player
 	 */
-	public void run(Player player)
+	public Player getPlayer()
 	{
+		return _player;
+	}
+	
+	/**
+	 * @param player the Player to set.
+	 */
+	public void setPlayer(Player player)
+	{
+		_player = player;
 	}
 	
 	protected void writeOptionalInt(int value)

L2J_Mobius_05.5_EtinasFate/java/org/l2jmobius/loginserver/LoginServer.java

@@ -136,6 +136,7 @@ public class LoginServer
 		final NetServer<LoginClient> server = new NetServer<>(Config.LOGIN_BIND_ADDRESS, Config.PORT_LOGIN, new LoginPacketHandler(), LoginClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(2000);
+		server.getNetConfig().setSendPoolSize(2000);
 		server.getNetConfig().setExecutePoolSize(2000);
 		server.getNetConfig().setPacketQueueLimit(10);
 		server.getNetConfig().setPacketFloodDisconnect(true);

L2J_Mobius_06.0_Fafurion/dist/game/config/Server.ini

@@ -36,6 +36,11 @@ GameserverPort = 7777
 # Default: 100
 ClientReadPoolSize = 100
 
+# Client pool size for sending server packets.
+# Each pool is executed on a separate thread.
+# Default: 25
+ClientSendPoolSize = 25
+
 # Client pool size for executing client packets.
 # Each pool is executed on a separate thread.
 # Default: 50

L2J_Mobius_06.0_Fafurion/java/org/l2jmobius/Config.java

@@ -767,6 +767,7 @@ public class Config
 	public static int LOGIN_BLOCK_AFTER_BAN;
 	public static String GAMESERVER_HOSTNAME;
 	public static int CLIENT_READ_POOL_SIZE;
+	public static int CLIENT_SEND_POOL_SIZE;
 	public static int CLIENT_EXECUTE_POOL_SIZE;
 	public static int PACKET_QUEUE_LIMIT;
 	public static boolean PACKET_FLOOD_DISCONNECT;
@@ -1401,6 +1402,7 @@ public class Config
 			GAME_SERVER_LOGIN_PORT = serverConfig.getInt("LoginPort", 9014);
 			GAME_SERVER_LOGIN_HOST = serverConfig.getString("LoginHost", "127.0.0.1");
 			CLIENT_READ_POOL_SIZE = serverConfig.getInt("ClientReadPoolSize", 100);
+			CLIENT_SEND_POOL_SIZE = serverConfig.getInt("ClientSendPoolSize", 25);
 			CLIENT_EXECUTE_POOL_SIZE = serverConfig.getInt("ClientExecutePoolSize", 50);
 			PACKET_QUEUE_LIMIT = serverConfig.getInt("PacketQueueLimit", 80);
 			PACKET_FLOOD_DISCONNECT = serverConfig.getBoolean("PacketFloodDisconnect", false);

L2J_Mobius_06.0_Fafurion/java/org/l2jmobius/commons/network/ExecuteThread.java

@@ -16,6 +16,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 	
 	private final Set<E> _pool;
 	private final PacketHandlerInterface<E> _packetHandler;
+	private boolean _idle;
 	
 	public ExecuteThread(Set<E> pool, PacketHandlerInterface<E> packetHandler)
 	{
@@ -31,6 +32,8 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -40,7 +43,7 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						continue ITERATE;
 					}
 					
-					final byte[] data = client.getPacketData().poll();
+					final byte[] data = client.getReceivedData().poll();
 					if (data == null)
 					{
 						continue ITERATE;
@@ -64,16 +67,29 @@ public class ExecuteThread<E extends NetClient> implements Runnable
 						}
 					}
 					_packetHandler.handle(client, new ReadablePacket(data));
+					
+					_idle = false;
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
 				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_06.0_Fafurion/java/org/l2jmobius/commons/network/NetClient.java

@@ -15,12 +15,15 @@ public class NetClient
 {
 	protected static final Logger LOGGER = Logger.getLogger(NetClient.class.getName());
 	
+	private final Queue<byte[]> _receivedData = new ConcurrentLinkedQueue<>();
+	private final Queue<WritablePacket> _sendPacketQueue = new ConcurrentLinkedQueue<>();
+	
 	private String _ip;
 	private Socket _socket;
 	private InputStream _inputStream;
 	private OutputStream _outputStream;
 	private NetConfig _netConfig;
-	private Queue<byte[]> _packetData;
+	
 	private byte[] _pendingData;
 	private int _pendingPacketSize;
 	
@@ -33,7 +36,6 @@ public class NetClient
 	{
 		_socket = socket;
 		_netConfig = netConfig;
-		_packetData = new ConcurrentLinkedQueue<>();
 		_ip = socket.getInetAddress().toString().substring(1); // Trim out /127.0.0.1
 		
 		try
@@ -82,10 +84,8 @@ public class NetClient
 			}
 		}
 		
-		if (_packetData != null)
+		_receivedData.clear();
-		{
+		_sendPacketQueue.clear();
-			_packetData.clear();
-		}
 		
 		if (_pendingData != null)
 		{
@@ -97,10 +97,10 @@ public class NetClient
 	 * Add packet data to the queue.
 	 * @param data
 	 */
-	public void addPacketData(byte[] data)
+	public void addReceivedData(byte[] data)
 	{
 		// Check packet flooding.
-		final int size = _packetData.size();
+		final int size = _receivedData.size();
 		if (size >= _netConfig.getPacketQueueLimit())
 		{
 			if (_netConfig.isPacketFloodDisconnect())
@@ -127,15 +127,15 @@ public class NetClient
 		}
 		
 		// Add to queue.
-		_packetData.add(data);
+		_receivedData.add(data);
 	}
 	
 	/**
-	 * @return the pending packet data.
+	 * @return the pending received data.
 	 */
-	public Queue<byte[]> getPacketData()
+	public Queue<byte[]> getReceivedData()
 	{
-		return _packetData;
+		return _receivedData;
 	}
 	
 	/**
@@ -172,34 +172,21 @@ public class NetClient
 		_pendingPacketSize = pendingPacketSize;
 	}
 	
+	/**
+	 * @return the writable packet queue waiting to be sent.
+	 */
+	public Queue<WritablePacket> getSendPacketQueue()
+	{
+		return _sendPacketQueue;
+	}
+	
 	/**
 	 * Sends a packet over the network using the default encryption.
 	 * @param packet The packet to send.
 	 */
 	public void sendPacket(WritablePacket packet)
 	{
-		if ((_socket == null) || !_socket.isConnected())
+		_sendPacketQueue.add(packet);
-		{
-			return;
-		}
-		
-		final byte[] sendableBytes = packet.getSendableBytes(getEncryption());
-		if (sendableBytes == null)
-		{
-			return;
-		}
-		
-		try
-		{
-			synchronized (this)
-			{
-				_outputStream.write(sendableBytes);
-				_outputStream.flush();
-			}
-		}
-		catch (Exception ignored)
-		{
-		}
 	}
 	
 	/**

L2J_Mobius_06.0_Fafurion/java/org/l2jmobius/commons/network/NetConfig.java

@@ -7,6 +7,7 @@ package org.l2jmobius.commons.network;
 public class NetConfig
 {
 	private int _readPoolSize = 100;
+	private int _sendPoolSize = 25;
 	private int _executePoolSize = 50;
 	private int _packetQueueLimit = 80;
 	private boolean _packetFloodDisconnect = false;
@@ -32,6 +33,23 @@ public class NetConfig
 		_readPoolSize = clientPoolSize;
 	}
 	
+	/**
+	 * @return the NetClient pool size for sending server packets.
+	 */
+	public int getSendPoolSize()
+	{
+		return _sendPoolSize;
+	}
+	
+	/**
+	 * Sets the NetClient pool size for sending server packets.
+	 * @param clientPoolSize
+	 */
+	public void setSendPoolSize(int clientPoolSize)
+	{
+		_sendPoolSize = clientPoolSize;
+	}
+	
 	/**
 	 * @return the NetClient pool size for executing client packets.
 	 */

L2J_Mobius_06.0_Fafurion/java/org/l2jmobius/commons/network/NetServer.java

@@ -20,6 +20,7 @@ public class NetServer<E extends NetClient>
 	protected static final Logger LOGGER = Logger.getLogger(NetServer.class.getName());
 	
 	protected final List<Set<E>> _clientReadPools = new LinkedList<>();
+	protected final List<Set<E>> _clientSendPools = new LinkedList<>();
 	protected final List<Set<E>> _clientExecutePools = new LinkedList<>();
 	protected final NetConfig _netConfig = new NetConfig();
 	protected final String _hostname;
@@ -155,6 +156,35 @@ public class NetServer<E extends NetClient>
 							_clientReadPools.add(newReadPool);
 						}
 						
+						// Add to send pool.
+						
+						// Find a pool that is not full.
+						boolean sendPoolFound = false;
+						SEND_POOLS: for (Set<E> pool : _clientSendPools)
+						{
+							if (pool.size() < _netConfig.getSendPoolSize())
+							{
+								pool.add(client);
+								sendPoolFound = true;
+								break SEND_POOLS;
+							}
+						}
+						
+						// All pools are full.
+						if (!sendPoolFound)
+						{
+							// Create a new client pool.
+							final Set<E> newSendPool = ConcurrentHashMap.newKeySet(_netConfig.getSendPoolSize());
+							newSendPool.add(client);
+							// Create a new task for the new pool.
+							final Thread sendThread = new Thread(new SendThread<>(newSendPool), _name + ": Packet send thread " + _clientSendPools.size());
+							sendThread.setPriority(Thread.MAX_PRIORITY);
+							sendThread.setDaemon(true);
+							sendThread.start();
+							// Add the new pool to the pool list.
+							_clientSendPools.add(newSendPool);
+						}
+						
 						// Add to execute pool.
 						
 						// Find a pool that is not full.

L2J_Mobius_06.0_Fafurion/java/org/l2jmobius/commons/network/ReadThread.java

@@ -14,6 +14,7 @@ public class ReadThread<E extends NetClient> implements Runnable
 	private final Set<E> _pool;
 	private final byte[] _sizeBuffer = new byte[2]; // Reusable size buffer.
 	private final byte[] _pendingSizeBuffer = new byte[1]; // Reusable pending size buffer.
+	private boolean _idle;
 	
 	public ReadThread(Set<E> pool)
 	{
@@ -28,6 +29,8 @@ public class ReadThread<E extends NetClient> implements Runnable
 			// No need to iterate when pool is empty.
 			if (!_pool.isEmpty())
 			{
+				_idle = true;
+				
 				// Iterate client pool.
 				ITERATE: for (E client : _pool)
 				{
@@ -80,14 +83,16 @@ public class ReadThread<E extends NetClient> implements Runnable
 									// Read was complete.
 									if (currentSize >= pendingPacketSize)
 									{
-										// Add packet data to client.
+										// Add received data to client.
-										client.addPacketData(mergedData);
+										client.addReceivedData(mergedData);
 										client.setPendingData(null);
 									}
 									else
 									{
 										client.setPendingData(mergedData);
 									}
+									
+									_idle = false;
 								}
 							}
 							continue ITERATE;
@@ -188,10 +193,12 @@ public class ReadThread<E extends NetClient> implements Runnable
 											client.setPendingData(pendindBytes);
 											client.setPendingPacketSize(packetSize);
 										}
-										else // Add packet data to client.
+										else // Add received data to client.
 										{
-											client.addPacketData(packetData);
+											client.addReceivedData(packetData);
 										}
+										
+										_idle = false;
 									}
 								}
 							}
@@ -206,15 +213,26 @@ public class ReadThread<E extends NetClient> implements Runnable
 						onDisconnection(client);
 					}
 				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
-			
+			else // Remain idle for 1 second.
-			// Prevent high CPU caused by repeatedly looping.
-			try
-			{
-				Thread.sleep(1);
-			}
-			catch (Exception ignored)
 			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
 			}
 		}
 	}

L2J_Mobius_06.0_Fafurion/java/org/l2jmobius/commons/network/SendThread.java

@@ -0,0 +1,106 @@
+package org.l2jmobius.commons.network;
+
+import java.io.OutputStream;
+import java.net.Socket;
+import java.util.Queue;
+import java.util.Set;
+
+/**
+ * @author Pantelis Andrianakis
+ * @since June 22nd 2023
+ * @param <E> extends NetClient
+ */
+public class SendThread<E extends NetClient> implements Runnable
+{
+	// Throttle packets sent per cycle to limit flooding from waiting one client.
+	private static final int MAX_PACKETS_SENT_PER_CYCLE = 2000;
+	
+	private final Set<E> _pool;
+	private boolean _idle;
+	
+	public SendThread(Set<E> pool)
+	{
+		_pool = pool;
+	}
+	
+	@Override
+	public void run()
+	{
+		while (true)
+		{
+			// No need to iterate when pool is empty.
+			if (!_pool.isEmpty())
+			{
+				_idle = true;
+				
+				// Iterate client pool.
+				ITERATE: for (E client : _pool)
+				{
+					final Socket socket = client.getSocket();
+					if (socket == null)
+					{
+						_pool.remove(client);
+						continue ITERATE;
+					}
+					
+					try
+					{
+						final Queue<WritablePacket> packetQueue = client.getSendPacketQueue();
+						if (packetQueue.isEmpty())
+						{
+							continue ITERATE;
+						}
+						
+						final OutputStream outputStream = client.getOutputStream();
+						SEND_CYCLE: for (int count = 0; count < MAX_PACKETS_SENT_PER_CYCLE; count++)
+						{
+							final WritablePacket writablePacket = packetQueue.poll();
+							if (writablePacket == null)
+							{
+								continue ITERATE;
+							}
+							
+							final byte[] sendableBytes = writablePacket.getSendableBytes(client.getEncryption());
+							if (sendableBytes == null)
+							{
+								continue SEND_CYCLE;
+							}
+							
+							// Send the packet data.
+							outputStream.write(sendableBytes);
+							outputStream.flush();
+							
+							// Run packet implementation.
+							writablePacket.run();
+							
+							_idle = false;
+						}
+					}
+					catch (Exception ignored)
+					{
+					}
+				}
+				
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(_idle ? 10 : 1);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+			else // Remain idle for 1 second.
+			{
+				// Prevent high CPU caused by repeatedly looping.
+				try
+				{
+					Thread.sleep(1000);
+				}
+				catch (Exception ignored)
+				{
+				}
+			}
+		}
+	}
+}

L2J_Mobius_06.0_Fafurion/java/org/l2jmobius/commons/network/WritablePacket.java

@@ -223,6 +223,14 @@ public abstract class WritablePacket
 		// Overridden by server implementation.
 	}
 	
+	/**
+	 * Method that runs after packet is sent.
+	 */
+	public void run()
+	{
+		// Overridden by server implementation.
+	}
+	
 	/**
 	 * @return <b>byte[]</b> of the sendable packet data, including a size header.
 	 */

L2J_Mobius_06.0_Fafurion/java/org/l2jmobius/gameserver/GameServer.java

@@ -470,6 +470,7 @@ public class GameServer
 		final NetServer<GameClient> server = new NetServer<>(Config.GAMESERVER_HOSTNAME, Config.PORT_GAME, new PacketHandler(), GameClient::new);
 		server.setName(getClass().getSimpleName());
 		server.getNetConfig().setReadPoolSize(Config.CLIENT_READ_POOL_SIZE);
+		server.getNetConfig().setSendPoolSize(Config.CLIENT_SEND_POOL_SIZE);
 		server.getNetConfig().setExecutePoolSize(Config.CLIENT_EXECUTE_POOL_SIZE);
 		server.getNetConfig().setPacketQueueLimit(Config.PACKET_QUEUE_LIMIT);
 		server.getNetConfig().setPacketFloodDisconnect(Config.PACKET_FLOOD_DISCONNECT);