Core/Networking: Switch to intrusive variant of MPSC queue to halve the number of memory allocations for packet sending (#24659)

2 files changed, 16 insertions, 13 deletions

diff --git a/src/server/game/Server/WorldSocket.cpp b/src/server/game/Server/WorldSocket.cpp
index 17363de5eb8..0e65704076d 100644
--- a/src/server/game/Server/WorldSocket.cpp
+++ b/src/server/game/Server/WorldSocket.cpp
@@ -31,17 +31,6 @@
 #include "WorldSession.h"
 #include <memory>
 
-class EncryptablePacket : public WorldPacket
-{
-public:
-    EncryptablePacket(WorldPacket const& packet, bool encrypt) : WorldPacket(packet), _encrypt(encrypt) { }
-
-    bool NeedsEncryption() const { return _encrypt; }
-
-private:
-    bool _encrypt;
-};
-
 using boost::asio::ip::tcp;
 
 WorldSocket::WorldSocket(tcp::socket&& socket)
diff --git a/src/server/game/Server/WorldSocket.h b/src/server/game/Server/WorldSocket.h
index 8bf230e8005..6f6b0848423 100644
--- a/src/server/game/Server/WorldSocket.h
+++ b/src/server/game/Server/WorldSocket.h
@@ -30,7 +30,21 @@
 #include <boost/asio/ip/tcp.hpp>
 
 using boost::asio::ip::tcp;
-class EncryptablePacket;
+class EncryptablePacket : public WorldPacket
+{
+public:
+    EncryptablePacket(WorldPacket const& packet, bool encrypt) : WorldPacket(packet), _encrypt(encrypt)
+    {
+        SocketQueueLink.store(nullptr, std::memory_order_relaxed);
+    }
+
+    bool NeedsEncryption() const { return _encrypt; }
+
+    std::atomic<EncryptablePacket*> SocketQueueLink;
+
+private:
+    bool _encrypt;
+};
 
 namespace WorldPackets
 {
@@ -110,7 +124,7 @@ private:
 
     MessageBuffer _headerBuffer;
     MessageBuffer _packetBuffer;
-    MPSCQueue<EncryptablePacket> _bufferQueue;
+    MPSCQueue<EncryptablePacket, &EncryptablePacket::SocketQueueLink> _bufferQueue;
     std::size_t _sendBufferSize;
 
     QueryCallbackProcessor _queryProcessor;