Network: Rework reconnection case to fix slow cpu race conditions

cmangos/issues#3676
cmangos · Feb 14, 2024 · 019f160 · 019f160
1 parent 98c85db
commit 019f160
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Showing 3 changed files with 29 additions and 44 deletions.
diff --git a/src/game/Server/WorldSession.cpp b/src/game/Server/WorldSession.cpp
@@ -162,7 +162,6 @@ void WorldSession::SetInCharSelection()
 
 bool WorldSession::RequestNewSocket(WorldSocket* socket)
 {
-    std::lock_guard<std::mutex> guard(m_recvQueueLock);
     if (m_requestSocket)
         return false;
 
@@ -482,6 +481,7 @@ bool WorldSession::Update(uint32 /*diff*/)
         {
             if (m_requestSocket)
             {
+                std::lock_guard<std::mutex> guard(m_recvQueueLock);
                 if (!IsOffline())
                     SetOffline();
 
@@ -1282,14 +1282,9 @@ void WorldSession::InitializeAnticheat(const BigNumber& K)
     m_anticheat = sAnticheatLib->NewSession(this, K);
 }
 
-void WorldSession::AssignAnticheat()
+void WorldSession::AssignAnticheat(std::unique_ptr<SessionAnticheatInterface>&& anticheat)
 {
-    m_anticheat = std::move(m_delayedAnticheat);
-}
-
-void WorldSession::SetDelayedAnticheat(std::unique_ptr<SessionAnticheatInterface>&& anticheat)
-{
-    m_delayedAnticheat = std::move(anticheat);
+    m_anticheat = std::move(anticheat);
 }
 
 #ifdef BUILD_PLAYERBOT

diff --git a/src/game/Server/WorldSession.h b/src/game/Server/WorldSession.h
@@ -282,8 +282,7 @@ class WorldSession
         void SetExpansion(uint8 expansion);
 
         void InitializeAnticheat(const BigNumber& K);
-        void AssignAnticheat();
-        void SetDelayedAnticheat(std::unique_ptr<SessionAnticheatInterface>&& anticheat);
+        void AssignAnticheat(std::unique_ptr<SessionAnticheatInterface>&& anticheat);
         SessionAnticheatInterface* GetAnticheat() const { return m_anticheat.get(); }
 
 #ifdef BUILD_PLAYERBOT
@@ -949,7 +948,6 @@ class WorldSession
         uint32 m_accountMaxLevel;
         uint32 m_orderCounter;
         uint32 m_lastAnticheatUpdate;
-        std::unique_ptr<SessionAnticheatInterface> m_delayedAnticheat;
         std::unique_ptr<SessionAnticheatInterface> m_anticheat;
 
         time_t _logoutTime;                                 // when logout will be processed after a logout request

diff --git a/src/game/Server/WorldSocket.cpp b/src/game/Server/WorldSocket.cpp
@@ -503,45 +503,37 @@ bool WorldSocket::HandleAuthSession(WorldPacket& recvPacket)
 
     if (m_session)
     {
-        // Session exist so player is reconnecting
-        // check if we can request a new socket
-        if (!m_session->RequestNewSocket(this))
-            return false;
-
-        uint32 counter = 0;
+        DEBUG_LOG("WorldSocket::HandleAuthSession reconnecting for account '%s' from %s", account.c_str(), address.c_str());
 
-        // wait session going to be ready
-        while (m_session->GetState() != WORLD_SESSION_STATE_CHAR_SELECTION)
+        // defer operation to session thread context to avoid any race conditions
+        auto self = shared_from_this();
+        m_session->GetMessager().AddMessage([self, ClientBuild, clientOS, clientPlatform, account, address = address, K, id, recvPacket = recvPacket](WorldSession* session)
         {
-            ++counter;
-            // just wait
-            std::this_thread::sleep_for(std::chrono::milliseconds(1));
-
-            if (IsClosed() || counter > 20)
-                return false;
-        }
+            // Session exist so player is reconnecting
+            // check if we can request a new socket
+            if (!session->RequestNewSocket(self.get()))
+                return;
 
-        m_session->SetGameBuild(ClientBuild);
-        m_session->SetOS(clientOS);
-        m_session->SetPlatform(clientPlatform);
+            DEBUG_LOG("WorldSocket::HandleAuthSession reconnect loading data for account '%s' from %s", account.c_str(), address.c_str());
+            session->SetGameBuild(ClientBuild);
+            session->SetOS(clientOS);
+            session->SetPlatform(clientPlatform);
 
-        std::unique_ptr<SessionAnticheatInterface> anticheat = sAnticheatLib->NewSession(m_session, K);
+            std::unique_ptr<SessionAnticheatInterface> anticheat = sAnticheatLib->NewSession(session, K);
 
-        // when false, the client sent invalid addon data.  kick!
-        WorldPacket addonPacket; // yes its copypasted atm cos of reconnect
-        if (!anticheat->ReadAddonInfo(&recvPacket, addonPacket))
-        {
-            sLog.outBasic("WorldSocket::HandleAuthSession: Account %s (id %u) IP %s sent bad addon info.  Kicking.",
-                account.c_str(), id, address.c_str());
-            return false;
-        }
-        else
-            SendPacket(addonPacket);
+            // when false, the client sent invalid addon data.  kick!
+            WorldPacket addonPacket; // yes its copypasted atm cos of reconnect
+            if (!anticheat->ReadAddonInfo(const_cast<WorldPacket*>(&recvPacket), addonPacket))
+            {
+                sLog.outBasic("WorldSocket::HandleAuthSession: Account %s (id %u) IP %s sent bad addon info.  Kicking.",
+                    account.c_str(), id, address.c_str());
+                return;
+            }
+            else
+                self->SendPacket(addonPacket);
 
-        m_session->SetDelayedAnticheat(std::move(anticheat));
-        m_session->GetMessager().AddMessage([](WorldSession* session)
-        {
-            session->AssignAnticheat();
+            DEBUG_LOG("WorldSocket::HandleAuthSession assigning anticheat for '%s' from %s", account.c_str(), address.c_str());
+            session->AssignAnticheat(std::move(anticheat));
         });
     }
     else