From 141ada19b00fb9d0dd1a260d86d97bbb709a0f5e Mon Sep 17 00:00:00 2001
From: Giacomo Pozzoni <giacomopoz@gmail.com>
Date: Sat, 30 May 2020 15:43:54 +0000
Subject: Cherry pick some db commits (#24713)

* Core/DBLayer: Implement async transaction completion callbacks

(cherry picked from commit 0f0ca3a9194d76afa0227943e86469ad8368c5e2)

# Conflicts:
#	src/server/bnetserver/REST/LoginRESTService.cpp
#	src/server/bnetserver/Server/Session.cpp
#	src/server/bnetserver/Server/Session.h
#	src/server/database/Database/Transaction.cpp
#	src/server/game/Handlers/CharacterHandler.cpp
#	src/server/game/Handlers/SpellHandler.cpp
#	src/server/game/Server/WorldSession.cpp
#	src/server/game/Server/WorldSocket.cpp
#	src/server/game/Server/WorldSocket.h

* Core/Misc: Fixed char enum packet sometimes not showing newly created character when client latency is too low

(cherry picked from commit fc9d2e728e5c21bd2a1645a29be60d0e280ad940)

# Conflicts:
#	src/server/game/Handlers/CharacterHandler.cpp

* Fix no-pch build

* Core/Player: Wait for correct transaction on character creation

(cherry picked from commit 01c68b2aa2ed25ea9b4c007f238a0e958f6525b1)

# Conflicts:
#	src/server/game/Entities/Player/Player.cpp

* Fix warning

* Remove unused login transaction

Co-authored-by: Shauren <shauren.trinity@gmail.com>
---
 src/server/database/Database/Transaction.cpp | 56 +++++++++++++++++++++++++++-
 1 file changed, 54 insertions(+), 2 deletions(-)

(limited to 'src/server/database/Database/Transaction.cpp')

diff --git a/src/server/database/Database/Transaction.cpp b/src/server/database/Database/Transaction.cpp
index be5c28bceb3..9b2178d2c4b 100644
--- a/src/server/database/Database/Transaction.cpp
+++ b/src/server/database/Database/Transaction.cpp
@@ -71,7 +71,7 @@ void TransactionBase::Cleanup()
 
 bool TransactionTask::Execute()
 {
-    int errorCode = m_conn->ExecuteTransaction(m_trans);
+    int errorCode = TryExecute();
     if (!errorCode)
         return true;
 
@@ -86,7 +86,7 @@ bool TransactionTask::Execute()
 
         for (uint32 loopDuration = 0, startMSTime = getMSTime(); loopDuration <= DEADLOCK_MAX_RETRY_TIME_MS; loopDuration = GetMSTimeDiffToNow(startMSTime))
         {
-            if (!m_conn->ExecuteTransaction(m_trans))
+            if (!TryExecute())
                 return true;
 
             TC_LOG_WARN("sql.sql", "Deadlocked SQL Transaction, retrying. Loop timer: %u ms, Thread Id: %s", loopDuration, threadId.c_str());
@@ -96,7 +96,59 @@ bool TransactionTask::Execute()
     }
 
     // Clean up now.
+    CleanupOnFailure();
+
+    return false;
+}
+
+int TransactionTask::TryExecute()
+{
+    return m_conn->ExecuteTransaction(m_trans);
+}
+
+void TransactionTask::CleanupOnFailure()
+{
     m_trans->Cleanup();
+}
+
+bool TransactionWithResultTask::Execute()
+{
+    int errorCode = TryExecute();
+    if (!errorCode)
+    {
+        m_result.set_value(true);
+        return true;
+    }
+
+    if (errorCode == ER_LOCK_DEADLOCK)
+    {
+        // Make sure only 1 async thread retries a transaction so they don't keep dead-locking each other
+        std::lock_guard<std::mutex> lock(_deadlockLock);
+        uint8 loopBreaker = 5;  // Handle MySQL Errno 1213 without extending deadlock to the core itself
+        for (uint8 i = 0; i < loopBreaker; ++i)
+        {
+            if (!TryExecute())
+            {
+                m_result.set_value(true);
+                return true;
+            }
+        }
+    }
+
+    // Clean up now.
+    CleanupOnFailure();
+    m_result.set_value(false);
+
+    return false;
+}
+
+bool TransactionCallback::InvokeIfReady()
+{
+    if (m_future.valid() && m_future.wait_for(std::chrono::seconds(0)) == std::future_status::ready)
+    {
+        m_callback(m_future.get());
+        return true;
+    }
 
     return false;
 }
-- 
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