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>

23 files changed, 280 insertions, 159 deletions

diff --git a/src/common/Utilities/AsyncCallbackProcessor.h b/src/common/Utilities/AsyncCallbackProcessor.h
new file mode 100644
index 00000000000..76781f49425
--- /dev/null
+++ b/src/common/Utilities/AsyncCallbackProcessor.h
@@ -0,0 +1,63 @@
+/*
+ * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef AsyncCallbackProcessor_h__
+#define AsyncCallbackProcessor_h__
+
+#include "Define.h"
+#include <algorithm>
+#include <vector>
+
+//template <class T>
+//concept AsyncCallback = requires(T t) { { t.InvokeIfReady() } -> std::convertible_to<bool> };
+
+template<typename T> // requires AsyncCallback<T>
+class AsyncCallbackProcessor
+{
+public:
+    AsyncCallbackProcessor() = default;
+    ~AsyncCallbackProcessor() = default;
+
+    T& AddCallback(T&& query)
+    {
+        _callbacks.emplace_back(std::move(query));
+        return _callbacks.back();
+    }
+
+    void ProcessReadyCallbacks()
+    {
+        if (_callbacks.empty())
+            return;
+
+        std::vector<T> updateCallbacks{ std::move(_callbacks) };
+
+        updateCallbacks.erase(std::remove_if(updateCallbacks.begin(), updateCallbacks.end(), [](T& callback)
+        {
+            return callback.InvokeIfReady();
+        }), updateCallbacks.end());
+
+        _callbacks.insert(_callbacks.end(), std::make_move_iterator(updateCallbacks.begin()), std::make_move_iterator(updateCallbacks.end()));
+    }
+
+private:
+    AsyncCallbackProcessor(AsyncCallbackProcessor const&) = delete;
+    AsyncCallbackProcessor& operator=(AsyncCallbackProcessor const&) = delete;
+
+    std::vector<T> _callbacks;
+};
+
+#endif // AsyncCallbackProcessor_h__
diff --git a/src/server/authserver/Server/AuthSession.cpp b/src/server/authserver/Server/AuthSession.cpp
index 0cf0f83d346..60167564f35 100644
--- a/src/server/authserver/Server/AuthSession.cpp
+++ b/src/server/authserver/Server/AuthSession.cpp
@@ -175,7 +175,7 @@ void AuthSession::Start()
     LoginDatabasePreparedStatement* stmt = LoginDatabase.GetPreparedStatement(LOGIN_SEL_IP_INFO);
     stmt->setString(0, ip_address);
 
-    _queryProcessor.AddQuery(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&AuthSession::CheckIpCallback, this, std::placeholders::_1)));
+    _queryProcessor.AddCallback(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&AuthSession::CheckIpCallback, this, std::placeholders::_1)));
 }
 
 bool AuthSession::Update()
@@ -183,7 +183,7 @@ bool AuthSession::Update()
     if (!AuthSocket::Update())
         return false;
 
-    _queryProcessor.ProcessReadyQueries();
+    _queryProcessor.ProcessReadyCallbacks();
 
     return true;
 }
@@ -308,7 +308,7 @@ bool AuthSession::HandleLogonChallenge()
     LoginDatabasePreparedStatement* stmt = LoginDatabase.GetPreparedStatement(LOGIN_SEL_LOGONCHALLENGE);
     stmt->setString(0, login);
 
-    _queryProcessor.AddQuery(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&AuthSession::LogonChallengeCallback, this, std::placeholders::_1)));
+    _queryProcessor.AddCallback(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&AuthSession::LogonChallengeCallback, this, std::placeholders::_1)));
     return true;
 }
 
@@ -736,7 +736,7 @@ bool AuthSession::HandleReconnectChallenge()
     LoginDatabasePreparedStatement* stmt = LoginDatabase.GetPreparedStatement(LOGIN_SEL_RECONNECTCHALLENGE);
     stmt->setString(0, login);
 
-    _queryProcessor.AddQuery(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&AuthSession::ReconnectChallengeCallback, this, std::placeholders::_1)));
+    _queryProcessor.AddCallback(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&AuthSession::ReconnectChallengeCallback, this, std::placeholders::_1)));
     return true;
 }
 
@@ -820,7 +820,7 @@ bool AuthSession::HandleRealmList()
     LoginDatabasePreparedStatement* stmt = LoginDatabase.GetPreparedStatement(LOGIN_SEL_REALM_CHARACTER_COUNTS);
     stmt->setUInt32(0, _accountInfo.Id);
 
-    _queryProcessor.AddQuery(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&AuthSession::RealmListCallback, this, std::placeholders::_1)));
+    _queryProcessor.AddCallback(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&AuthSession::RealmListCallback, this, std::placeholders::_1)));
     _status = STATUS_WAITING_FOR_REALM_LIST;
     return true;
 }
diff --git a/src/server/authserver/Server/AuthSession.h b/src/server/authserver/Server/AuthSession.h
index 51f422cb09b..86bbb4a6f9a 100644
--- a/src/server/authserver/Server/AuthSession.h
+++ b/src/server/authserver/Server/AuthSession.h
@@ -18,13 +18,13 @@
 #ifndef __AUTHSESSION_H__
 #define __AUTHSESSION_H__
 
+#include "AsyncCallbackProcessor.h"
 #include "BigNumber.h"
 #include "ByteBuffer.h"
 #include "Common.h"
 #include "Optional.h"
 #include "Socket.h"
 #include "QueryResult.h"
-#include "QueryCallbackProcessor.h"
 #include <memory>
 #include <boost/asio/ip/tcp.hpp>
 
diff --git a/src/server/database/Database/DatabaseEnvFwd.h b/src/server/database/Database/DatabaseEnvFwd.h
index dd8cc464cae..930957fb898 100644
--- a/src/server/database/Database/DatabaseEnvFwd.h
+++ b/src/server/database/Database/DatabaseEnvFwd.h
@@ -24,9 +24,9 @@
 class Field;
 
 class ResultSet;
-typedef std::shared_ptr<ResultSet> QueryResult;
-typedef std::future<QueryResult> QueryResultFuture;
-typedef std::promise<QueryResult> QueryResultPromise;
+using QueryResult = std::shared_ptr<ResultSet>;
+using QueryResultFuture = std::future<QueryResult>;
+using QueryResultPromise = std::promise<QueryResult>;
 
 class CharacterDatabaseConnection;
 class LoginDatabaseConnection;
@@ -42,17 +42,27 @@ using LoginDatabasePreparedStatement = PreparedStatement<LoginDatabaseConnection
 using WorldDatabasePreparedStatement = PreparedStatement<WorldDatabaseConnection>;
 
 class PreparedResultSet;
-typedef std::shared_ptr<PreparedResultSet> PreparedQueryResult;
-typedef std::future<PreparedQueryResult> PreparedQueryResultFuture;
-typedef std::promise<PreparedQueryResult> PreparedQueryResultPromise;
+using PreparedQueryResult = std::shared_ptr<PreparedResultSet>;
+using PreparedQueryResultFuture = std::future<PreparedQueryResult>;
+using PreparedQueryResultPromise = std::promise<PreparedQueryResult>;
 
 class QueryCallback;
 
+template<typename T>
+class AsyncCallbackProcessor;
+
+using QueryCallbackProcessor = AsyncCallbackProcessor<QueryCallback>;
+
 class TransactionBase;
 
+using TransactionFuture = std::future<bool>;
+using TransactionPromise = std::promise<bool>;
+
 template<typename T>
 class Transaction;
 
+class TransactionCallback;
+
 template<typename T>
 using SQLTransaction = std::shared_ptr<Transaction<T>>;
 
@@ -61,8 +71,8 @@ using LoginDatabaseTransaction = SQLTransaction<LoginDatabaseConnection>;
 using WorldDatabaseTransaction = SQLTransaction<WorldDatabaseConnection>;
 
 class SQLQueryHolderBase;
-typedef std::future<SQLQueryHolderBase*> QueryResultHolderFuture;
-typedef std::promise<SQLQueryHolderBase*> QueryResultHolderPromise;
+using QueryResultHolderFuture = std::future<SQLQueryHolderBase*>;
+using QueryResultHolderPromise = std::promise<SQLQueryHolderBase*>;
 
 template<typename T>
 class SQLQueryHolder;
diff --git a/src/server/database/Database/DatabaseWorkerPool.cpp b/src/server/database/Database/DatabaseWorkerPool.cpp
index 75bda12ffbf..94478f7e18f 100644
--- a/src/server/database/Database/DatabaseWorkerPool.cpp
+++ b/src/server/database/Database/DatabaseWorkerPool.cpp
@@ -261,6 +261,32 @@ void DatabaseWorkerPool<T>::CommitTransaction(SQLTransaction<T> transaction)
 }
 
 template <class T>
+TransactionCallback DatabaseWorkerPool<T>::AsyncCommitTransaction(SQLTransaction<T> transaction)
+{
+#ifdef TRINITY_DEBUG
+    //! Only analyze transaction weaknesses in Debug mode.
+    //! Ideally we catch the faults in Debug mode and then correct them,
+    //! so there's no need to waste these CPU cycles in Release mode.
+    switch (transaction->GetSize())
+    {
+        case 0:
+            TC_LOG_DEBUG("sql.driver", "Transaction contains 0 queries. Not executing.");
+            return;
+        case 1:
+            TC_LOG_DEBUG("sql.driver", "Warning: Transaction only holds 1 query, consider removing Transaction context in code.");
+            break;
+        default:
+            break;
+    }
+#endif // TRINITY_DEBUG
+
+    TransactionWithResultTask* task = new TransactionWithResultTask(transaction);
+    TransactionFuture result = task->GetFuture();
+    Enqueue(task);
+    return TransactionCallback(std::move(result));
+}
+
+template <class T>
 void DatabaseWorkerPool<T>::DirectCommitTransaction(SQLTransaction<T>& transaction)
 {
     T* connection = GetFreeConnection();
diff --git a/src/server/database/Database/DatabaseWorkerPool.h b/src/server/database/Database/DatabaseWorkerPool.h
index 8824dc38d85..f72817c3a8f 100644
--- a/src/server/database/Database/DatabaseWorkerPool.h
+++ b/src/server/database/Database/DatabaseWorkerPool.h
@@ -173,6 +173,10 @@ class DatabaseWorkerPool
         //! were appended to the transaction will be respected during execution.
         void CommitTransaction(SQLTransaction<T> transaction);
 
+        //! Enqueues a collection of one-way SQL operations (can be both adhoc and prepared). The order in which these operations
+        //! were appended to the transaction will be respected during execution.
+        TransactionCallback AsyncCommitTransaction(SQLTransaction<T> transaction);
+
         //! Directly executes a collection of one-way SQL operations (can be both adhoc and prepared). The order in which these operations
         //! were appended to the transaction will be respected during execution.
         void DirectCommitTransaction(SQLTransaction<T>& transaction);
diff --git a/src/server/database/Database/QueryCallback.cpp b/src/server/database/Database/QueryCallback.cpp
index 65b52ff7627..02365a76fe7 100644
--- a/src/server/database/Database/QueryCallback.cpp
+++ b/src/server/database/Database/QueryCallback.cpp
@@ -175,7 +175,7 @@ void QueryCallback::SetNextQuery(QueryCallback&& next)
     MoveFrom(this, std::move(next));
 }
 
-QueryCallback::Status QueryCallback::InvokeIfReady()
+bool QueryCallback::InvokeIfReady()
 {
     QueryCallbackData& callback = _callbacks.front();
     auto checkStateAndReturnCompletion = [this]()
@@ -185,15 +185,15 @@ QueryCallback::Status QueryCallback::InvokeIfReady()
         if (_callbacks.empty())
         {
             ASSERT(!hasNext);
-            return Completed;
+            return true;
         }
 
         // abort chain
         if (!hasNext)
-            return Completed;
+            return true;
 
         ASSERT(_isPrepared == _callbacks.front()._isPrepared);
-        return NextStep;
+        return false;
     };
 
     if (!_isPrepared)
@@ -217,5 +217,5 @@ QueryCallback::Status QueryCallback::InvokeIfReady()
         }
     }
 
-    return NotReady;
+    return false;
 }
diff --git a/src/server/database/Database/QueryCallback.h b/src/server/database/Database/QueryCallback.h
index 1d7e835e999..6cc315964b7 100644
--- a/src/server/database/Database/QueryCallback.h
+++ b/src/server/database/Database/QueryCallback.h
@@ -44,14 +44,8 @@ public:
     // Moves std::future from next to this object
     void SetNextQuery(QueryCallback&& next);
 
-    enum Status
-    {
-        NotReady,
-        NextStep,
-        Completed
-    };
-
-    Status InvokeIfReady();
+    // returns true when completed
+    bool InvokeIfReady();
 
 private:
     QueryCallback(QueryCallback const& right) = delete;
diff --git a/src/server/database/Database/QueryCallbackProcessor.cpp b/src/server/database/Database/QueryCallbackProcessor.cpp
deleted file mode 100644
index 546a6d17c04..00000000000
--- a/src/server/database/Database/QueryCallbackProcessor.cpp
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include "QueryCallbackProcessor.h"
-#include "QueryCallback.h"
-#include <algorithm>
-
-QueryCallbackProcessor::QueryCallbackProcessor()
-{
-}
-
-QueryCallbackProcessor::~QueryCallbackProcessor()
-{
-}
-
-void QueryCallbackProcessor::AddQuery(QueryCallback&& query)
-{
-    _callbacks.emplace_back(std::move(query));
-}
-
-void QueryCallbackProcessor::ProcessReadyQueries()
-{
-    if (_callbacks.empty())
-        return;
-
-    std::vector<QueryCallback> updateCallbacks{ std::move(_callbacks) };
-
-    updateCallbacks.erase(std::remove_if(updateCallbacks.begin(), updateCallbacks.end(), [](QueryCallback& callback)
-    {
-        return callback.InvokeIfReady() == QueryCallback::Completed;
-    }), updateCallbacks.end());
-
-    _callbacks.insert(_callbacks.end(), std::make_move_iterator(updateCallbacks.begin()), std::make_move_iterator(updateCallbacks.end()));
-}
diff --git a/src/server/database/Database/QueryCallbackProcessor.h b/src/server/database/Database/QueryCallbackProcessor.h
deleted file mode 100644
index 85596e90092..00000000000
--- a/src/server/database/Database/QueryCallbackProcessor.h
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef QueryCallbackProcessor_h__
-#define QueryCallbackProcessor_h__
-
-#include "Define.h"
-#include <vector>
-
-class QueryCallback;
-
-class TC_DATABASE_API QueryCallbackProcessor
-{
-public:
-    QueryCallbackProcessor();
-    ~QueryCallbackProcessor();
-
-    void AddQuery(QueryCallback&& query);
-    void ProcessReadyQueries();
-
-private:
-    QueryCallbackProcessor(QueryCallbackProcessor const&) = delete;
-    QueryCallbackProcessor& operator=(QueryCallbackProcessor const&) = delete;
-
-    std::vector<QueryCallback> _callbacks;
-};
-
-#endif // QueryCallbackProcessor_h__
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;
 }
diff --git a/src/server/database/Database/Transaction.h b/src/server/database/Database/Transaction.h
index b11f94ce14e..205b06908fd 100644
--- a/src/server/database/Database/Transaction.h
+++ b/src/server/database/Database/Transaction.h
@@ -22,6 +22,7 @@
 #include "DatabaseEnvFwd.h"
 #include "SQLOperation.h"
 #include "StringFormat.h"
+#include <functional>
 #include <mutex>
 #include <vector>
 
@@ -72,6 +73,7 @@ class TC_DATABASE_API TransactionTask : public SQLOperation
 {
     template <class T> friend class DatabaseWorkerPool;
     friend class DatabaseWorker;
+    friend class TransactionCallback;
 
     public:
         TransactionTask(std::shared_ptr<TransactionBase> trans) : m_trans(trans) { }
@@ -79,9 +81,43 @@ class TC_DATABASE_API TransactionTask : public SQLOperation
 
     protected:
         bool Execute() override;
+        int TryExecute();
+        void CleanupOnFailure();
 
         std::shared_ptr<TransactionBase> m_trans;
         static std::mutex _deadlockLock;
 };
 
+class TC_DATABASE_API TransactionWithResultTask : public TransactionTask
+{
+public:
+    TransactionWithResultTask(std::shared_ptr<TransactionBase> trans) : TransactionTask(trans) { }
+
+    TransactionFuture GetFuture() { return m_result.get_future(); }
+
+protected:
+    bool Execute() override;
+
+    TransactionPromise m_result;
+};
+
+class TC_DATABASE_API TransactionCallback
+{
+public:
+    TransactionCallback(TransactionFuture&& future) : m_future(std::move(future)) { }
+    TransactionCallback(TransactionCallback&&) = default;
+
+    TransactionCallback& operator=(TransactionCallback&&) = default;
+
+    void AfterComplete(std::function<void(bool)> callback) &
+    {
+        m_callback = std::move(callback);
+    }
+
+    bool InvokeIfReady();
+
+    TransactionFuture m_future;
+    std::function<void(bool)> m_callback;
+};
+
 #endif
diff --git a/src/server/game/Entities/Player/Player.cpp b/src/server/game/Entities/Player/Player.cpp
index 806ffb49c07..a9ef1c5d157 100644
--- a/src/server/game/Entities/Player/Player.cpp
+++ b/src/server/game/Entities/Player/Player.cpp
@@ -19319,6 +19319,15 @@ bool Player::_LoadHomeBind(PreparedQueryResult result)
 
 void Player::SaveToDB(bool create /*=false*/)
 {
+    CharacterDatabaseTransaction trans = CharacterDatabase.BeginTransaction();
+
+    SaveToDB(trans, create);
+
+    CharacterDatabase.CommitTransaction(trans);
+}
+
+void Player::SaveToDB(CharacterDatabaseTransaction trans, bool create /* = false */)
+{
     // delay auto save at any saves (manual, in code, or autosave)
     m_nextSave = sWorld->getIntConfig(CONFIG_INTERVAL_SAVE);
 
@@ -19338,7 +19347,6 @@ void Player::SaveToDB(bool create /*=false*/)
     if (!create)
         sScriptMgr->OnPlayerSave(this);
 
-    CharacterDatabaseTransaction trans = CharacterDatabase.BeginTransaction();
     CharacterDatabasePreparedStatement* stmt = nullptr;
     uint8 index = 0;
 
@@ -19630,8 +19638,6 @@ void Player::SaveToDB(bool create /*=false*/)
     if (m_session->isLogingOut() || !sWorld->getBoolConfig(CONFIG_STATS_SAVE_ONLY_ON_LOGOUT))
         _SaveStats(trans);
 
-    CharacterDatabase.CommitTransaction(trans);
-
     // save pet (hunter pet level and experience and all type pets health/mana).
     if (Pet* pet = GetPet())
         pet->SavePetToDB(PET_SAVE_AS_CURRENT);
@@ -26196,7 +26202,7 @@ void Player::ActivateSpec(uint8 spec)
         stmt->setUInt8(1, m_activeSpec);
 
         WorldSession* mySess = GetSession();
-        mySess->GetQueryProcessor().AddQuery(CharacterDatabase.AsyncQuery(stmt)
+        mySess->GetQueryProcessor().AddCallback(CharacterDatabase.AsyncQuery(stmt)
             .WithPreparedCallback([mySess](PreparedQueryResult result)
         {
             // safe callback, we can't pass this pointer directly
diff --git a/src/server/game/Entities/Player/Player.h b/src/server/game/Entities/Player/Player.h
index 97835fb8712..9fc1281158d 100644
--- a/src/server/game/Entities/Player/Player.h
+++ b/src/server/game/Entities/Player/Player.h
@@ -1333,6 +1333,7 @@ class TC_GAME_API Player : public Unit, public GridObject<Player>
         /*********************************************************/
 
         void SaveToDB(bool create = false);
+        void SaveToDB(CharacterDatabaseTransaction trans, bool create = false);
         void SaveInventoryAndGoldToDB(CharacterDatabaseTransaction& trans);                    // fast save function for item/money cheating preventing
         void SaveGoldToDB(CharacterDatabaseTransaction& trans) const;
 
diff --git a/src/server/game/Handlers/CharacterHandler.cpp b/src/server/game/Handlers/CharacterHandler.cpp
index 7744301eb98..81e107f2db3 100644
--- a/src/server/game/Handlers/CharacterHandler.cpp
+++ b/src/server/game/Handlers/CharacterHandler.cpp
@@ -265,7 +265,7 @@ void WorldSession::HandleCharEnumOpcode(WorldPacket& /*recvData*/)
     stmt->setUInt8(0, PET_SAVE_AS_CURRENT);
     stmt->setUInt32(1, GetAccountId());
 
-    _queryProcessor.AddQuery(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSession::HandleCharEnum, this, std::placeholders::_1)));
+    _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSession::HandleCharEnum, this, std::placeholders::_1)));
 }
 
 void WorldSession::HandleCharCreateOpcode(WorldPacket& recvData)
@@ -408,7 +408,7 @@ void WorldSession::HandleCharCreateOpcode(WorldPacket& recvData)
     CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_SEL_CHECK_NAME);
     stmt->setString(0, createInfo->Name);
 
-    _queryProcessor.AddQuery(CharacterDatabase.AsyncQuery(stmt)
+    _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt)
         .WithChainingPreparedCallback([this](QueryCallback& queryCallback, PreparedQueryResult result)
     {
         if (result)
@@ -563,29 +563,31 @@ void WorldSession::HandleCharCreateOpcode(WorldPacket& recvData)
                 return;
             }
 
-            Player newChar(this);
-            newChar.GetMotionMaster()->Initialize();
-            if (!newChar.Create(sObjectMgr->GetGenerator<HighGuid::Player>().Generate(), createInfo.get()))
-
+            std::shared_ptr<Player> newChar(new Player(this), [](Player* ptr)
+            {
+                ptr->CleanupsBeforeDelete();
+                delete ptr;
+            });
+            newChar->GetMotionMaster()->Initialize();
+            if (!newChar->Create(sObjectMgr->GetGenerator<HighGuid::Player>().Generate(), createInfo.get()))
             {
                 // Player not create (race/class/etc problem?)
-                newChar.CleanupsBeforeDelete();
-
                 SendCharCreate(CHAR_CREATE_ERROR);
                 return;
             }
 
             if ((haveSameRace && skipCinematics == 1) || skipCinematics == 2)
-                newChar.setCinematic(1);                          // not show intro
+                newChar->setCinematic(1);                         // not show intro
 
-            newChar.SetAtLoginFlag(AT_LOGIN_FIRST);               // First login
+            newChar->SetAtLoginFlag(AT_LOGIN_FIRST);              // First login
+
+            CharacterDatabaseTransaction characterTransaction = CharacterDatabase.BeginTransaction();
+            LoginDatabaseTransaction trans = LoginDatabase.BeginTransaction();
 
                                                                   // Player created, save it now
-            newChar.SaveToDB(true);
+            newChar->SaveToDB(characterTransaction, true);
             createInfo->CharCount += 1;
 
-            LoginDatabaseTransaction trans = LoginDatabase.BeginTransaction();
-
             LoginDatabasePreparedStatement* stmt = LoginDatabase.GetPreparedStatement(LOGIN_DEL_REALM_CHARACTERS_BY_REALM);
             stmt->setUInt32(0, GetAccountId());
             stmt->setUInt32(1, realm.Id.Realm);
@@ -599,13 +601,19 @@ void WorldSession::HandleCharCreateOpcode(WorldPacket& recvData)
 
             LoginDatabase.CommitTransaction(trans);
 
-            SendCharCreate(CHAR_CREATE_SUCCESS);
-
-            TC_LOG_INFO("entities.player.character", "Account: %d (IP: %s) Create Character:[%s] %s", GetAccountId(), GetRemoteAddress().c_str(), createInfo->Name.c_str(), newChar.GetGUID().ToString().c_str());
-            sScriptMgr->OnPlayerCreate(&newChar);
-            sCharacterCache->AddCharacterCacheEntry(newChar.GetGUID(), GetAccountId(), newChar.GetName(), newChar.GetNativeGender(), newChar.GetRace(), newChar.GetClass(), newChar.GetLevel());
+            AddTransactionCallback(CharacterDatabase.AsyncCommitTransaction(characterTransaction)).AfterComplete([this, newChar = std::move(newChar)](bool success)
+            {
+                if (success)
+                {
+                    TC_LOG_INFO("entities.player.character", "Account: %u (IP: %s) Create Character: %s %s", GetAccountId(), GetRemoteAddress().c_str(), newChar->GetName().c_str(), newChar->GetGUID().ToString().c_str());
+                    sScriptMgr->OnPlayerCreate(newChar.get());
+                    sCharacterCache->AddCharacterCacheEntry(newChar->GetGUID(), GetAccountId(), newChar->GetName(), newChar->GetNativeGender(), newChar->GetRace(), newChar->GetClass(), newChar->GetLevel());
 
-            newChar.CleanupsBeforeDelete();
+                    SendCharCreate(CHAR_CREATE_SUCCESS);
+                }
+                else
+                    SendCharCreate(CHAR_CREATE_ERROR);
+            });
         };
 
         if (allowTwoSideAccounts && !skipCinematics && createInfo->Class != CLASS_DEATH_KNIGHT)
@@ -1135,7 +1143,7 @@ void WorldSession::HandleCharRenameOpcode(WorldPacket& recvData)
     stmt->setUInt32(1, GetAccountId());
     stmt->setString(2, renameInfo->Name);
 
-    _queryProcessor.AddQuery(CharacterDatabase.AsyncQuery(stmt)
+    _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt)
         .WithPreparedCallback(std::bind(&WorldSession::HandleCharRenameCallBack, this, renameInfo, std::placeholders::_1)));
 }
 
@@ -1376,7 +1384,7 @@ void WorldSession::HandleCharCustomize(WorldPacket& recvData)
     CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_SEL_CHAR_CUSTOMIZE_INFO);
     stmt->setUInt32(0, customizeInfo->Guid.GetCounter());
 
-    _queryProcessor.AddQuery(CharacterDatabase.AsyncQuery(stmt)
+    _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt)
         .WithPreparedCallback(std::bind(&WorldSession::HandleCharCustomizeCallback, this, customizeInfo, std::placeholders::_1)));
 }
 
@@ -1632,7 +1640,7 @@ void WorldSession::HandleCharFactionOrRaceChange(WorldPacket& recvData)
     CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_SEL_CHAR_RACE_OR_FACTION_CHANGE_INFOS);
     stmt->setUInt32(0, factionChangeInfo->Guid.GetCounter());
 
-    _queryProcessor.AddQuery(CharacterDatabase.AsyncQuery(stmt)
+    _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt)
         .WithPreparedCallback(std::bind(&WorldSession::HandleCharFactionOrRaceChangeCallback, this, factionChangeInfo, std::placeholders::_1)));
 }
 
diff --git a/src/server/game/Handlers/NPCHandler.cpp b/src/server/game/Handlers/NPCHandler.cpp
index 1078de17111..f25efb18b70 100644
--- a/src/server/game/Handlers/NPCHandler.cpp
+++ b/src/server/game/Handlers/NPCHandler.cpp
@@ -308,7 +308,7 @@ void WorldSession::SendStablePet(ObjectGuid guid)
     stmt->setUInt8(1, PET_SAVE_FIRST_STABLE_SLOT);
     stmt->setUInt8(2, PET_SAVE_LAST_STABLE_SLOT);
 
-    _queryProcessor.AddQuery(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSession::SendStablePetCallback, this, guid, std::placeholders::_1)));
+    _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSession::SendStablePetCallback, this, guid, std::placeholders::_1)));
 }
 
 void WorldSession::SendStablePetCallback(ObjectGuid guid, PreparedQueryResult result)
@@ -409,7 +409,7 @@ void WorldSession::HandleStablePet(WorldPacket& recvData)
     stmt->setUInt8(1, PET_SAVE_FIRST_STABLE_SLOT);
     stmt->setUInt8(2, PET_SAVE_LAST_STABLE_SLOT);
 
-    _queryProcessor.AddQuery(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSession::HandleStablePetCallback, this, std::placeholders::_1)));
+    _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSession::HandleStablePetCallback, this, std::placeholders::_1)));
 }
 
 void WorldSession::HandleStablePetCallback(PreparedQueryResult result)
@@ -471,7 +471,7 @@ void WorldSession::HandleUnstablePet(WorldPacket& recvData)
     stmt->setUInt8(2, PET_SAVE_FIRST_STABLE_SLOT);
     stmt->setUInt8(3, PET_SAVE_LAST_STABLE_SLOT);
 
-    _queryProcessor.AddQuery(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSession::HandleUnstablePetCallback, this, petnumber, std::placeholders::_1)));
+    _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSession::HandleUnstablePetCallback, this, petnumber, std::placeholders::_1)));
 }
 
 void WorldSession::HandleUnstablePetCallback(uint32 petId, PreparedQueryResult result)
@@ -597,7 +597,7 @@ void WorldSession::HandleStableSwapPet(WorldPacket& recvData)
     stmt->setUInt32(0, _player->GetGUID().GetCounter());
     stmt->setUInt32(1, petId);
 
-    _queryProcessor.AddQuery(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSession::HandleStableSwapPetCallback, this, petId, std::placeholders::_1)));
+    _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSession::HandleStableSwapPetCallback, this, petId, std::placeholders::_1)));
 }
 
 void WorldSession::HandleStableSwapPetCallback(uint32 petId, PreparedQueryResult result)
diff --git a/src/server/game/Handlers/SpellHandler.cpp b/src/server/game/Handlers/SpellHandler.cpp
index fc62887894a..740f4144d3b 100644
--- a/src/server/game/Handlers/SpellHandler.cpp
+++ b/src/server/game/Handlers/SpellHandler.cpp
@@ -241,7 +241,7 @@ void WorldSession::HandleOpenItemOpcode(WorldPacket& recvPacket)
     {
         CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_SEL_CHARACTER_GIFT_BY_ITEM);
         stmt->setUInt32(0, item->GetGUID().GetCounter());
-        _queryProcessor.AddQuery(CharacterDatabase.AsyncQuery(stmt)
+        _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt)
             .WithPreparedCallback(std::bind(&WorldSession::HandleOpenWrappedItemCallback, this, item->GetPos(), item->GetGUID(), std::placeholders::_1)));
     }
     else
diff --git a/src/server/game/Server/WorldSession.cpp b/src/server/game/Server/WorldSession.cpp
index 55282e1a7bb..256e818de5f 100644
--- a/src/server/game/Server/WorldSession.cpp
+++ b/src/server/game/Server/WorldSession.cpp
@@ -1193,7 +1193,8 @@ void WorldSession::SetPlayer(Player* player)
 
 void WorldSession::ProcessQueryCallbacks()
 {
-    _queryProcessor.ProcessReadyQueries();
+    _queryProcessor.ProcessReadyCallbacks();
+    _transactionCallbacks.ProcessReadyCallbacks();
 
     if (_realmAccountLoginCallback.valid() && _realmAccountLoginCallback.wait_for(std::chrono::seconds(0)) == std::future_status::ready)
         InitializeSessionCallback(static_cast<CharacterDatabaseQueryHolder*>(_realmAccountLoginCallback.get()));
@@ -1203,6 +1204,11 @@ void WorldSession::ProcessQueryCallbacks()
         HandlePlayerLogin(reinterpret_cast<LoginQueryHolder*>(_charLoginCallback.get()));
 }
 
+TransactionCallback& WorldSession::AddTransactionCallback(TransactionCallback&& callback)
+{
+    return _transactionCallbacks.AddCallback(std::move(callback));
+}
+
 void WorldSession::InitWarden(BigNumber* k, std::string const& os)
 {
     if (os == "Win")
diff --git a/src/server/game/Server/WorldSession.h b/src/server/game/Server/WorldSession.h
index 57794ac81bf..b9df671a502 100644
--- a/src/server/game/Server/WorldSession.h
+++ b/src/server/game/Server/WorldSession.h
@@ -23,11 +23,11 @@
 #define __WORLDSESSION_H
 
 #include "Common.h"
+#include "AsyncCallbackProcessor.h"
 #include "DatabaseEnvFwd.h"
 #include "LockedQueue.h"
 #include "ObjectGuid.h"
 #include "Packet.h"
-#include "QueryCallbackProcessor.h"
 #include "SharedDefines.h"
 #include <string>
 #include <map>
@@ -1091,6 +1091,7 @@ class TC_GAME_API WorldSession
 
     public:
         QueryCallbackProcessor& GetQueryProcessor() { return _queryProcessor; }
+        TransactionCallback& AddTransactionCallback(TransactionCallback&& callback);
 
     private:
         void ProcessQueryCallbacks();
@@ -1099,6 +1100,7 @@ class TC_GAME_API WorldSession
         QueryResultHolderFuture _charLoginCallback;
 
         QueryCallbackProcessor _queryProcessor;
+        AsyncCallbackProcessor<TransactionCallback> _transactionCallbacks;
 
     friend class World;
     protected:
diff --git a/src/server/game/Server/WorldSocket.cpp b/src/server/game/Server/WorldSocket.cpp
index 0e65704076d..ff85f71c769 100644
--- a/src/server/game/Server/WorldSocket.cpp
+++ b/src/server/game/Server/WorldSocket.cpp
@@ -39,13 +39,15 @@ WorldSocket::WorldSocket(tcp::socket&& socket)
     _headerBuffer.Resize(sizeof(ClientPktHeader));
 }
 
+WorldSocket::~WorldSocket() = default;
+
 void WorldSocket::Start()
 {
     std::string ip_address = GetRemoteIpAddress().to_string();
     LoginDatabasePreparedStatement* stmt = LoginDatabase.GetPreparedStatement(LOGIN_SEL_IP_INFO);
     stmt->setString(0, ip_address);
 
-    _queryProcessor.AddQuery(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSocket::CheckIpCallback, this, std::placeholders::_1)));
+    _queryProcessor.AddCallback(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSocket::CheckIpCallback, this, std::placeholders::_1)));
 }
 
 void WorldSocket::CheckIpCallback(PreparedQueryResult result)
@@ -115,7 +117,7 @@ bool WorldSocket::Update()
     if (!BaseSocket::Update())
         return false;
 
-    _queryProcessor.ProcessReadyQueries();
+    _queryProcessor.ProcessReadyCallbacks();
 
     return true;
 }
@@ -439,7 +441,7 @@ void WorldSocket::HandleAuthSession(WorldPacket& recvPacket)
     stmt->setInt32(0, int32(realm.Id.Realm));
     stmt->setString(1, authSession->Account);
 
-    _queryProcessor.AddQuery(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSocket::HandleAuthSessionCallback, this, authSession, std::placeholders::_1)));
+    _queryProcessor.AddCallback(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSocket::HandleAuthSessionCallback, this, authSession, std::placeholders::_1)));
 }
 
 void WorldSocket::HandleAuthSessionCallback(std::shared_ptr<AuthSession> authSession, PreparedQueryResult result)
@@ -600,7 +602,7 @@ void WorldSocket::HandleAuthSessionCallback(std::shared_ptr<AuthSession> authSes
     if (wardenActive)
         _worldSession->InitWarden(&account.SessionKey, account.OS);
 
-    _queryProcessor.AddQuery(_worldSession->LoadPermissionsAsync().WithPreparedCallback(std::bind(&WorldSocket::LoadSessionPermissionsCallback, this, std::placeholders::_1)));
+    _queryProcessor.AddCallback(_worldSession->LoadPermissionsAsync().WithPreparedCallback(std::bind(&WorldSocket::LoadSessionPermissionsCallback, this, std::placeholders::_1)));
     AsyncRead();
 }
 
diff --git a/src/server/game/Server/WorldSocket.h b/src/server/game/Server/WorldSocket.h
index 6f6b0848423..00d2ec59651 100644
--- a/src/server/game/Server/WorldSocket.h
+++ b/src/server/game/Server/WorldSocket.h
@@ -71,6 +71,7 @@ class TC_GAME_API WorldSocket : public Socket<WorldSocket>
 
 public:
     WorldSocket(tcp::socket&& socket);
+    ~WorldSocket();
 
     WorldSocket(WorldSocket const& right) = delete;
     WorldSocket& operator=(WorldSocket const& right) = delete;
diff --git a/src/server/game/World/World.cpp b/src/server/game/World/World.cpp
index 93f1b919dab..34864e46779 100644
--- a/src/server/game/World/World.cpp
+++ b/src/server/game/World/World.cpp
@@ -3120,7 +3120,7 @@ void World::UpdateRealmCharCount(uint32 accountId)
 {
     CharacterDatabasePreparedStatement* stmt = CharacterDatabase.GetPreparedStatement(CHAR_SEL_CHARACTER_COUNT);
     stmt->setUInt32(0, accountId);
-    _queryProcessor.AddQuery(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&World::_UpdateRealmCharCount, this, std::placeholders::_1)));
+    _queryProcessor.AddCallback(CharacterDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&World::_UpdateRealmCharCount, this, std::placeholders::_1)));
 }
 
 void World::_UpdateRealmCharCount(PreparedQueryResult resultCharCount)
@@ -3492,7 +3492,7 @@ uint64 World::getWorldState(uint32 index) const
 
 void World::ProcessQueryCallbacks()
 {
-    _queryProcessor.ProcessReadyQueries();
+    _queryProcessor.ProcessReadyCallbacks();
 }
 
 void World::ReloadRBAC()
diff --git a/src/server/game/World/World.h b/src/server/game/World/World.h
index 24338a7eee3..98c3df02ba7 100644
--- a/src/server/game/World/World.h
+++ b/src/server/game/World/World.h
@@ -23,10 +23,10 @@
 #define __WORLD_H
 
 #include "Common.h"
+#include "AsyncCallbackProcessor.h"
 #include "DatabaseEnvFwd.h"
 #include "LockedQueue.h"
 #include "ObjectGuid.h"
-#include "QueryCallbackProcessor.h"
 #include "SharedDefines.h"
 #include "Timer.h"