fix(Core/Shared/DB): recommit transactions on dead-lock error (#6069)

src/server/database/Database/DatabaseWorkerPool.cpp

@@ -7,6 +7,8 @@
 #include "DatabaseWorkerPool.h"
 #include "DatabaseEnv.h"
 
+#include <mysqld_error.h>
+
 #define MIN_MYSQL_SERVER_VERSION 50700u
 #define MIN_MYSQL_CLIENT_VERSION 50700u
 
@@ -318,7 +320,8 @@ template <class T>
 void DatabaseWorkerPool<T>::DirectCommitTransaction(SQLTransaction& transaction)
 {
     T* con = GetFreeConnection();
-    if (con->ExecuteTransaction(transaction))
+    int errorCode = con->ExecuteTransaction(transaction);
+    if (!errorCode)
     {
         con->Unlock();      // OK, operation succesful
         return;
@@ -326,12 +329,12 @@ void DatabaseWorkerPool<T>::DirectCommitTransaction(SQLTransaction& transaction)
 
     //! Handle MySQL Errno 1213 without extending deadlock to the core itself
     //! TODO: More elegant way
-    if (con->GetLastError() == 1213)
+    if (errorCode == ER_LOCK_DEADLOCK)
     {
         uint8 loopBreaker = 5;
         for (uint8 i = 0; i < loopBreaker; ++i)
         {
-            if (con->ExecuteTransaction(transaction))
+            if (!con->ExecuteTransaction(transaction))
                 break;
         }
     }

src/server/database/Database/MySQLConnection.cpp

@@ -355,11 +355,11 @@ void MySQLConnection::CommitTransaction()
     Execute("COMMIT");
 }
 
-bool MySQLConnection::ExecuteTransaction(SQLTransaction& transaction)
+int MySQLConnection::ExecuteTransaction(SQLTransaction& transaction)
 {
     std::list<SQLElementData> const& queries = transaction->m_queries;
     if (queries.empty())
-        return false;
+        return -1;
 
     BeginTransaction();
 
@@ -376,8 +376,9 @@ bool MySQLConnection::ExecuteTransaction(SQLTransaction& transaction)
                 if (!Execute(stmt))
                 {
                     LOG_INFO("sql.driver", "[Warning] Transaction aborted. %u queries not executed.", (uint32)queries.size());
+                    int errorCode = GetLastError();
                     RollbackTransaction();
-                    return false;
+                    return errorCode;
                 }
             }
             break;
@@ -388,8 +389,9 @@ bool MySQLConnection::ExecuteTransaction(SQLTransaction& transaction)
                 if (!Execute(sql))
                 {
                     LOG_INFO("sql.driver", "[Warning] Transaction aborted. %u queries not executed.", (uint32)queries.size());
+                    int errorCode = GetLastError();
                     RollbackTransaction();
-                    return false;
+                    return errorCode;
                 }
             }
             break;
@@ -402,7 +404,7 @@ bool MySQLConnection::ExecuteTransaction(SQLTransaction& transaction)
     // and not while iterating over every element.
 
     CommitTransaction();
-    return true;
+    return 0;
 }
 
 MySQLPreparedStatement* MySQLConnection::GetPreparedStatement(uint32 index)

src/server/database/Database/MySQLConnection.h

@@ -78,7 +78,7 @@ public:
     void BeginTransaction();
     void RollbackTransaction();
     void CommitTransaction();
-    bool ExecuteTransaction(SQLTransaction& transaction);
+    int ExecuteTransaction(SQLTransaction& transaction);
 
     operator bool () const { return m_Mysql != nullptr; }
     void Ping() { mysql_ping(m_Mysql); }

src/server/database/Database/Transaction.cpp

@@ -7,6 +7,8 @@
 #include "DatabaseEnv.h"
 #include "Transaction.h"
 
+#include <mysqld_error.h>
+
 //- Append a raw ad-hoc query to the transaction
 void Transaction::Append(const char* sql)
 {
@@ -63,14 +65,15 @@ void Transaction::Cleanup()
 
 bool TransactionTask::Execute()
 {
-    if (m_conn->ExecuteTransaction(m_trans))
+    int errorCode = m_conn->ExecuteTransaction(m_trans);
+    if (!errorCode)
         return true;
 
-    if (m_conn->GetLastError() == 1213)
+    if (errorCode == ER_LOCK_DEADLOCK)
     {
         uint8 loopBreaker = 5;  // Handle MySQL Errno 1213 without extending deadlock to the core itself
         for (uint8 i = 0; i < loopBreaker; ++i)
-            if (m_conn->ExecuteTransaction(m_trans))
+            if (!m_conn->ExecuteTransaction(m_trans))
                 return true;
     }