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/*
* This file is part of the AzerothCore 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 Affero General Public License as published by the
* Free Software Foundation; either version 3 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 Affero 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 "Transaction.h"
#include "Errors.h"
#include "Log.h"
#include "MySQLConnection.h"
#include "PreparedStatement.h"
#include "Timer.h"
#include <mysqld_error.h>
#include <sstream>
#include <thread>
std::mutex TransactionTask::_deadlockLock;
constexpr Milliseconds DEADLOCK_MAX_RETRY_TIME_MS = 1min;
//- Append a raw ad-hoc query to the transaction
void TransactionBase::Append(std::string_view sql)
{
SQLElementData data = {};
data.type = SQL_ELEMENT_RAW;
data.element = std::string(sql);
m_queries.emplace_back(data);
}
//- Append a prepared statement to the transaction
void TransactionBase::AppendPreparedStatement(PreparedStatementBase* stmt)
{
SQLElementData data = {};
data.type = SQL_ELEMENT_PREPARED;
data.element = stmt;
m_queries.emplace_back(data);
}
void TransactionBase::Cleanup()
{
// This might be called by explicit calls to Cleanup or by the auto-destructor
if (_cleanedUp)
return;
for (SQLElementData& data : m_queries)
{
switch (data.type)
{
case SQL_ELEMENT_PREPARED:
{
try
{
PreparedStatementBase* stmt = std::get<PreparedStatementBase*>(data.element);
ASSERT(stmt);
delete stmt;
}
catch (const std::bad_variant_access& ex)
{
LOG_FATAL("sql.sql", "> PreparedStatementBase not found in SQLElementData. {}", ex.what());
ABORT();
}
}
break;
case SQL_ELEMENT_RAW:
{
try
{
std::get<std::string>(data.element).clear();
}
catch (const std::bad_variant_access& ex)
{
LOG_FATAL("sql.sql", "> std::string not found in SQLElementData. {}", ex.what());
ABORT();
}
}
break;
}
}
m_queries.clear();
_cleanedUp = true;
}
bool TransactionTask::Execute()
{
int errorCode = TryExecute();
if (!errorCode)
return true;
if (errorCode == ER_LOCK_DEADLOCK)
{
std::ostringstream threadIdStream;
threadIdStream << std::this_thread::get_id();
std::string threadId = threadIdStream.str();
{
// 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);
for (Milliseconds loopDuration{}, startMSTime = GetTimeMS(); loopDuration <= DEADLOCK_MAX_RETRY_TIME_MS; loopDuration = GetMSTimeDiffToNow(startMSTime))
{
if (!TryExecute())
return true;
LOG_WARN("sql.sql", "Deadlocked SQL Transaction, retrying. Loop timer: {} ms, Thread Id: {}", loopDuration.count(), threadId);
}
}
LOG_ERROR("sql.sql", "Fatal deadlocked SQL Transaction, it will not be retried anymore. Thread Id: {}", threadId);
}
// 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)
{
std::ostringstream threadIdStream;
threadIdStream << std::this_thread::get_id();
std::string threadId = threadIdStream.str();
{
// 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);
for (Milliseconds loopDuration{}, startMSTime = GetTimeMS(); loopDuration <= DEADLOCK_MAX_RETRY_TIME_MS; loopDuration = GetMSTimeDiffToNow(startMSTime))
{
if (!TryExecute())
{
m_result.set_value(true);
return true;
}
LOG_WARN("sql.sql", "Deadlocked SQL Transaction, retrying. Loop timer: {} ms, Thread Id: {}", loopDuration.count(), threadId);
}
}
LOG_ERROR("sql.sql", "Fatal deadlocked SQL Transaction, it will not be retried anymore. Thread Id: {}", threadId);
}
// Clean up now.
CleanupOnFailure();
m_result.set_value(false);
return false;
}
bool TransactionCallback::InvokeIfReady()
{
if (m_future.valid() && m_future.wait_for(0s) == std::future_status::ready)
{
m_callback(m_future.get());
return true;
}
return false;
}
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