session_guard.h

Go to the documentation of this file.

// Copyright (c) 2026, Oracle and/or its affiliates.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License, version 2.0,
// as published by the Free Software Foundation.
//
// This program is designed to work with certain software (including
// but not limited to OpenSSL) that is licensed under separate terms,
// as designated in a particular file or component or in included license
// documentation.  The authors of MySQL hereby grant you an additional
// permission to link the program and your derivative works with the
// separately licensed software that they have either included with
// the program or referenced in the documentation.
//
// 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, version 2.0, for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA.
 
#include "sql/sql_class.h"
 
#ifndef MYSQL_CSA_SESSION_GUARD_H
#define MYSQL_CSA_SESSION_GUARD_H
 
namespace mysql::csa {
 
/// @brief RAII guard for temporarily switching current_thd to a session THD.
/// Saves the original current_thd in ctor and restores it in dtor.
struct Session_guard {
  /// @brief Constructor: saves original current_thd and sets to the given thd.
  Session_guard(THD *thd) {
    m_orig_thd = current_thd;
    current_thd = thd;
  }
 
  /// @brief Destructor: restores the original current_thd.
  ~Session_guard() { current_thd = m_orig_thd; }
 
 private:
  THD *m_orig_thd{nullptr};
};
 
}  // namespace mysql::csa
 
#endif  // MYSQL_CSA_SESSION_GUARD_H