/*
   Copyright (c) 2013, 2024, 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 <stddef.h>

#include "mysql/psi/mysql_socket.h"
#include "mysql/psi/mysql_thread.h"
#include "mysql_com.h"
#include "mysqld_error.h"                   // ER_*
#include "sql/conn_handler/channel_info.h"  // Channel_info
#include "sql/conn_handler/connection_handler_impl.h"
#include "sql/conn_handler/connection_handler_manager.h"  // Connection_handler_manager
#include "sql/mysqld.h"              // connection_errors_internal
#include "sql/mysqld_thd_manager.h"  // Global_THD_manager
#include "sql/protocol_classic.h"
#include "sql/sql_class.h"             // THD
#include "sql/sql_connect.h"           // close_connection
#include "sql/sql_parse.h"             // do_command
#include "sql/sql_thd_internal_api.h"  // thd_set_thread_stack

bool One_thread_connection_handler::add_connection(Channel_info *channel_info) {
  if (my_thread_init()) {
    connection_errors_internal++;
    channel_info->send_error_and_close_channel(ER_OUT_OF_RESOURCES, 0, false);
    Connection_handler_manager::dec_connection_count();
    return true;
  }

  THD *thd = channel_info->create_thd();
  if (thd == nullptr) {
    connection_errors_internal++;
    channel_info->send_error_and_close_channel(ER_OUT_OF_RESOURCES, 0, false);
    Connection_handler_manager::dec_connection_count();
    return true;
  }

  thd->set_new_thread_id();

  /*
    handle_one_connection() is normally the only way a thread would
    start and would always be on the very high end of the stack ,
    therefore, the thread stack always starts at the address of the
    first local variable of handle_one_connection, which is thd. We
    need to know the start of the stack so that we could check for
    stack overruns.
  */
  thd_set_thread_stack(thd, (char *)&thd);
  thd->store_globals();

  mysql_thread_set_psi_id(thd->thread_id());
  mysql_socket_set_thread_owner(
      thd->get_protocol_classic()->get_vio()->mysql_socket);

  Global_THD_manager *thd_manager = Global_THD_manager::get_instance();
  thd_manager->add_thd(thd);

  bool error = false;
  if (thd_prepare_connection(thd))
    error = true;  // Returning true causes inc_aborted_connects() to be called.
  else {
    delete channel_info;
    while (thd_connection_alive(thd)) {
      if (do_command(thd)) break;
    }
    end_connection(thd);
  }
  close_connection(thd, 0, false, false);
  thd->release_resources();
  thd_manager->remove_thd(thd);
  Connection_handler_manager::dec_connection_count();
  delete thd;
  return error;
}