~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2009 Sun Microsystems

 *

 *  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, write to the Free Software

 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#include "config.h"

#include <drizzled/show.h>

#include <drizzled/session.h>

#include <drizzled/lock.h>

#include <drizzled/statement/drop_table.h>

#include "drizzled/sql_table.h"

namespace drizzled

{

/*

 delete (drop) tables.

  SYNOPSIS

   mysql_rm_table()

   session			Thread handle

   tables		List of tables to delete

   if_exists		If 1, don't give error if one table doesn't exists

  NOTES

    Will delete all tables that can be deleted and give a compact error

    messages for tables that could not be deleted.

    If a table is in use, we will wait for all users to free the table

    before dropping it

    Wait if global_read_lock (FLUSH TABLES WITH READ LOCK) is set, but

    not if under LOCK TABLES.

  RETURN

    false OK.  In this case ok packet is sent to user

    true  Error

*/

static bool mysql_rm_table(Session *session, TableList *tables, bool if_exists, bool drop_temporary)

{

  bool error, need_start_waiting= false;

  /* mark for close and remove all cached entries */

  if (not drop_temporary)

  {

    if (not (need_start_waiting= !wait_if_global_read_lock(session, false, true)))

      return true;

  }

  /*

    Acquire LOCK_open after wait_if_global_read_lock(). If we would hold

    LOCK_open during wait_if_global_read_lock(), other threads could not

    close their tables. This would make a pretty deadlock.

  */

  error= mysql_rm_table_part2(session, tables, if_exists, drop_temporary);

  if (need_start_waiting)

    start_waiting_global_read_lock(session);

  if (error)

    return true;

  session->my_ok();

  return false;

}

bool statement::DropTable::execute()

{

  TableList *first_table= (TableList *) session->lex->select_lex.table_list.first;

  TableList *all_tables= session->lex->query_tables;

  assert(first_table == all_tables && first_table != 0);

  if (not drop_temporary)

  {

    if (not session->endActiveTransaction())

    {

      return true;

    }

  }

  /* DDL and binlog write order protected by LOCK_open */

  bool res= mysql_rm_table(session,

                           first_table,

                           drop_if_exists,

                           drop_temporary);

  return res;

}

} /* namespace drizzled */