Drizzled Public API Documentation

unlock_tables.cc
00001 /* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
00002  *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
00003  *
00004  *  Copyright (C) 2009 Sun Microsystems, Inc.
00005  *
00006  *  This program is free software; you can redistribute it and/or modify
00007  *  it under the terms of the GNU General Public License as published by
00008  *  the Free Software Foundation; either version 2 of the License, or
00009  *  (at your option) any later version.
00010  *
00011  *  This program is distributed in the hope that it will be useful,
00012  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  *  GNU General Public License for more details.
00015  *
00016  *  You should have received a copy of the GNU General Public License
00017  *  along with this program; if not, write to the Free Software
00018  *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
00019  */
00020 
00021 #include <config.h>
00022 #include <drizzled/show.h>
00023 #include <drizzled/session.h>
00024 #include <drizzled/lock.h>
00025 #include <drizzled/statement/unlock_tables.h>
00026 
00027 namespace drizzled
00028 {
00029 
00030 bool statement::UnlockTables::execute()
00031 {
00032   /*
00033      It is critical for mysqldump --single-transaction --master-data that
00034      UNLOCK TABLES does not implicitely commit a connection which has only
00035      done FLUSH TABLES WITH READ LOCK + BEGIN. If this assumption becomes
00036      false, mysqldump will not work.
00037    */
00038   if (session().isGlobalReadLock())
00039   {
00040     session().unlockGlobalReadLock();
00041     session().my_ok();
00042   }
00043   else
00044   {
00045     my_error(ER_NO_LOCK_HELD, MYF(0));
00046   }
00047 
00048   return false;
00049 }
00050 
00051 } /* namespace drizzled */
00052