From: Konstantin Osipov
Date: July 20 2007 11:11am
Subject: Re: bk commit into 5.0 tree (gkodinov:1.2536) BUG#29644
List-Archive: http://lists.mysql.com/commits/31222
Message-Id: <20070720111150.GM26969@bodhi>
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* kgeorge@stripped <kgeorge@stripped> [07/07/20 14:28]:

OK to push.

> ChangeSet@stripped, 2007-07-20 13:14:57+03:00, gkodinov@stripped +4 -0
>   Bug #29644: alter table hangs if records locked in share mode 
>   by long running transaction
>   
>   On Windows opened files can't be deleted. There was a special
>   upgraded lock mode (TL_WRITE instead of TL_WRITE_ALLOW_READ) 
>   in ALTER TABLE to remedy make sure nobody has the table opened
                     ^^^^^^^^^^^^

Please proof-read the changeset comments before pushing.

>   when deleting the old table in ALTER TABLE. This special mode
>   was causing ALTER TABLE to hang waiting on a lock inside InnoDB.
>   This special lock is no longer necessary as the server is 
>   closing the tables it needs to delete in ALTER TABLE.
>   Fixed by removing the special lock.
>   Note that this also reverses the fix for bug 17264 that deals with
>   another consequence of this special lock mode being used.
> 
>  --echo End of 5.0 tests
> diff -Nrup a/sql/ha_innodb.cc b/sql/ha_innodb.cc
> --- a/sql/ha_innodb.cc	2007-06-20 19:22:25 +03:00
> +++ b/sql/ha_innodb.cc	2007-07-20 13:14:55 +03:00
> @@ -6702,17 +6702,6 @@ ha_innobase::store_lock(
>  		    && !thd->tablespace_op
>  		    && thd->lex->sql_command != SQLCOM_TRUNCATE
>  		    && thd->lex->sql_command != SQLCOM_OPTIMIZE
> -
> -#ifdef __WIN__
> -                /* For alter table on win32 for succesful operation
> -                completion it is used TL_WRITE(=10) lock instead of
> -                TL_WRITE_ALLOW_READ(=6), however here in innodb handler
> -                TL_WRITE is lifted to TL_WRITE_ALLOW_WRITE, which causes
> -                race condition when several clients do alter table
> -                simultaneously (bug #17264). This fix avoids the problem. */
> -		    && thd->lex->sql_command != SQLCOM_ALTER_TABLE
> -#endif
> -
>  		    && thd->lex->sql_command != SQLCOM_CREATE_TABLE) {
>  
>  			lock_type = TL_WRITE_ALLOW_WRITE;
> diff -Nrup a/sql/sql_base.cc b/sql/sql_base.cc

Don't forget to send this patch to dev-innodb@stripped and
dev@stripped

-- 
-- Konstantin Osipov              Software Developer, Moscow, Russia
-- MySQL AB, www.mysql.com   The best DATABASE COMPANY in the GALAXY