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Re: Rev 4056: MDEV-5616 - Deadlock between CREATE/DROP FUNCTION and SELECT from view
Ok to push.
A couple of comments below.
On Feb 07, Sergey Vojtovich wrote:
> revno: 4056
> revision-id: svoj@xxxxxxxxxxx-20140207100451-8pnzn85pjjwvwfs4
> parent: elenst@xxxxxxxxxxxxxx-20140205102537-7ern5gfca6a6ojg3
> committer: Sergey Vojtovich <svoj@xxxxxxxxxxx>
> branch nick: 5.5-mdev5616
> timestamp: Fri 2014-02-07 14:04:51 +0400
> MDEV-5616 - Deadlock between CREATE/DROP FUNCTION and SELECT from view
> Deadlock happened due to mixed lock order.
> CREATE/DROP function: wrlock(THR_LOCK_udf) -> lock(LOCK_open)
> SELECT from view: lock(LOCK_open) -> rdlock(THR_LOCK_udf)
> Fixed CREATE/DROP function so that LOCK_open does not intersect with
> 10.0 is not affected: it doesn't hold LOCK_open while opening view.
I'm pretty sure it'll auto-merge and nobody will remember this warning
at that time. So this patch will be in 10.0.
Perhaps you should add
#if MYSQL_VERSION_ID > 50600
#error don't merge into 10.0
Or, may be, it's not a big deal to have it in 10.0...
> === modified file 'sql/sql_udf.cc'
> --- a/sql/sql_udf.cc 2012-03-27 23:04:46 +0000
> +++ b/sql/sql_udf.cc 2014-02-07 10:04:51 +0000
> @@ -466,7 +467,11 @@ int mysql_create_function(THD *thd,udf_f
> if ((save_binlog_row_based= thd->is_current_stmt_binlog_format_row()))
> + tables.init_one_table("mysql", 5, "func", 4, "func", TL_WRITE);
I know it's a old line that you've moved and it's a matter of taste
anyway, so up to you, but generally I prefer to see STRING_WITH_LEN
here. It 1) makes a certain class of typos impossible; 2) documents the
code, one doesn't need to think what these 4 and 5 stand for.