RE: back-bdb deadlocks

["Howard Chu" <hyc@highlandsun.com>]

I've cleaned things up and recompiled/linked with BDB 4.0.14 (was using 3.3.11)
and the same deadlock occurs in txn_abort. You're right, this sounds like a bug
for Sleepycat to address. I cannot find any code path that bdb_add executes
without a transaction, so it appears we're doing the right things.

  -- Howard Chu
  Chief Architect, Symas Corp.       Director, Highland Sun
  http://www.symas.com               http://highlandsun.com/hyc
  Symas: Premier OpenSource Development and Support

> -----Original Message-----
> From: Lawrence Greenfield [mailto:leg+@andrew.cmu.edu]
> Sent: Wednesday, January 16, 2002 6:13 PM
> To: openldap-devel@OpenLDAP.org; Howard Chu
> Subject: Re: back-bdb deadlocks
>
>
>    From: "Howard Chu" <hyc@highlandsun.com>
>    Date: Wed, 16 Jan 2002 16:40:15 -0800
>
>    I believe a similar solution to this is needed in back-bdb, but I
>    haven't yet spent much time thinking about it can work. The current
>    situation is that back-bdb gets deadlocked very easily by more than
>    2 simultaneous updaters.  There doesn't seem to be any easy
>    solution to this; my debug session with three deadlocked threads
>    showed that two of them were deadlocked in txn_abort - i.e.,
>    deadlock detection already did it's job, but new locks were still
>    needed to unravel the transaction. Pretty rude. (I suspect this
>
> If this is happening and OpenLDAP is playing by Berkeley db's rules,
> there is a bug in Berkeley db and it should be reported to Sleepycat.
> I've never seen something like that happen in my testing, though I
> very rarely play with multithreaded programs.
>
> Larry
>