Possible bug related to stm and exceptions

[Andreas Voellmy]

Hi Carter,

I just tested with HEAD and the problem still happens.




On Wed, Oct 16, 2013 at 10:29 PM, Carter Schonwald <
carter.schonwald at gmail.com> wrote:

> I remember Luite mentioning that when he and Ryan Yates where working out
> STM for GHCJS, that they  had found some bugs in STM in ghc (presumably now
> fixed in head?), have you been able to reproduce the problem in head?
>
> theres also some issues with STM relating to fairness, could you be
> hitting a fairness issue?
>
>
> On Wed, Oct 16, 2013 at 9:01 PM, Andreas Voellmy <
> andreas.voellmy at gmail.com> wrote:
>
>> Hi all,
>>
>> I have a program that uses STM heavily and also performs lots of foreign
>> calls. I've noticed that sometimes the program uses 100% CPU indefinitely
>> and uses lots of memory - I see it go up to about 5GB before I kill it.
>> I've grabbed some preliminary samples of stack traces and see lots stm
>> related stuff (e.g. lots of stg_atomically_frame_info and
>> stmCommitTransaction entries).  I can pretty reliably get the behavior to
>> happen now by closing a socket that my Haskell program is trying to recv
>> from. When this causes an exception to be raised (something like "recv:
>> resource vanished (Connection reset by peer)") , then this behavior gets
>> triggered.  I haven't pinned down the bug yet, but I'm suspecting it is STM
>> related - somehow the exception causes some STM transaction to go wrong.
>>
>> Are there any known bugs that sound similar to this?
>>
>> BTW, this is with GHC 7.6.3 from a recent HP release on OS X.
>>
>> -Andi
>>
>>
>>
>> _______________________________________________
>> ghc-devs mailing list
>> ghc-devs at haskell.org
>> http://www.haskell.org/mailman/listinfo/ghc-devs
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/ghc-devs/attachments/20131017/bbe97e7f/attachment.html>