Re: Strange hanging bug in a simple milter

Vesa-Matti, Heikki,

* Heikki Linnakangas (hlinnakangas@vmware.com) wrote:
> On 09.09.2013 15:36, Vesa-Matti J Kari wrote:
> >If I interpret this correctly, threads #2 and #3 are waiting for the same
> >lock but they make no progress.
>
> A-ha, the deadlock happens while doing SSL stuff. I didn't have SSL
> enabled in my test server. As soon as I turned it on, it hung.
>
> Attached is a small stand-alone test program to reproduce it. You
> can pass a libpq connection string as argument to it.

Interesting...  Which version of libpq were you working against?  I see
that Vesa-Matti had the problem happen w/ 9.1.9, which should have been
before the changes that I made to add locking around our usage of
SSL_context, as otherwise we would end up in situations where we'd dump
core, but he also had it with 9.3rc1, which should have included it.  I
had tested the patch w/ a pretty good amount of concurrent threads fired
off from a little python script and didn't run into any deadlocks
there..

Vesa-Matti, was this working previously, and are you sure you were
testing with 9.3rc1's libpq?  Heikki, which are you testing against and
perhaps you might try before and after?  I'll be able to look into it
more in a few hours also.
Thanks,
    Stephen