Re: Race conditions, race conditions!

On Sat, May 07, 2005 at 07:20:48PM -0400, Tom Lane wrote:
> Greg Stark <gsstark@mit.edu> writes:
> > I wonder if there's an argument for building assertion-enabled builds with
> > code that randomly yields the processor some percentage of time before and
> > after taking a lock. It wouldn't catch every case but it might help.
> 
> Seems like that would mainly help you find cases where you'd put a lock
> acquire or release a bit too late or too soon in a sequence of events;
> not cases where you'd failed to acquire a needed lock at all.  It'd be
> more useful I think to have a facility that randomly stops backends for
> awhile regardless of exactly where they are in the code.
> 
> A high-load test case actually does this to some extent, but the problem
> is you have little reproducibility and no assurance that execution
> stopped for long enough to let critical events happen elsewhere.  The
> ideal facility I think would slow one backend much more than others,
> whereas high load still leaves them all making progress at about the
> same rate ...

Would setting different priorities/niceness on different backends during
the stress test help? It might not be perfect but it should be trivial
to accomplish...
-- 
Jim C. Nasby, Database Consultant               decibel@decibel.org 
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