On Wed, Jan 24, 2018 at 5:25 PM, Thomas Munro
<thomas.munro@enterprisedb.com> wrote:
> If there were some way for the postmaster to cause reason
> PROCSIG_PARALLEL_MESSAGE to be set in the leader process instead of
> just notification via kill(SIGUSR1) when it fails to fork a parallel
> worker, we'd get (1) for free in any latch/CFI loop code. But I
> understand that we can't do that by project edict.
Based on the above observation, here is a terrible idea you'll all
hate. It is pessimistic and expensive: it thinks that every latch
wake might be the postmaster telling us it's failed to fork() a
parallel worker, until we've seen a sign of life on every worker's
error queue. Untested illustration code only. This is the only way
I've come up with to discover fork failure in any latch/CFI loop (ie
without requiring client code to explicitly try to read either error
or tuple queues).
--
Thomas Munro
http://www.enterprisedb.com
