Re: pgsql: Move btbulkdelete's vacuum_delay_point()

Simon Riggs <simon(at)2ndquadrant(dot)com> writes:
> if (LWLockNumHeldByMe() == 0)
> pg_usleep(msec * 1000L);
> else
> elog(WARNING, "losing sleep because internal locks are held");

I did some testing yesterday with an Assert added to vacuum_delay_point:
Assert(InterruptHoldoffCount == 0 && CritSectionCount == 0);
which is basically asserting that ProcessInterrupts is allowed to
execute an interrupt. I desisted from committing this test, though,
because it's not clear that callers should not be allowed to call
vacuum_delay_point in such cases --- for the current callers it proved
fairly easy to locate the calls at places where this is certain to be OK,
but I don't want to wire in a requirement of it.

In any case, such tests don't help for the question of whether we've
missed any major loops that ought to contain vacuum_delay_point calls.
(If we were to add a worst-case-interval measurement, it might be
reasonable to not count calls that don't meet the ProcessInterrupts
condition.)

regards, tom lane