Greg Stark <gsstark(at)mit(dot)edu> writes:
> If you're going to have a special flag indicating this couldn't you just have
> a special flag indicating that the offset isn't ready yet? Loop until that
> flag is cleared instead of looking for offset != 0 at all.
Well, the whole idea didn't work anyway :-(. But I think your proposal
is equivalent to holding the lock throughout CreateMultiXactId, which is
exactly what we're trying to avoid doing ...
regards, tom lane