Re: src/backend/storage/lmgr/lock.c ----> LockAcquire()

"S -" <nat_lazy(at)hotmail(dot)com> writes:
> -- Within a SINGLE call of LockAcquire, is it possible for GrantLock() to be
> called multiple times?

Hmm. In the normal course of events, a LockAcquire would only try to
grant the target lock to itself; it couldn't grant anything to anyone
else as a byproduct. But I think there might be corner cases involving
deadlock detection. Once a deadlock is detected, the resulting
transaction abort leads to lock releases which lead to lock grants
occurring --- so how narrowly are you defining "a single call of
LockAcquire"?

In any case a single call of LockRelease can certainly result in
multiple GrantLocks, so I'm not sure what sort of optimization you might
have in mind that would be feasible.

regards, tom lane