Re: Interrupting long external library calls

On 16.05.2012 15:42, Sandro Santilli wrote:
> But CHECK_FOR_INTERRUPTS doesn't return, right ?
> Is there another macro for just checking w/out yet acting upon it ?

Hmm, no. CHECK_FOR_INTERRUPTS() checks the InterruptPending variable,
but on Windows it also checks for UNBLOCKED_SIGNAL_QUEUE(). And even if
InterruptPending is set, it's not totally certain that
CHECK_FOR_INTERRUPTS() won't return. I think InterruptPending can be set
spuriously (even if that's not possible today, I wouldn't rely on it),
and if you're in a HOLD/RESUME_INTERRUPTS block, CHECK_FOR_INTERRUPTS()
will do nothing even if InterruptPending is true.

The only sane way to make 3rd party code interruptible is to add
CHECK_FOR_INTERRUPTS() to it, in safe places.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com