On 24.05.2012 16:04, Sandro Santilli wrote:
On Wed, May 16, 2012 at 07:30:03PM +0300, Heikki Linnakangas wrote:
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.
No place is safe if CHECK_FOR_INTERRUPTS doesn't return.
How could caller code cleanup on interruption ?
It would only be safe to call it in places where no cleanup is
necessary. I don't know if there are any such places in the geos library.
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
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