[V3dot10] Fwd: Some Delay tweaks

[Damien Cassou]

---------- Forwarded message ----------
From: Andreas Raab <andreas.raab at gmx.de>
Date: 31 août 2007 05:52
Subject: Some Delay tweaks
To: The general-purpose Squeak developers list
<squeak-dev at lists.squeakfoundation.org>


Hi -

Just FYI, I've updated http://bugs.squeak.org/view.php?id=6576 with
another change set containing a few relevant tweaks to Delay. The most
important one is probably the one which ensures that Delays get
unscheduled if the process they wait for is terminated. The problem is
that delays which are scheduled are kept in the SuspendedDelays even
after "their" process terminates. So that, for example a "(Delay
forSeconds: 9999999) wait" (with an Alt-Period following it) would leave
that delay being scheduled for expiry 100 days from now although its
process is long gone.

The tweaks also ensure that delays which actually expire in
Semaphore>>waitTimeoutMSecs: don't get unscheduled twice (since
unscheduling is a linear search over all scheduled delays it should be
avoided).

Lastly, there is a bit of bullet-proofing to Delay>>handleTimerEvent
since each poll of the msecs clock has the potential to overflow and
needs to be guarded explicitly. The tweaks make sure there is only one
such poll and consequently only one place to check. Except from another
obscure situation which the change set addresses as well.

In any case, it's a nice roundup for the Delay changes. If you're using
the first one, you should probably use this one as well.

Cheers,
   - Andreas



-- 
Damien Cassou