Re: [PATCHES] Win32 CHECK_FOR_INTERRUPTS() performance

[Qingqing Zhou <zhouqq(at)cs(dot)toronto(dot)edu>]

On Sun, 23 Oct 2005, Magnus Hagander wrote:

>
> But. in theory, we can get a false positive from
> UNBLOCKED_SIGNAL_QUEUE(), right? Since we do it unlocked between two
> threads. If we do that, we'll "recover" in dispatch_signals, because
> we'l lcheck again locked and not dispatch any signals. *but*. If this
> happens, we will return EINTR even when there is no signal. That doesn't
> seem correct to me. It's a very small window, but it should be possible,
> no?
>
> We probably need an actual check, so for example have
> dispatch_queued_signals return a value indicating if any signals were
> actually dispatched, and use that to control EINTR?
>
> Comments? Or am I completely off being too tired right now? ;-)
>

You are not. Basically that's what I just sent an email about :-) Since
signals are not quite often happened, so I am thinking just adding a
UNBLOCKED_SIGNAL_QUEUE() is more safe maybe for now.

Regards,
Qingqing