From: Erik Faye-Lund <kusmabite@gmail.com>
Date: Fri, 01 Apr 2011 20:13:23 GMT
Subject: Re: [PATCH 5/4] run-command: implement abort_async for pthreads
Message-ID: <AANLkTi=ro88pwpA+Gfu5p2dB3ntn8PUcwvjHRh3iRy_H@mail.gmail.com>
In-Reply-To: <20110401200537.GA15778@sigill.intra.peff.net>

On Fri, Apr 1, 2011 at 10:05 PM, Jeff King <peff@peff.net> wrote:
> On Fri, Apr 01, 2011 at 09:57:14PM +0200, Erik Faye-Lund wrote:
>
>> > But this does not help the case at hand in any way. How would you interrupt a
>> > thread that is blocked in ReadFile()? The point of pthread_cancel() is that
>> > it interrupts blocked system calls
>>
>> There is no mention of such a guarantee in POSIX (section 2.9.5 Thread
>> Cancellation), so relying on that is undefined behavior.
>
> Eh? My pthreads(7) says that read() is required to be a cancellation
> point acrroding to POSIX. I didn't dig up the actual reference in the
> standard, though.

I don't understand where the implementor would get that from after
reading through it, but if there's something I've missed we can fix it
by replacing my pthread_cancel with this, no?

static inline int pthread_cancel(pthread_t thread)
{
	SetEvent(thread.cancel_event);
	CancelSynchronousIo(thread.handle);
}