Re: [PATCH 5/4] run-command: implement abort_async for pthreads

From: Erik Faye-Lund <kusmabite@gmail.com>
Date: Apr 1, 2011, 20:34 UTC
Message-ID: <AANLkTinr+_9tHj8neHOxZMtKRMQ3LSVzqCPpjFup2hy=@mail.gmail.com>
In-Reply-To: <20110401201714.GA16501@sigill.intra.peff.net>

On Fri, Apr 1, 2011 at 10:17 PM, Jeff King <peff@peff.net> wrote:

Show 24 quoted lines

> On Fri, Apr 01, 2011 at 10:13:23PM +0200, Erik Faye-Lund wrote:
>
>> 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?
>
> Out of curiosity, which POSIX are you reading? My page references
> POSIX.1-2001, but technically pthreads were originally defined in
> POSIX.1c-1995.
>

Sorry that I wasn't more clear about this:

"The Open Group Base Specifications Issue 6" "IEEE Std 1003.1, 2004 Edition"

Available here: http://pubs.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_09.html