X-Recipient:	archive-cygwin AT delorie DOT com
DKIM-Filter:	OpenDKIM Filter v2.11.0 sourceware.org 1CC67385840B
DKIM-Signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1636501797;
	bh=oBA2O0FdJKd+uN47Ih5+B7s17IDqt4tu3lR0jCP9VyI=;
	h=Date:To:Subject:In-Reply-To:References:List-Id:List-Unsubscribe:
	List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:
	From;
	b=hNtsumU+uhKvVMxO7U90MUiY4U2OIGIEH1M1uEh59nkGKmzpBH4P9kx03NLFrk4WN
	PlSH3eIkNdmXeBU9GcIspoOZEuiGpSOZJKjkyNn5rOPH+5kdAGohjvwcg2IIUWMcQH
	ynS+lB0MXhLgLDzcPs96HX0oc34D/qm8XsF4z5ZY=
X-Original-To:	cygwin AT cygwin DOT com
Delivered-To:	cygwin AT cygwin DOT com
DMARC-Filter:	OpenDMARC Filter v1.4.1 sourceware.org 41FD53858405
DKIM-Filter:	OpenDKIM Filter v2.10.3 conssluserg-04.nifty.com 1A9NmF1q010262
X-Nifty-SrcIP:	[110.4.221.123]
Date:	Wed, 10 Nov 2021 08:48:22 +0900
To:	cygwin AT cygwin DOT com
Subject:	Re: Another pipe-related problem?
Message-Id:	<20211110084822.fa32acb567bd26ab43c393bd@nifty.ne.jp>
In-Reply-To:	<20211110082932.3e33bae9364db0dda0c57d16@nifty.ne.jp>
References:	<f5br1bqaj11 DOT fsf AT ecclerig DOT inf DOT ed DOT ac DOT uk>
	<05c4180e-396b-4af3-ac0c-2ab8125df17e AT cornell DOT edu>
	<f5bk0hh8uox DOT fsf AT ecclerig DOT inf DOT ed DOT ac DOT uk>
	<eb8d7d4f-d1ed-6f30-2ac3-1b24166243d9 AT cornell DOT edu>
	<20211110082245 DOT 2943cf3c2519bff24a6843b2 AT nifty DOT ne DOT jp>
	<20211110082932 DOT 3e33bae9364db0dda0c57d16 AT nifty DOT ne DOT jp>
X-Mailer:	Sylpheed 3.7.0 (GTK+ 2.24.30; i686-pc-mingw32)
Mime-Version:	1.0
X-Spam-Status:	No, score=-5.9 required=5.0 tests=BAYES_00, DKIM_SIGNED,
	DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, NICE_REPLY_A, RCVD_IN_DNSWL_NONE,
	SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4
X-Spam-Checker-Version:	SpamAssassin 3.4.4 (2020-01-24) on
	server2.sourceware.org
X-BeenThere:	cygwin AT cygwin DOT com
X-Mailman-Version:	2.1.29
List-Id:	General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe:	<https://cygwin.com/mailman/options/cygwin>,
	<mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive:	<https://cygwin.com/pipermail/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe:	<https://cygwin.com/mailman/listinfo/cygwin>,
	<mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From:	Takashi Yano via Cygwin <cygwin AT cygwin DOT com>
Reply-To:	Takashi Yano <takashi DOT yano AT nifty DOT ne DOT jp>
Errors-To:	cygwin-bounces+archive-cygwin=delorie DOT com AT cygwin DOT com
Sender:	"Cygwin" <cygwin-bounces+archive-cygwin=delorie DOT com AT cygwin DOT com>

On Wed, 10 Nov 2021 08:29:32 +0900
Takashi Yano wrote:
> On Wed, 10 Nov 2021 08:22:45 +0900
> Takashi Yano wrote:
> > On Tue, 9 Nov 2021 09:11:28 -0500
> > Ken Brown wrote:
> > > I'll have to reproduce the hang myself in order to test this (or maybe you could 
> > > test it), but I now have a new guess: If the read call above keeps failing with 
> > > EINTR, then we're in an infinite loop.  This could happen because of the 
> > > following code in fhandler_pipe::raw_read:
> > > 
> > >    DWORD waitret = cygwait (read_mtx, timeout);
> > >    switch (waitret)
> > >      {
> > >      case WAIT_OBJECT_0:
> > >        break;
> > >      case WAIT_TIMEOUT:
> > >        set_errno (EAGAIN);
> > >        len = (size_t) -1;
> > >        return;
> > >      default:
> > >        set_errno (EINTR);
> > >        len = (size_t) -1;
> > >        return;
> > >      }
> > > 
> > > Takashi, is EINTR really the appropriate errno in the default case?  Isn't 
> > > cygwait supposed to handle signals?
> > 
> > I assume cygwait() returns WAIT_SIGNALED when signalled
> > by SIGINT, SIGTERM, SIGTSTP, etc...  In this case, EINTR
> > should return I think.
> > 
> > Is it wrong?
> 
> Ah, if SA_RESTART is set, we should continue to read even
> if signalled...

So, should this be like following?

 restart_wait_read_mtx:
   DWORD waitret = cygwait (read_mtx, timeout, cw_sig_eintr);
   switch (waitret)
     {
     case WAIT_OBJECT_0:
       break;
     case WAIT_TIMEOUT:
       set_errno (EAGAIN);
       len = (size_t) -1;
       return;
     case WAIT_SIGNALED:
       if (_my_tls.call_signal_handler ())
         goto restart_wait_read_mtx;
       set_errno (EINTR);
       len = (size_t) -1;
       return;
     default:
       /* Should not reach here. */
       __seterrno ();
       len = (size_t) -1;
       return;
     }

-- 
Takashi Yano <takashi DOT yano AT nifty DOT ne DOT jp>

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple

- Raw text -