From: Takashi Yano <takashi.yano@nifty.ne.jp>
To: cygwin@cygwin.com
Subject: Re: Another pipe-related problem?
Date: Wed, 10 Nov 2021 09:37:41 +0900 [thread overview]
Message-ID: <20211110093741.d15b99a1361e680f87b61fd8@nifty.ne.jp> (raw)
In-Reply-To: <20211110091613.26a636e789fe36a098412f1b@nifty.ne.jp>
On Wed, 10 Nov 2021 09:16:13 +0900
Takashi Yano wrote:
> On Wed, 10 Nov 2021 08:48:22 +0900
> Takashi Yano wrote:
> > 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...
[...]
> No, we don't have to do that because cygwait() do the same
> internally. cygwain() returns WAIT_SIGNALED when signalled
> only if SA_RESTART is not set. So, the current code LGTM.
Ah, however, should we handle WAIT_CANCELED here and call
pthread::static_cancel_self() as following?
DWORD waitret = cygwait (read_mtx, timeout);
switch (waitret)
{
case WAIT_OBJECT_0:
break;
case WAIT_TIMEOUT:
set_errno (EAGAIN);
len = (size_t) -1;
return;
WAIT_SIGNALED:
set_errno (EINTR);
len = (size_t) -1;
return;
WAIT_CANCELED:
pthread::static_cancel_self ();
/* NOTREACHED */
default:
/* Should not reach here. */
__seterrno ();
len = (slze_t) -1;
return;
}
--
Takashi Yano <takashi.yano@nifty.ne.jp>
next prev parent reply other threads:[~2021-11-10 0:37 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-08 13:12 Henry S. Thompson
2021-11-08 14:35 ` Ken Brown
2021-11-08 18:52 ` Ken Brown
2021-11-09 10:55 ` Henry S. Thompson
2021-11-09 14:11 ` Ken Brown
2021-11-09 14:47 ` Henry S. Thompson
2021-11-09 22:16 ` Ken Brown
2021-11-09 22:20 ` Ken Brown
2021-11-10 2:53 ` Ken Brown
2021-11-10 3:51 ` Backwoods BC
2021-11-10 14:47 ` Ken Brown
2021-11-10 17:23 ` Henry S. Thompson
2021-11-10 18:03 ` Ken Brown
2021-11-10 18:42 ` Henry S. Thompson
2021-11-10 23:07 ` Andrey Repin
2021-11-11 11:06 ` Andrey Repin
2021-11-11 14:16 ` Ken Brown
2021-12-08 21:09 ` XEmacs versus Cygwin 3.3 (was Re: Another pipe-related problem?) Henry S. Thompson
2021-12-09 8:39 ` Aidan Kehoe
2021-11-09 23:22 ` Another pipe-related problem? Takashi Yano
2021-11-09 23:29 ` Takashi Yano
2021-11-09 23:48 ` Takashi Yano
2021-11-10 0:16 ` Takashi Yano
2021-11-10 0:37 ` Takashi Yano [this message]
2021-11-10 2:02 ` Ken Brown
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