DKIM-Filter:	OpenDKIM Filter v2.11.0 delorie.com 45UBYZl0363754
Authentication-Results:	delorie.com;
	dkim=pass (1024-bit key, unprotected) header.d=cygwin.com header.i=@cygwin.com header.a=rsa-sha256 header.s=default header.b=v4PkOpaa
X-Recipient:	archive-cygwin AT delorie DOT com
DKIM-Filter:	OpenDKIM Filter v2.11.0 sourceware.org 0194C38323FE
DKIM-Signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1719747274;
	bh=V22It8DiqGz5Lexk64zolYM6ShEIf6ZCThsx3y7PMnw=;
	h=To:Subject:Date:References:In-Reply-To:List-Id:List-Unsubscribe:
	List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:
	From;
	b=v4PkOpaaJ9P/8MkoqAV9R8HvPXvTJYTugHmUEe3ErIBQWei6tttMhkI2r75Hh3REe
	leV5XYeZhODSfbtv80f8BOTk80osrprDybMXNL9AqA6sHse4K6EwBKjcq0WHtTRfB6
	Xe7LErXn4wi1JWUnO2PoVuaHGX2Lmf35xbkAdi2w=
X-Original-To:	cygwin AT cygwin DOT com
Delivered-To:	cygwin AT cygwin DOT com
DMARC-Filter:	OpenDMARC Filter v1.4.2 sourceware.org A1130386547E
ARC-Filter:	OpenARC Filter v1.0.0 sourceware.org A1130386547E
ARC-Seal:	i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1719747219; cv=none;
	b=iRaGaH7fpgVap9kNJ4478YqC0FpPw/sRbV4ojbj6yBH/JanhEm8TPFSa2fRKKgGzb6/blXchFvGpVhxb4S+4GFk73AEXO48O6AmflYwPJ8ixe9DelvX6SXkh2T0pd3+ogklaRDIecQh9kxf31UCBz2X10qy32KV7Vh2m9GlfqYo=
ARC-Message-Signature:	i=1; a=rsa-sha256; d=sourceware.org; s=key;
	t=1719747219; c=relaxed/simple;
	bh=jGLxCXmx3NtZHstvR5aYjg1NOszNYTSmovMp0g62JH0=;
	h=To:From:Subject:Date:Message-ID:Mime-Version;
	b=GtaaoBhYYWfhY9a5yzQXhl7jfsnfvDcWSG2fD7qwqwBpjPwQ+RYhiEsnCCuuGnJYgEBTL6ho2H3Xg4vO0KwMx4dpfkYkyG6DM0Pl1ZXcJU3JHk4fDwWmhAUpdQSed4K4/n2GRsVDmSUg84/CSu4jfKanQtTKOyCG7Kd1MVQA49s=
ARC-Authentication-Results:	i=1; server2.sourceware.org
X-Injected-Via-Gmane:	http://gmane.org/
To:	cygwin AT cygwin DOT com
Subject:	Re: ssh-add -l hangs under cygwin test 3.6.0-0.139.g...
Date:	Sun, 30 Jun 2024 20:33:19 +0900
Message-ID:	<19c300bb-97ff-4dee-be8c-2215b38f0a1c@gmail.com>
References:	<bd97f4a1-0298-4422-8594-40f0989d13ce AT SystematicSW DOT ab DOT ca>
Mime-Version:	1.0
User-Agent:	Thunderbird Daily
In-Reply-To:	<bd97f4a1-0298-4422-8594-40f0989d13ce@SystematicSW.ab.ca>
X-Spam-Status:	No, score=-0.6 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,
	FORGED_GMAIL_RCVD, FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,
	HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, NML_ADSP_CUSTOM_MED,
	SPF_HELO_NONE, SPF_PASS, TXREP,
	WEIRD_PORT autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version:	SpamAssassin 3.4.6 (2021-04-09) on
	server2.sourceware.org
X-BeenThere:	cygwin AT cygwin DOT com
X-Mailman-Version:	2.1.30
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:	jojelino via Cygwin <cygwin AT cygwin DOT com>
Reply-To:	jojelino <jojelino AT gmail DOT com>
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 6/29/2024 2:39 PM, Brian Inglis via Cygwin wrote:
> Reran cygport --debug upload and command hanging was ssh-add -l!
> 
   296   72109 [main] ssh-add 63275 win32env_to_cygenv: 0xA000232E0: 
TERM_PROGRAM=mintty
   189   72298 [main] ssh-add 63275 win32env_to_cygenv: 0xA00023300: 
TERM_PROGRAM_VERSION=3.7.1

I was able to reproduce this problem by entering below command with 
ffmpeg from https://www.gyan.dev/ffmpeg/builds/ , this ffmpeg build 
spams putc. So, without piping its output to `tee', It would not 
possible track down any cause among lengthy trace output.

strace mintty -e /bin/timeout 10 sh -c './ffmpeg -h full|& tee'

In summary, When `timeout' expires, `timeout' signals SIGHUP to pgrp of 
itself, btw some member of the pgrp may have acquired any of 
synchronization object of some part of cygwin internal when a member 
process of the pgrp did encounter the signal interrupt from `timeout'. 
In my case it was output_mutex of pty.

  1565 10693297 [main] timeout 745 kill_pgrp: pid 0, signal 15
  2701 15224348 [main] mintty 744 
fhandler_pty_master::process_slave_output: bytes read 256
  1736 9525442 [sig] sh 746 proc_subproc: args: 4, 1
  3137 6700294 [main] tee 748 fhandler_pty_slave::write: pty5, 
write(0x7FFFFC780, 1024)
  1347 9526789 [sig] sh 746 proc_subproc: clear waiting threads
  2084 15226432 [main] mintty 744 
fhandler_pty_master::process_slave_output: returning 256
  1110 6701404 [main] tee 748 fhandler_pty_slave::write: (1267): pty 
output_mutex (0x4C0): waiti
-1 ms
   732 9527521 [sig] sh 746 checkstate: child_procs count 2
  3648 10696945 [main] timeout 745 open_shared: name cygpid.724, shared 
0x1A0050000 (wanted 0x1A
0000), h 0x16C, m 6, created 0
  1055 6702459 [main] tee 748 fhandler_pty_slave::write: (1267): pty 
output_mutex: acquired

  2092 15753306 [main] mintty 744 fhandler_pty_master::close: (2095): 
pty output_mutex (0x4AC):
ting -1 ms

And below is a location where `tee' did hang.

#3  0x00007ffd0e408fdf in fhandler_pty_slave::write (this=0x800009a10,
     ptr=0x7ffffc780, len=<optimized out>)
     at ../../.././winsup/cygwin/fhandler/pty.cc:1268
1268      if (!process_opost_output (get_output_handle (), ptr, towrite, 
false,
(gdb)  li
1263      termios_printf ("pty%d, write(%p, %lu)", get_minor (), ptr, len);
1264
1265      push_process_state process_state (PID_TTYOU);
1266
1267      acquire_output_mutex (mutex_timeout);
1268      if (!process_opost_output (get_output_handle (), ptr, towrite, 
false,
1269                                 get_ttyp (), is_nonblocking ()))


I ended up prepending two CancelIo call just above of 
acquire_output_mutex located in fhandler_pty_master::close of pty.cc.

 >	  CancelIo(get_ttyp()->to_master());
 >	  CancelIo(get_ttyp()->to_master_nat());
	  acquire_output_mutex (mutex_timeout);

Hope it helps


-- 
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 -