On Mon, 1 Jul 2024 17:43:53 +0900 Takashi Yano wrote: > On Sun, 30 Jun 2024 22:55:22 +0900 > Takashi Yano wrote: > > On Sun, 30 Jun 2024 20:33:19 +0900 > > jojelino wrote: > > > 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 > > > > I cannot reproduce the issue. > > > > 1) Which cygwin version do you use? > > 2) Is this really the same problem with the problem original post reported? > > (i.e. reproducible with 3.6.0-0.139 and not reproduced with 3.5.3) > > I could reproduce this (the problem reported by jojelino) by: > mintty -e timeout 1 dash -c 'yes aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | cat' > > This also occurs with cygwin 3.5.3, so it's another problem than Brian > reported. > > This does not occur by: > mintty -e timeout 1 dash -c 'yes aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa' > mintty -e timeout 1 tcsh -c 'yes aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | cat' > script /dev/null -c timeout 1 dash -c 'yes aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa | > cat' > > I looked into this probelm and found the cause. > > When the child process (timeout) is terminated, mintty seems to stop reading > pty master even if yes or cat still alive. (Is this right? >> Thomas) > (This behaviour seems to be a side efect of patch_319(?) in mintty.) > > If the the pipe used to transfer output from pty slave to pty master is full > due to lack of master reader, WriteFile() to the pipe is blocked. WriteFile() > cannot be canceled by cygwin signal, therefore, pty slave hangs. > > I'll submit and push a patch to fix this. > > Thanks for finding this issue. >> jojelino
Please test cygwin-3.6.0-0.145.gc4fb5da27876 Cygwin 3.5.4 will come with this fix. -- Takashi Yano <takashi.y...@nifty.ne.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
