Emacs-25: stop-process has no effect on linux

Emacs-25: stop-process has no effect on linux

[raman]

This is Emacs 25 built from Git @head.

delete-process and interrupt-process work as expected, but
stop-process appears to be a no up -- tested with both
process-connection-type let-bound to nil and t.


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Re: Emacs-25: stop-process has no effect on linux

[Eli Zaretskii]

> From: raman@google.com
> Date: Mon, 21 Dec 2015 08:29:37 -0800
> 
> 
> This is Emacs 25 built from Git @head.
> 
> delete-process and interrupt-process work as expected, but
> stop-process appears to be a no up -- tested with both
> process-connection-type let-bound to nil and t.

Can you show what did you try, exactly, and with what program as the
sub-process?

Thanks.

Re: Emacs-25: stop-process has no effect on linux

[T.V Raman]

Here is a simple test:

(setq proc 
      (let ((process-connection-type nil)); also tried with t 
(start-process "play" "Play" "play" ; play is from sox 
<myfile.mp3>)))
(process-status proc) -- run if it worked 
(stop-process proc) -- no-op
(delete-process proc) ; kills it

The same happens if you substitute play with mplayer.
Eli Zaretskii writes:
 > > From: raman@google.com
 > > Date: Mon, 21 Dec 2015 08:29:37 -0800
 > > 
 > > 
 > > This is Emacs 25 built from Git @head.
 > > 
 > > delete-process and interrupt-process work as expected, but
 > > stop-process appears to be a no up -- tested with both
 > > process-connection-type let-bound to nil and t.
 > 
 > Can you show what did you try, exactly, and with what program as the
 > sub-process?
 > 
 > Thanks.

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Re: Emacs-25: stop-process has no effect on linux

[Eli Zaretskii]

> From: raman@google.com (T.V Raman)
> Date: Mon, 21 Dec 2015 09:15:07 -0800
> Cc: raman@google.com,
>     emacs-devel@gnu.org
> 
> Here is a simple test:
> 
> (setq proc 
>       (let ((process-connection-type nil)); also tried with t 
> (start-process "play" "Play" "play" ; play is from sox 
> <myfile.mp3>)))
> (process-status proc) -- run if it worked 
> (stop-process proc) -- no-op
> (delete-process proc) ; kills it
> 
> The same happens if you substitute play with mplayer.

Could it be that these two programs catch and ignore SIGTSTP?  That's
the signal sent by stop-process.  Can you stop them with "kill -TSTP"
from the shell prompt?

Re: Emacs-25: stop-process has no effect on linux

[T.V Raman]

Yes, I verified that before reporting the issue -- C-c C-z in a shell
running either play or mplayer works, they also respond correctly to
being resumed at the shell by typing "fg" or "bg"

Eli Zaretskii writes:
 > > From: raman@google.com (T.V Raman)
 > > Date: Mon, 21 Dec 2015 09:15:07 -0800
 > > Cc: raman@google.com,
 > >     emacs-devel@gnu.org
 > > 
 > > Here is a simple test:
 > > 
 > > (setq proc 
 > >       (let ((process-connection-type nil)); also tried with t 
 > > (start-process "play" "Play" "play" ; play is from sox 
 > > <myfile.mp3>)))
 > > (process-status proc) -- run if it worked 
 > > (stop-process proc) -- no-op
 > > (delete-process proc) ; kills it
 > > 
 > > The same happens if you substitute play with mplayer.
 > 
 > Could it be that these two programs catch and ignore SIGTSTP?  That's
 > the signal sent by stop-process.  Can you stop them with "kill -TSTP"
 > from the shell prompt?

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Re: Emacs-25: stop-process has no effect on linux

[John Wiegley]

>>>>> T V Raman <raman@google.com> writes:

> Yes, I verified that before reporting the issue -- C-c C-z in a shell
> running either play or mplayer works, they also respond correctly to being
> resumed at the shell by typing "fg" or "bg"

Can you please log a bug on this, and copy the relevant details from this
discussion into that bug. I feel much more comfortable about discussing issues
under a ticket number, than possibly losing track of them here on emacs-devel.

Thanks,
-- 
John Wiegley                  GPG fingerprint = 4710 CF98 AF9B 327B B80F
http://newartisans.com                          60E1 46C4 BD1A 7AC1 4BA2