Re: -persist and the wxWidgets terminal, continued

[Daniel J S. <dan...@ie...>]

Timoth=C3=A9e Lecomte wrote:
> Hi,
>=20
> I just tried the wxWidgets terminal with octave (2.1.73, not the last=20
> development version though).
>=20
> Bad news : it uses "persist" too.

Are you sure?  I've never seen plots stay alive after Octave is closed.  =
I've gone to the Octave source directory and grepped for "persist".  I do=
n't see it anywhere used as an option to gnuplot, and the line of code I =
see uses "gnuplot" as the default launch command.

Please use 2.9.x series as reference.  There are major changes in store f=
or Octave.  If you must compile, I know, it takes a while.

>=20
> octave uses a pipe to talk with gnuplot, and keeps it open through the=20
> whole octave session. The "persist" behaviour appears when you close=20
> octave (by issuing "quit" at octave prompt). I guess the process goes=20
> the following way : octave closes the pipe, gnuplot engages its exit=20
> process, the wxWidgets says "hold on !" until all the windows are=20
> closed, and ... octave waits for gnuplot to terminate, so you end up=20
> with what looks like a frozen prompt until you realize that you have to=
=20
> close the wxt window (you can also hit ctrl-c twice to force octave to=20
> close).
>=20
> Like maxima, octave relies on the X11 "persist" behaviour.

I don't think so.

>=20
> Ethan suggested two alternatives :
> - sending a fake signal SIGCHLD to octave, meaning "child process=20
> terminated". I tried, and it does not work. octave does not wait for SI=
GCHLD
> - mimic a 'bg' to gnuplot. Well, I don't know how to do that from=20
> gnuplot, and I doubt it will actually work : since gnuplot's process is=
=20
> still running, octave still waits for it.
>=20
> Do any of you have a miraculous idea, or should I report that to the=20
> octave developers as I did for maxima ?

Talk directly with John Eaton.  He's the only one who will know.  But I'd=
 say it would be best to compile the latest version and come up with a pa=
tch that works with what you are trying to accomplish.  (The file __gnupl=
ot_raw__.cc contains what you are looking for.)

Dan