[winGRASS] Re: generic Windows GRASS driver

[Mike Thomas]

Hi all.

Debugging the libW11 version of the XDriver - the exposition of my logic may
be a little laborious, but I am coming to grips with the differences between
X11 and Windows from behind the pole position.

OK - further to the report below, it seems that the libW11 display window
closes down as soon as the parent XDRIVER exits - that is, when the message:

    Graphics driver [x0] started - exiting

appears.

My interpretation of this is that the new window is not running as a
separate process and therefore is doomed to die with the process that
launches it (ie the parent XDriver).

I assume that this is not the case with X11 - that is, that the window is
under the control of the XServer rather than the XDriver and is therefore
preserved.

On this basis I used the __W98__ define to stop the parent from exiting.
This buys a display which waits for a response (looping on do_work(0)).

Calling d.erase causes the display to die.  Unfortunately the debugging
output messages keep on coming, without any visible parent process!!!

I'll worry about that tomorrow.

Cheers

Mike Thomas.



----- Original Message -----
From: Mike Thomas <miketh at brisbane.paradigmgeo.com>
To: Glynn Clements <glynn.clements at virgin.net>; Markus Neteler
<neteler at itc.it>
Cc: Roberto Flor <flor at itc.it>
Sent: Thursday, September 20, 2001 5:23 PM
Subject: Re: generic Windows GRASS driver


> Hi there.
>
> > > So, the idea to test is to change the ConnectionNumber(dpy)
> > > to XConnectionNumber(dpy) in Xdriver/Serve_Xevent.c.
> > >
>
> Unfortunately it didn't work - but thanks for the input.
>
> I think I'm going to have to delve further into the meaning of those
> messages in the debug printout returned by get_command eg:
>
> DRIVER main: before get_command
> DRIVER main: before process_command c = K
> DRIVER main: before Do_work(1)
>
> I really want to use gdb to find out exactly when the display disappears,
> but although it attaches to an already running XServer it insists on
> starting a new process.  I end up with two XDrivers and the one being
traced
> by the debugger dies when it tries to get a connection.  Then the debugger
> and the terminal sessions bind up and refuse to shutdown.  Very
frustrating.
>
> I might try inserting a buch of sleep()s at strategic points to slow
> execution down and to catch the window closure point.
>
> Cheers
>
> Mike Thomas.
>
>
>
>
>
>