Race condition seems to be fixed

[John W. Eaton]

On 21-May-2012, Jacob Dawid wrote:

| Hello maintainers,
| 
| I probably fixed the race condition a few minutes ago. What I did was to
| separate the workspace model from the view as a prerequisite in the GUI, then 
I
| added an octave_loop callback into octave's main_loop(), in the same way the
| octave_exit callback was added. Usually, this callback is null, so it won't be
| called when there hasn't been set a callback. I did a hg diff (I hade to 
modify
| toplev.h and toplev.cc) attached to this mail and kindly ask for confirmation
| that I can push this on the GUI branch, see the very bottom of this file.

Please propose the change to the default branch as a patch separate
from any changes on gui branch.

  diff -r 664f54233c98 src/toplev.cc
  --- a/src/toplev.cc   Sun May 20 22:05:49 2012 +0200
  +++ b/src/toplev.cc   Mon May 21 01:20:34 2012 +0200
  @@ -77,6 +77,7 @@
   #include "variables.h"
   #include "version.h"

  +void (*octave_loop) () = 0;
   void (*octave_exit) (int) = ::exit;
 
I think we need better names for these function pointers.

   // TRUE means the quit() call is allowed.
  @@ -560,6 +561,9 @@
       {
         try
           {
  +       if (octave_loop)
  +         (*octave_loop) ();
  +
             unwind_protect frame;

             reset_error_handler ();

I'm not sure this is the best place for the callback.  Should it also
be called when Octave is waiting for input?  What about when it is
evaluating a statement passed to the eval function?  Or when Octave is
doing debugging and evaluating expressions at the debug> prompt?

jwe