Re: fork() and main_quit()

["Mike Schilli" <b2b perlmeister com>]

Daniel Flemming wrote on 9/11/2004, 12:04 PM:

> If you're communicating via pipes anyway, can't you send a command
> over the pipe
> from the parent process to cause the child to exit? Surely that'd be
> easier than
> setting up signal handlers in the child.

That would certainly be an option, but I just wanted something simple.

I've played with different approaches since the original post and it 
looks like calling init() *after* the fork in the parent *only* is 
indeed the solution to the problem.

If you don't do that, like in

     use Gtk2 -init;

     my $pid = fork();

     die "Fork failed" unless defined $pid;

     if($pid) {
         print "Parent: Child pid is $pid\n";
     } else {
         # Child
         print "Child: My pid is $$\n";
         sleep(120);
         exit 0;
     }

         # Parent
     my $window = Gtk2::Window->new ('toplevel');
     my $button = Gtk2::Button->new ('Quit');
     $button->signal_connect (clicked => sub {
         kill $pid;
         Gtk2->main_quit });
     $window->add ($button);
     $window->show_all;
     Gtk2->main;

you get the described mess. If, however, you call init() manually 
*after* the fork and only in the parent, it works fine:

     use Gtk2;

     my $pid = fork();

     die "Fork failed" unless defined $pid;

     if($pid) {
         Gtk2->init();
         print "Parent: Child pid is $pid\n";
     } else {
         # Child
         print "Child: My pid is $$\n";
         sleep(120);
         exit 0;
     }

         # Parent
     my $window = Gtk2::Window->new ('toplevel');
     my $button = Gtk2::Button->new ('Quit');
     $button->signal_connect (clicked => sub {
         kill $pid;
         Gtk2->main_quit });
     $window->add ($button);
     $window->show_all;
     Gtk2->main;

Thanks for your help on this, guys!

--
-- Mike
Mike Schilli
m perlmeister com