Re: Gtkmm and fork()

[Chris Vine <chris cvine freeserve co uk>]

On Sun, 11 Apr 2010 08:23:56 -0700 (PDT)
"Adam Chyla [PL]" <adam chyla gmail com> wrote:
> I have been trying MKs code, but it isn't working.
> 
> #include <gtkmm.h>
> #include <iostream>
> 
> using namespace std;
> 
> vector<pid_t> Pids;
> 
> void buttonpress() {
>        static int i = 0;
>        i++;
>        pid_t pid = fork();
>        cerr << i<< ": " << pid <<endl;
>        if (!pid) {
>                Gtk::Main::quit();
> int i = 6;
>                while (i) {
>                        sleep(1);
>                        cerr << i << " hello world" << endl; i--;
>                }
>        } else Pids.push_back(pid);
> }
> 
> int main(int argc, char *argv[]) {
>        Gtk::Main kit(argc, argv);
>        Gtk::Window win;
>        Gtk::VBox box;
>        Gtk::Button but("click me");
> 
>        win.set_title("gtkmm test");
>        win.set_size_request(400,200);
>        win.add(box);
> 
>        box.pack_start(but);
>        but.signal_clicked().connect(
>                sigc::ptr_fun(buttonpress),false);
> 
>        win.show_all();
>        kit.run(win);
> 
>        vector<pid_t>::iterator it = Pids.begin(),
>                end =  Pids.end();
>        while(it != end) kill(*(it++),9);
> 
>        return 0;
> }
> 
> 
> Output:
> adam Adam:~/Pulpit$ ./a.out 
> 1: 5874
> 1: 0
> 6 hello world
> 5 hello world
> 4 hello world
> 3 hello world
> 2 hello world
> 1 hello world
> a.out: Fatal IO error 11 (Resource temporarily unavailable) on X
> server :0.0.
> a.out: ../../src/xcb_io.c:249: process_responses: Assertion `(((long)
> (dpy->last_request_read) - (long) (dpy->request)) <= 0)' failed.
> Aborted (core dumped)

You should call _exit() (and incidentally NOT exit()) at the end of the
child process.  (That is at the end of the if block representing the
child process.)

Chris