G, I've seen most of the other responses, and better understand what you are trying to do. And like others -- fork() is not recommended.
I had similar problem and resolved it in this codeset. http://gfhcm.sourceforge.net -- a monitor for the [EMAIL PROTECTED] project First, like you I needed to start several executables in the background, resolve their identify via pid number, and monitor their cpu utilization and associated artifacts to gage their progress. I approached it two ways: with standalone gfhcm, and then in client/server way using gfhcmc & gfhcmd; gfhcmc is the gtk gui and gfhcmd is a glib helper daemon. For your issue: I suggest g_[a]sync_command_line() as a way to launch a background process from a gtk app. Then using either ipc Queues, pipes, or sockets to connect to process to echange commands and information. Having a formal daemon will help the issue of starting/stopping the background thread. and Finally a dedicated gui that expects to use an IPC to communication with the process. Anyway that you would like to proceed - I think we all can offer solutions. But be clear, I and maybe we think, forking is a bad ideal for GTK program period. My website may have something of interest: http://mysite.verizon.net/skoona/id2.html James, On Tue, 2008-07-08 at 06:51 +0200, G Hasse wrote: > On Mon, Jul 07, 2008 at 10:58:36PM -0400, James Scott Jr wrote: > > G, > > > > The basic design decision to use fork() as a way to do work in the > > background flawed. fork()ing is not practical for gtk program. While > > fork() has been a valid option for many non-gui programs in the absence > > of threads, either g_thread_create() or pthread_create(). Today it is > > not very useful -- as in stop doing it now! > > > > Consider instead using a valid multi-threaded implementation like > > g_threads_xxx() for GTK based programs. Or if full multi-threading is > > not required, look at g_timeout_add() which is a background timer > > routine that can serve as one or more background execution units; neatly > > inside an gtk context. > > This is not a very practical solution if I want to quit the gtk program > and go home... The example I gave was just an example. I want to create > a process that run for a VERY long time. (a week). And to have the GUI > running allong is not a solution. This process don't need to communicate > with the GUI. And if so I can connect to the process with a socket and > ask for services. > > > > > $ devhelp > > $ gtk-demo > > > > The above two program you be pre-installed on your Linux machine: > > devhelp has the gtk and glib api documentation, and gtk-demo shows you > > many of the gtk/glib features in action. > > > > Having said the multi-thread phrase, here is another word of caution. > > In GTK only the main or ONE thread can safely interface with GTK api > > calls that change the display. Using more than one thread to call gtk > > apis at the same time will fail or cause a sigfault. The context of GTK > > being your front-end to X11 is the source of this > > none-thread-safe-caution; it is in how gtk MUST interact with X that > > placing the multi-thread restriction. There are elegant work-arounds > > this issue. > > > > Here is a link to the classic FAQ answer on Multi-threaded GTK programs: > > http://library.gnome.org/devel/gtk-faq/stable/x482.html > > > > Regards, > > James, > > Tanks for your answer but I don't thing threads is the solution in my > case. > > > > > On Mon, 2008-07-07 at 23:03 +0200, G Hasse wrote: > > > Hello, > > > > > > I have a small demo app. This works on FreeBSD but I can't > > > get to work on Linux. I know that in Linux setsid will fail > > > if the child has the same session_id as the parent. So on > > > Linux you must fork twice. But it also seems that the parent > > > must do an exit. And I don't want that. The code is not very > > > long - so I include it here. > > > > > > ---<snipp>--- > > > //---------------------------------------------------------------------- > > > // > > > // $Id: GtkFork.c,v 1.2 2008/07/07 20:29:17 gorhas Exp $ > > > // > > > // Experiment to run a thing in background > > > // This works on FreeBSD but not on Linux... > > > // > > > // Build with > > > // > > > // CFLAGS := `pkg-config glib-2.0 --cflags` `pkg-config gtk+-2.0 > > > --cflags` > > > // LDFLAGS := `pkg-config glib-2.0 --libs` `pkg-config gtk+-2.0 --libs` > > > // > > > // cc $(CFLAGS) -o GtkFork GtkFork.c $(LDFLAGS) > > > // > > > //---------------------------------------------------------------------- > > > > > > #include <gtk/gtk.h> > > > #include <stdlib.h> > > > #include <stdio.h> > > > #include <time.h> > > > #include <string.h> > > > > > > //---------------------------------------------------------------------- > > > // run_btn_callback > > > // > > > // Try to run something in the background > > > // > > > //---------------------------------------------------------------------- > > > static void run_btn_callback (GtkWidget *button, gpointer data) > > > { > > > > > > int loops_to_run = 0; > > > int i = 0; > > > int pid = -1; > > > int ret = -1; > > > > > > // Skriv ut innehållet på skärmen > > > printf("Clicked..\n"); > > > printf("Data was: %s\n", gtk_entry_get_text( data )); > > > > > > loops_to_run = atoi( gtk_entry_get_text(data)); > > > > > > // We dont want to wait very long... > > > if( loops_to_run > 60 ) > > > { > > > loops_to_run = 60; > > > printf("Adjusting to 60 loops...\n"); > > > } > > > printf("Loops to run: %d\n", loops_to_run ); > > > > > > > > > > > > printf("We make a daemon\n"); > > > if ( ( pid = fork() ) < 0 ) > > > { > > > // Something went wrong > > > printf("We could not fork.... just exit"); > > > exit(-1); > > > } > > > else if ( pid != 0 ) > > > { > > > > > > // This is the parent process > > > printf("The background process have pid: %d\n", pid); > > > return; > > > } > > > > > > // Quit gtk > > > gtk_main_quit(); > > > > > > // Become session leader > > > ret = setsid(); > > > if( ret == -1 ) > > > { > > > perror("We could not be session leader\n"); > > > exit(-1); > > > } > > > > > > // Set umask for safety > > > umask(0); > > > > > > // Set root dir > > > chdir("/"); > > > > > > > > > for( i = 0; i < loops_to_run; i++ ) > > > { > > > printf("We are running: %d\n", i ); > > > sleep(1); > > > } > > > > > > exit(0); > > > > > > } > > > > > > //---------------------------------------------------------------------- > > > // When we quit > > > //---------------------------------------------------------------------- > > > static void quit_callback() > > > { > > > gtk_main_quit (); > > > } > > > > > > > > > //---------------------------------------------------------------------- > > > // main > > > // > > > // Creates a gtk windows to specify how many loops > > > // the daemon should run. > > > // > > > //---------------------------------------------------------------------- > > > int > > > main (int argc, char **argv) > > > { > > > > > > GtkWidget *mainwin = 0L; > > > GtkWidget *number_entry = 0L; > > > GtkWidget *run_btn = 0L; > > > GtkWidget *vbox = 0L; > > > > > > /* Initialize i18n support */ > > > printf("Locale is: %s\n", gtk_set_locale () ); > > > > > > /* Initialize the widget set */ > > > gtk_init (&argc, &argv); > > > > > > /* Create the main window */ > > > mainwin = gtk_window_new (GTK_WINDOW_TOPLEVEL); > > > > > > /* Set up our GUI elements */ > > > vbox = gtk_vbox_new (FALSE, 0); > > > > > > number_entry = gtk_entry_new(); > > > > > > run_btn = gtk_button_new_with_label("Just run"); > > > > > > gtk_container_add (GTK_CONTAINER (mainwin), vbox); > > > gtk_box_pack_start (GTK_BOX (vbox), number_entry, TRUE, TRUE, 0); > > > gtk_box_pack_start (GTK_BOX (vbox), run_btn, TRUE, TRUE, 0); > > > > > > > > > // Function to call when main window is destroyed > > > g_signal_connect (G_OBJECT (mainwin), > > > "destroy", > > > GTK_SIGNAL_FUNC (quit_callback), > > > NULL); > > > > > > // Function to call when we click the button > > > g_signal_connect(GTK_OBJECT(run_btn), "clicked", > > > G_CALLBACK(run_btn_callback), > > > number_entry); > > > > > > /* Show the application window */ > > > gtk_widget_show_all (mainwin); > > > > > > /* Enter the main event loop, and wait for user interaction */ > > > gtk_main (); > > > > > > /* The user lost interest */ > > > return 0; > > > > > > } > > > > > > //------------------------------------------------------------------ > > > // END > > > //------------------------------------------------------------------ > > > > > > ---<snipp>--- > > > > > > _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
