Hi; On 3 August 2016 at 15:37, Jonas <legojo...@gmx.de> wrote: > Hello Emmanuele, > > I reran my code, looked a bit at the archives (especially your answer > to a question about a potential memory leak of gtk_widget_destroy() > https://mail.gnome.org/archives/gtk-list/2008-September/msg00108.html) > and here's where I am now: > - not only the test program for the dialog increases in memory usage > over time but also the one for the window. I assume this is because > they're both toplevel.
Yep. > - since I don't think that my code is faulty, is it correct to assume > that the GSlice allocator simply doesn't really release the memory I > requested until the end of program runtime? The slice allocator will reuse freed slices of memory, if it can. If you keep allocating stuff in a tight loop it may end up with a larger slice of allocated memory before going back into the available slices and recycle the memory. That's why I said that top is not a memory measurement tool. If you want to check for leaks, use Valgrind — and read these links before doing that: * https://wiki.gnome.org/Valgrind * https://mail.gnome.org/archives/gtk-devel-list/2016-August/msg00000.html Ciao, Emmanuele. > On Wed, 2016-08-03 at 12:44 +0100, Emmanuele Bassi wrote: >> Hi; >> >> you should probably search the archives of this very mailing list, as >> this question has been asked countless times. >> >> The tl;dr is: >> >> * GObject uses a slab allocator, not the system one >> * top is not a memory profiling tool >> * if you keep things running in a tight loop you don't give GTK any >> chance to actually release memory >> * gtk_widget_destroy() is not the equivalent of free() >> >> Ciao, >> Emmanuele. >> >> >> On 3 August 2016 at 12:24, Jonas <legojo...@gmx.de> wrote: >> > Hello everyone, >> > >> > I have a question about a memory leak I seem to have with >> > GtkDialog. I >> > already posted this on DreaminCode (username Progammer) and decided >> > to >> > ask the same question on the mailing lists here. Here it is: >> > >> > "[...]I looked at the Gtk and GObject Documentation and figured out >> > the >> > following from Gtk Common Question 1.5, GObject Manual and the >> > gtk_widget_destroy() documentation: >> > >> > - GtkWidgets that are top-level windows are created with an initial >> > floating reference count of one, Gtk calls g_object_ref_sink() to >> > acquire the reference and keeps the window in its list of top >> > -levels. >> > - all other GtkWidgets (e.g. buttons) are created with a floating >> > reference count of one. Packing the widget into a container makes >> > the >> > container own the reference (the container calls g_object_ref_sink >> > on >> > the widget). Simply calling g_object_ref_sink on your own makes >> > your >> > own code acquire the initial reference. >> > - destroying widgets: gtk_widget_destroy breaks references the >> > widget >> > holds to other widgets, packed widgets are removed from their >> > containers (decrementing the widget's reference count) and top >> > -level >> > windows are removed from Gtks list of top-levels (also decrementing >> > the >> > reference count). >> > - when the reference count of an object drops to 0, the object is >> > finalized and it's memory is freed >> > - GtkWindow is a GtkWidget is a GInitiallyUnowned is a GObject >> > (shortened hierarchy) >> > >> > I wrote the following three programs to demonstrate memory >> > management >> > of GtkButton, GtkWindow and GtkDialog: >> > -- as far as I see it, GtkDialog is derived from GtkWindow and is >> > therefore a top-level and kept in Gtks list of top-levels. Please >> > correct me if I'm wrong ;) -- >> > >> > GtkButton: >> > >> > #include <gtk/gtk.h> >> > >> > int main (int argc, char *argv[]) >> > { >> > gtk_init( &argc, &argv ); >> > >> > GtkWidget *button; >> > do >> > { >> > button = gtk_button_new(); //create with floating ref >> > count of >> > one >> > g_object_ref_sink(button); //acquire the initial floating >> > reference (ref count is now 0 and non-floating) >> > gtk_widget_destroy(button); //break external references >> > g_object_unref(button); //release my reference >> > (reference >> > count drops to 0, the widget's memory is freed) >> > printf("Destroyed\n"); >> > } >> > while(getchar() != 'Q'); >> > >> > return 0; >> > } >> > >> > >> > GtkWindow: >> > >> > #include <gtk/gtk.h> >> > >> > int main (int argc, char *argv[]) >> > { >> > gtk_init( &argc, &argv ); >> > >> > GtkWidget *window; >> > do >> > { >> > window = gtk_window_new(GTK_WINDOW_TOPLEVEL); //create >> > window, >> > gtk will add it to it's list of top-levels and acquire ownership of >> > the >> > initial reference. >> > gtk_widget_destroy(window); //break references the window >> > holds to other objects, remove window from gtk's list of toplevels. >> > Window is finalized (memory is freed). >> > printf("Destroyed\n"); >> > } >> > while(getchar() != 'Q'); >> > >> > return 0; >> > } >> > >> > GtkDialog: >> > >> > #include <gtk/gtk.h> >> > >> > int main (int argc, char *argv[]) >> > { >> > gtk_init( &argc, &argv ); >> > >> > GtkWidget *dialog; >> > do >> > { >> > dialog = gtk_dialog_new(); //create dialog, add to list >> > of >> > top-levels >> > gtk_widget_destroy(dialog); //break references it holds, >> > remove from list of top-levels, finalizing dialog and freeing >> > memory (I >> > thought :D) >> > printf("Destroyed\n"); >> > } >> > while(getchar() != 'Q'); >> > >> > return 0; >> > } >> > >> > >> > For all three programs, a widget is created and destroyed and when >> > the >> > user hits the Return key and 'Q' was not pressed right before, it's >> > done again. >> > >> > What I expected to happen: >> > - Memory usage of all three programs should stay the same even when >> > I >> > hit the Return key a hundred to a thousand times or more. >> > >> > What really happened: >> > - the memory usage did not go up for the program with the GtkButton >> > and >> > the program with the GtkWindow. >> > - for the program with the GtkDialog, the memory usage went up >> > every >> > time I hit the return key. >> > >> > Why is this happening? I thought GtkDialog would behave the same as >> > GtkWindow in terms of memory management since it's derived from it. >> > >> > I hope anyone knows what is going on here :)" - Progammer on >> > http://www >> > .dreamincode.net/forums/topic/395882-trouble-with-gtkdialog-memory >> > -management/ (August 3rd 2016, 11:23 GMT) >> > >> > >> > Does anyone of you know why this is? >> > >> > Jonas Fuglsang-Petersen >> > _______________________________________________ >> > gtk-app-devel-list mailing list >> > gtk-app-devel-list@gnome.org >> > https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list >> >> >> -- https://www.bassi.io [@] ebassi [@gmail.com] _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
