Hi; On 3 August 2016 at 17:54, Jonas <legojo...@gmx.de> wrote:
> Thanks for the info about the slice allocator, I think that'll be good > for my purposes. As for valgrind and the suppression files, I tried a > few, it's too bad that it's hard to differentiate between actual memory > leaks and the ones that valgrind shows as leaks... Do you have any > other suppression file that might do a good job? The link to the email thread I gave you should have more information on suppression files. Ciao, Emmanuele. > On Wed, 2016-08-03 at 15:48 +0100, Emmanuele Bassi wrote: >> 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.ht >> > ml) >> > 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/msg000 >> 00.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
