Hi Emanuelle, 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?
-Jonas 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 > > > > > > > > > > > > _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
