Re: memory leak, destroying widgets

From: "Jacques Le Normand" <[email protected]>

> I'm getting a memory leak in my program because, when I destroy a widget,
> the memory does not get freed. I thought it would be done automatically when
> I call #remove from the container, but this does not seem to be the case.
> How can I destroy my widgets and make sure the memory is cleared? I've tried
> 2 or 3 different ways, with the same result.

You should use Gc.full_major, to ensure that all finalizers are
called.
Note however that, in byte code, a variable referenced in the
environment (either function argument or let-definition) cannot be
freed until you leave the function.
It should be ok to add a Gc.full_major call in your timeout.

Jacques


> Here is a program that creates and destroys 100 GEdit.entry every 200ms. At
> every iteration, I call  Gc.allocated_bytes . The number printed keeps going
> up (showing that there is a memory leak.) I posted it a week ago. I've
> gotten a couple of people to run it and they all get the same result. If
> more people could run it to make sure, that would be greatly approciated.
> cheers
> --Jacques
> 
> 
> let repeat n f =
>   let rec rep i =
>     if i = n then [] else (f () :: rep (i+1))
>   in
>     rep 0
> 
> 
> let container_clear c =
>   List.iter c#remove c#all_children
> 
> let _ =
>   let source_window = GWindow.window ~width:100 ~height:100 () in
>   let vbox = GPack.vbox ~packing:source_window#add () in
>   let inside = ref false in
>   let fill_vbox () =
>     if !inside then
>       ()
>     else
>       begin
>     inside := true;
>     let add_entry () =
>       let ret = GEdit.entry ()
>       in
>         vbox#pack (ret:>GObj.widget);
>         ret
>     in
>       container_clear vbox;
>       print_endline (string_of_float  (Gc.allocated_bytes ()));
>       ignore(repeat 100 add_entry);
>       inside:=false
>       end
>   in
>     ignore(Glib.Timeout.add 200 (fun () -> fill_vbox (); true));
>     source_window#show ();
>     GMain.Main.main ()