[maemo-developers] C - Hildon - Memory usage

[From: Markku Vire]

Hi,

HildonFileChooser can temporarily allocate large amounts of memory.
This goes away after all references to the chooser are removed.

However, the heap can shrink only when the topmost allocation is free'd.
This means that

   XXX.....................Y

the last allocation (Y) is preventing the free memory between X and Y to
be released back to system. In your example you're leaking
chooser_filename. With enough bad luck it can keep your process from
freeing memory it doesn't need anymore...

However, the VMSize is *not* a good way to measure memory usage. You
should check private dirty memory instead.

Hope this helps,

-Markku-

David Hautbois wrote:
> Hi
> 
> I'm a newbie with C programming and make many errors with memory 
> management (memory allocation, freeing memory...).
> So, I'm aware about the memory used by my application.
> I play with "top" and see my application uses 100MB !!!
> I check my code and see the problem is here :
> 
> ********************************************************
> void kml_browse_btn_clicked ( GtkWidget * widget, gpointer data) {
> 
>     GtkWidget * HildonDialog;
>     HildonDialog = hildon_file_chooser_dialog_new(GTK_WINDOW(pKmlBoite), 
> GTK_FILE_CHOOSER_ACTION_SAVE);
>     getchar();
> 
>     if (gtk_dialog_run (GTK_DIALOG (HildonDialog)) == GTK_RESPONSE_OK) {
>         gchar *chooser_filename = gtk_file_chooser_get_filename 
> (GTK_FILE_CHOOSER (HildonDialog));
>         gtk_entry_set_text( GTK_ENTRY(LocaldirEntry), chooser_filename);
>     }
>     gtk_widget_destroy (HildonDialog);
>     (void) widget;
>     (void) data;
> }
> ******************************************************************
> 
> Before "HildonDialog = hildon......."
> My application uses 36Mb.
> After (getchar), it uses 100Mb !!!:
>    VmPeak:       92288 kB
>    VmSize:       92284 kB
>    VmLck:           0 kB
>    VmHWM:       12736 kB
>    VmRSS:       12736 kB
>    VmData:       67484 kB
>    VmStk:          84 kB
>    VmExe:          40 kB
>    VmLib:       13504 kB
>    VmPTE:          56 kB
> 
> 
> When, I validate the dialog windows, "gtk_widget_destroy" does not free 
> the memory.
> 
> The application always uses 100Mb.
> 
> I'm a newbie, but I think there is a problem....
> Some help is needed.
> 
> Thanks.
> 
> David.
>