#13 pixmap memory leak in X server

[Mike Wyer]

Gtk::Pixmaps don't appear to free up their allocated
memory in the X server until the program exits, even if
they are "destroy"ed while the program is running.

The following code will cause the X server to bloat
(RSS goes from 35M (inc 32M framebuffer), to 300M in
about 30s). Just give it a filename for a picture (any
old jpeg will do).

Obviously this only affects code that creates and
destroys lots of pixmaps, but my little image browser
can easily crash the X server when it runs out of memory.

#!/usr/bin/env ruby

require 'gtk'
require 'gdk_pixbuf'

im = Gdk::Pixbuf.new(ARGV[0])
window = Gtk::Window.new(Gtk::WINDOW_TOPLEVEL)
frame = Gtk::Frame.new("Mem leak test")
widget = Gtk::Pixmap.new(*im.to_pixmap_and_mask)
frame.add widget.show
window.add frame.show
window.show
count = 1
Gtk::timeout_add(100) do
tmp = frame.child
if tmp
frame.remove tmp
tmp.destroy
GC.start
end
widget = Gtk::Pixmap.new(*im.to_pixmap_and_mask)
frame.add widget.show
count +=1
count <= 50
end

Gtk.main

[Masao Mutoh]

Logged In: YES
user_id=495147

Hi,

Thanks for your reporting.

This problem is caused that Gdk::Pixbuf#to_pixmap_and_mask
returns the copied Gdk::Pixmap/Gdk::Bitmap and which aren't
free when GC is called.

I think this is a serious bug, but it is difficult to fix
this with Ruby/GTK's current memory management system.
And I don't have enough times to fix this problem now....

If you can use Ruby/GTK2, please try Ruby/GTK2
as this problem has already fixed.

Or try a workarround as follows.

> #!/usr/bin/env ruby
>
> require 'gtk'
> require 'gdk_pixbuf'
>
> im = Gdk::Pixbuf.new(ARGV[0])
> window = Gtk::Window.new(Gtk::WINDOW_TOPLEVEL)
> frame = Gtk::Frame.new("Mem leak test")

pixmap, mask = im.to_pixmap_and_mask
widget = Gtk::Pixmap.new(pixmap, mask)

> frame.add widget.show
> window.add frame.show
> window.show
> count = 1
> Gtk::timeout_add(100) do
> tmp = frame.child
> if tmp
> frame.remove tmp
> tmp.destroy
> GC.start
> end

widget = Gtk::Pixmap.new(pixmap, mask)

> frame.add widget.show
> count +=1
> count <= 50
> end
>

Thanks,
Masao