[PATCH] gtkagg backend leaks gc's.

Hello,

I noticed that a program I had that uses canvas.blit() to do animated graphs with the gtkagg backend was leaking memory.

I tracked this down to gtk gc's being allocated in agg_to_gtk_drawable with gdk_gc_new(), but never being destroyed.

The leak can be seen using the 'Animating selected plot elements' example from:

http://www.scipy.org/Cookbook/Matplotlib/Animations

(if it is modified to run forever, rather than just 50 plots and also changing numerix to numpy). After a few minutes, it is clear from ps that the memory usage is slowly but steadily climbing.

Patch below (against matplotlib-1.1.1.) fixes it.

Carl

--- _gtkagg.cpp~ 2012-06-30 12:37:00.000000000 -0700
+++ _gtkagg.cpp 2012-11-08 14:30:23.000000000 -0800
@@ -121,6 +121,7 @@
                                  destbuffer,
                                  deststride);

+ gdk_gc_destroy(gc);
            if (needfree)
            {
                delete [] destbuffer;

If you are willing, would you like to file a PR against the v1.2.x branch?

Ben Root

···

On Thursday, November 8, 2012, Carl Michal wrote:

Hello,

I noticed that a program I had that uses canvas.blit() to do animated graphs

with the gtkagg backend was leaking memory.

I tracked this down to gtk gc’s being allocated in agg_to_gtk_drawable with

gdk_gc_new(), but never being destroyed.

The leak can be seen using the ‘Animating selected plot elements’ example

from:

http://www.scipy.org/Cookbook/Matplotlib/Animations

(if it is modified to run forever, rather than just 50 plots and also

changing numerix to numpy). After a few minutes, it is clear from ps that the

memory usage is slowly but steadily climbing.

Patch below (against matplotlib-1.1.1.) fixes it.

Carl

— _gtkagg.cpp~ 2012-06-30 12:37:00.000000000 -0700

+++ _gtkagg.cpp 2012-11-08 14:30:23.000000000 -0800

@@ -121,6 +121,7 @@

                              destbuffer,

                              deststride);
  •   gdk_gc_destroy(gc);
    
          if (needfree)
    
          {
    
              delete [] destbuffer;
    

Decided to follow-up on this and it looks like this patch has already
been applied.

···

On Sun, Nov 11, 2012 at 4:23 PM, Benjamin Root <ben.root@...553...> wrote:

On Thursday, November 8, 2012, Carl Michal wrote:

Hello,

I noticed that a program I had that uses canvas.blit() to do animated
graphs
with the gtkagg backend was leaking memory.

I tracked this down to gtk gc's being allocated in agg_to_gtk_drawable
with
gdk_gc_new(), but never being destroyed.

The leak can be seen using the 'Animating selected plot elements' example
from:

http://www.scipy.org/Cookbook/Matplotlib/Animations

(if it is modified to run forever, rather than just 50 plots and also
changing numerix to numpy). After a few minutes, it is clear from ps that
the
memory usage is slowly but steadily climbing.

Patch below (against matplotlib-1.1.1.) fixes it.

Carl

--- _gtkagg.cpp~ 2012-06-30 12:37:00.000000000 -0700
+++ _gtkagg.cpp 2012-11-08 14:30:23.000000000 -0800
@@ -121,6 +121,7 @@
                                  destbuffer,
                                  deststride);

+ gdk_gc_destroy(gc);
            if (needfree)
            {
                delete [] destbuffer;

If you are willing, would you like to file a PR against the v1.2.x branch?

Ben Root

--
Damon McDougall
http://www.damon-is-a-geek.com
Institute for Computational Engineering Sciences
201 E. 24th St.
Stop C0200
The University of Texas at Austin
Austin, TX 78712-1229