Is this a memory leak issue or something else?

[aykaramba]

Code:

(defpackage :test (:use :cl :sketch))
(in-package :test)

(defsketch test ((title "test")
                 (size-scale 1)
                 (color-start 0)
                 (height 400)
                 (width 400))
    (let ((cv (make-canvas 400 400)))
         (canvas-paint cv +blue+ 0 0)
         (canvas-paint cv +red+ 0 1)
         (canvas-paint cv +green+ 1 0)
         (canvas-paint cv +black+ 1 1)
      
         (canvas-paint cv +orange+ 2 0)
         (canvas-paint cv +red+ 2 1)
         (canvas-paint cv +blue+ 2 2)

         (canvas-paint cv +green+  1 2)
         (canvas-paint cv +yellow+ 9 9)
         (canvas-paint cv +yellow+ 199 199)
         (canvas-paint cv +yellow+ 399 399)

         (canvas-lock cv)
         (let ((draw-size (* size-scale 400)))
              (draw cv :width draw-size 
                              :height draw-size
                              :min-filter :linear 
                              :mag-filter :linear))))

(make-instance 'test)

I am playing around with sketch and learning canvas. The above code just tries to open a 400x400 window, draw a canvas in it and colour a few pixels just to test.

PROBLEM: I have htop open and the above main (let (())) form starts consuming ram really really quickly.

Is that a memory leak or an issue with the code? It feels like the moment I uncomment the let form and ram starts growing really quickly that the rendering is being done in an additive way instead of overwriting the previous frame like (rectangle 10 10 50 50) would do.

Thoughts or suggestions?

Thanks.

[Kevinpgalligan]

It might be that the canvas is being reallocated on every loop and is not getting cleaned up. I'll have to check, I forget how the memory management works there

[Kevinpgalligan]

I wonder if you'd have that issue if you created the canvas as a parameter of the sketch rather than in the drawing loop

[aykaramba]

That was quick! Let me check, interesting. Hmmm ...

[aykaramba]

Yup, that is what it was. This works:

(defpackage :test (:use :cl :sketch))
(in-package :test)

(defsketch test ((title "test")
                 (size-scale 1)
                 (color-start 0)
                 (height 400)
                 (width 400)
                 (cv (make-canvas 400 400)))

  (canvas-paint cv +blue+ 0 0)
  (canvas-paint cv +red+ 0 1)
  (canvas-paint cv +green+ 1 0)
  (canvas-paint cv +black+ 1 1)
      
  (canvas-paint cv +orange+ 2 0)
  (canvas-paint cv +red+ 2 1)
  (canvas-paint cv +blue+ 2 2)

  (canvas-paint cv +green+  1 2)
  (canvas-paint cv +yellow+ 9 9)
  (canvas-paint cv +yellow+ 199 199)
  (canvas-paint cv +yellow+ 399 399)

  (canvas-lock cv)
  (let ((draw-size (* size-scale 400)))
    (draw cv :width draw-size 
          :height draw-size
          :min-filter :linear 
          :mag-filter :linear)))

(make-instance 'test)

That is very interesting. I was not expecting that but it makes sense as we probably want to draw canvas once and update it all the time. Other operations just get redrawn every frame.

Interesting to know!

By the way, thank you very much for the canvas updates. This is very cool!

[Gleefre]

Actually, if you don't unlock the canvas before relocking it, the image won't be updated. I suspect that if you add a call to canvas-unlock in the draw loop, or remove the call to canvas-lock the problem might be back. I'm not sure, but it seems that the gl surface created in the call to canvas-image (when the canvas isn't locked - either during draw or canvas-lock) is never freed, not even after closing the sketch window (that's when all the loaded (from a file) resources are usually freed).

[aykaramba]

Okay, I will do more testing on this. I don't have the skills to debug the source but that makes more sense. Will update this after testing. Thanks.

[aykaramba]

You are right. The moment canvas-unlock is uncommented ram starts accumulating. Code:

(defpackage :test (:use :cl :sketch))
(in-package :test)

(defsketch test ((title "test")
                 (size-scale 1)
                 (color-start 0)
                 (height 400)
                 (width 400)
                 (cv (make-canvas 400 400)))

  (canvas-unlock cv)

  (canvas-paint cv +blue+ 0 0)
  (canvas-paint cv +red+ 0 1)
  (canvas-paint cv +green+ 1 0)
  (canvas-paint cv +black+ 1 1)
      
  (canvas-paint cv +orange+ 2 0)
  (canvas-paint cv +red+ 2 1)
  (canvas-paint cv +blue+ 2 2)

  (canvas-paint cv +green+  1 2)
  (canvas-paint cv +yellow+ 9 9)
  (canvas-paint cv +yellow+ 199 199)
  (canvas-paint cv +yellow+ 399 399)
 
  (let ((draw-size (* size-scale 400)))
       (draw cv :width draw-size 
                :height draw-size
                :min-filter :linear 
                :mag-filter :linear))

    (canvas-lock cv))

(make-instance 'test)