possible memory leaks in the OpenGL plugin

[Daniel Koukola]

It looks like that objects allocated inside GLWindow::addShaders and GLVertexBuffer::addUniform methods are never deleted.

I'm using a plugin (compiz-cms) that uses both those methods and it leaks memory very fast:

==21530== 24,821,632 (10,638,048 direct, 14,183,584 indirect) bytes in 443,252 blocks are definitely lost in loss record 1,143 of 1,145
==21530== at 0x4A068F3: operator new(unsigned long) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==21530== by 0x6536B2C: GLVertexBuffer::addUniform(char const*, int) (in /usr/lib64/compiz/libopengl.so)
==21530== by 0xC351FFB: CmsWindow::glDrawTexture(GLTexture*, GLMatrix const&, GLWindowPaintAttrib const&, unsigned int) (cms.cpp:530)
==21530== by 0x652F030: GLWindow::glDrawTexture(GLTexture*, GLMatrix const&, GLWindowPaintAttrib const&, unsigned int) (in /usr/lib64/compiz/libopengl.so)

==21530== 128,089,075 (10,638,072 direct, 117,451,003 indirect) bytes in 443,253 blocks are definitely lost in loss record 1,145 of 1,145
==21530== at 0x4A068F3: operator new(unsigned long) (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==21530== by 0x653872D: GLWindow::addShaders(std::string, std::string, std::string) (in /usr/lib64/compiz/libopengl.so)
==21530== by 0xC351F8E: CmsWindow::glDrawTexture(GLTexture*, GLMatrix const&, GLWindowPaintAttrib const&, unsigned int) (cms.cpp:529)
==21530== by 0x652F030: GLWindow::glDrawTexture(GLTexture*, GLMatrix const&, GLWindowPaintAttrib const&, unsigned int) (in /usr/lib64/compiz/libopengl.so)

[MC Return (mc-return)]

Look like new without delete case bugs.

Thanks 4 the detailed report. +1

Do you have a patch fixing the leaks also ?

[Daniel Koukola (dan-atrey)]

I'm afraid I don't understand that code well enough to fix it correctly. It seems that all uniforms could be deleted before deleting or clearing the container that contains them. But for shaders that doesn't work as some of them come from the shader cache (auto program?) and those shouldn't be deleted.

[Daniel Koukola (dan-atrey)]

Attached a quick fix. But maybe it would be better to use boost::shared_ptr?

[MC Return (mc-return)]

Daniel, thanx a lot 4 your patch. Looks good to me at first glance.

You do not need the brackets, if there is just one statement in the if condition/for loop though, but that is a minor coding style issue only...
Not sure about boost::shared_ptr and I am also not a shader expert, but I would say: "If your patch fixes the leaks without crashing the shader, all should be good." ;)
I will test your patch and report back, although I am not sure, if I am able to reproduce the leaks as just the "Negative" plugin seems to use GLWindow::addShaders.

If you have an improved version in the meantime, do not hesitate to post it here.

[Stephen M. Webb (bregma)]

The attached patch no longer applies but the leaks are still evident on inspection of the code.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "compiz-fix-opengl-leak.patch" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

[Launchpad Janitor (janitor)]

This bug was fixed in the package compiz - 1:0.9.12+15.04.20141031-0ubuntu1

---------------
compiz (1:0.9.12+15.04.20141031-0ubuntu1) vivid; urgency=low

  [ Stephen M. Webb ]
  * filter debian/ from upstream dist tarball (LP: #1075995)
  * removed distro-patch for #873384 because it's now upstream (LP:
    #873384)
  * removed inappropriate executable permissions from some source and
    data files (LP: #1086165)
  * window_decorator: renamed a local to unhide a parameter (LP:
    #957600)
  * opengl plugin: free shaders and uniforms (LP: #1227449)
  * debian/compizconfig: renamed from debian/config to avoid debconf
    clashes (LP: #1156294)
  * animation plugin: initialize mPrevAnimSelectionRow (LP: #1101630)

  [ Klaus Knopper ]
  * Forces non-opaque pointer in the ezoom plugin. (LP: #1362005)

  [ Henry Hu ]
  * place plugin: correct min and default placement modes in
    configuration

  [ Matija Skala ]
  * remove 'extern "C"' hack (LP: #1286562)

  [ Dariusz Gadomski ]
  * CompScreen: Save focused window id before changing viewport.
 -- Ubuntu daily release <email address hidden> Fri, 31 Oct 2014 17:03:50 +0000