flypig.co.uk

I'm working my way through the SharedSurface_EGLImage::Create() method and gradually increasing the steps that are executed. Over the last few days I first established that preventing the SurfaceFactory_EGLImage from being created was enough to prevent the app from seizing up. Without the factory the surfaces themselves weren't going to get created. Next I enabled the factory but disabled the image creation.

Today I'm allowing the offscreen texture to be created by allowing this call to take place:

  GLuint prodTex = CreateTextureForOffscreen(prodGL, formats, size);

But I've placed a return immediately afterwards so that neither the image nor the surface that builds on this are created. Once again the objective is to find out whether the app seizes up or not. If it does then that would point to the texture being the culprit. If not, it's likely something that follows it.

Change made, code built, binary transferred and library installed. Now running the app, there's no seizing up. So that takes us one more step closer to finding the culprit. Now I've moved the early return one step later, until after the EGLImage has been created using the texture, after these lines:

  EGLClientBuffer buffer =
      reinterpret_cast<EGLClientBuffer>(uintptr_t(prodTex));
  EGLImage image = egl->fCreateImage(context,
                                     LOCAL_EGL_GL_TEXTURE_2D, buffer, nullptr);
  if (!image) {
    prodGL->fDeleteTextures(1, &prodTex);
    return ret;
  }

Once again, I've build, transferred and installed the updated library. And now when I run it... the app seizes up! So we have our culprit. The problem seems to be the creation of the image from the surface that's either causing the problem in itself, or triggering something else to cause the problem. The most likely offender in the latter case would be if the created image weren't being freed:

  EGLImage image = egl->fCreateImage(context,
                                     LOCAL_EGL_GL_TEXTURE_2D, buffer, nullptr);

This is reminiscent of a problem I experienced earlier which resulted in me having to disable the texture capture for the cover image. Now that it's narrowed down I can look into the underlying reason. That will be my task for tomorrow morning.

If you'd like to read any of my other gecko diary entries, they're all available on my Gecko-dev Diary page.