opengl can crash as we probe it

[Antoine Martin]

Maybe add a opengl=failsafe mode and run the gl check in a subprocess so that we can continue without when it crashes:

$ ./xpra/client/gl/gl_check.py
Gtk-Message: 21:10:38.426: Failed to load module "canberra-gtk-module"
No OpenGL_accelerate module loaded: No module named OpenGL_accelerate
testing <class 'xpra.platform.xposix.gl_context.GLXContext'>
OpenGL Warning: Failed to connect to host. Make sure 3D acceleration is enabled for this VM.

$ echo $?
1

[Antoine Martin]

Mostly done in r20862 via a hidden "opengl-probe" subcommand.

The code can be more easily triggered with:

XPRA_OPENGL_FORCE_TIMEOUT=10

to make the probe command timeout

XPRA_OPENGL_FORCE_CRASH=1

to make the probe command segfault

With either of those commands, or a buggy driver that crashes (ie: virtualbox), the client will run with opengl disabled and the status of the probe will be shown on session info.

Still TODO:

• suppress some log output when probing
• fix python3 mode..
• more testing, especially platform testing
• maybe add a "opengl-test" subcommand that does a test render on an actual window?

[Antoine Martin]

Updates:

• r20874: re-probe in the client unless we had a timeout or crash, that way we can show the problem / greylist details in the user notification
• r20873: suppress logging, unless in debug mode (r20875)
• r20872: pyopengl vs accelerate version mismatch is now an error (known to cause crashes)
• r20870: preserve python interpreter version for subcommands, to ensure we test the same thing!
• r20876: python3 (refactoring)
• r20877: also run the test rendering pass
• r20878: makes 'probe' the default

Only one thing left: maybe remove some of the blacklisted drivers now that crashes during probing aren't fatal?

[Antoine Martin]

r20983 removes most drivers from the blacklist, the probing should still discard them if they really are buggy.

[Antoine Martin]

r21059 updates the default config object.

[totaamwin32]

Caused problems on win32 when we can't find the executable to use for probing, fixed in r21156.

[Antoine Martin]

Follow up: #2204 (via #2203)