The compositor report doesn't work on the virtual platform

[AlanGriffiths]

With ppa:mir-team/dev, running glmark2-wayland against the server before stopping it:

virtual

$ env -u DISPLAY WAYLAND_DISPLAY=wayland-1 mir_demo_server --virtual-output=1280x1020 --compositor-report=log | grep compositor:
[2023-10-26 14:09:53.575577] <information> compositor: Started
[2023-10-26 14:10:18.414969] <information> compositor: Stopped

X11

$ WAYLAND_DISPLAY=wayland-1 cmake-build-clang/bin/mir_demo_server --compositor-report=log | grep compositor:
[2023-10-26 14:10:29.998342] <information> compositor: Started
[2023-10-26 14:10:30.003047] <information> compositor: Added display 0x7f62880328c0: 1280x1024 +0+0
[2023-10-26 14:10:30.003182] <information> compositor: Display 0x7f62880328c0 bypass OFF
[2023-10-26 14:10:38.214326] <information> compositor: Display 0x7f62880328c0 averaged 62.510 FPS, 15.822 ms/frame, latency 0.747 ms, 63 frames over 1.007 sec, 0% bypassed
[2023-10-26 14:10:39.215458] <information> compositor: Display 0x7f62880328c0 averaged 59.932 FPS, 16.522 ms/frame, latency 0.894 ms, 60 frames over 1.001 sec, 0% bypassed
[2023-10-26 14:10:40.218146] <information> compositor: Display 0x7f62880328c0 averaged 59.839 FPS, 16.487 ms/frame, latency 1.139 ms, 60 frames over 1.002 sec, 0% bypassed
[2023-10-26 14:10:43.208538] <information> compositor: Stopped

[Saviq]

Hmm did we?

$ snap list mir-test-tools
Name            Version                Rev    Tracking  Publisher       Notes
mir-test-tools  2.15.0+dev374-snap155  12953  22/edge   alangriffiths✪  -

$ WAYLAND_DISPLAY=wayland-99 mir-test-tools.demo-server --compositor-report=log | grep compositor:
[2023-10-26 13:50:57.500680] < -warning- > miral: Failed to load cursor theme: default
[2023-10-26 13:50:57.511759] <information> compositor: Started
[2023-10-26 13:50:57.515811] <information> compositor: Added display 0x7fecc804ece0: 1280x1024 +0+0
[2023-10-26 13:50:57.515902] <information> compositor: Display 0x7fecc804ece0 bypass OFF
[2023-10-26 13:50:58.696504] <information> compositor: Stopped

Though #3086 does sound like it could affect that, if there wasn't anything to composite?

[Saviq]

Ah but yes, on the virtual platform we did:

WAYLAND_DISPLAY=wayland-99 MIR_SERVER_PLATFORM_DISPLAY_LIBS=mir:virtual MIR_SERVER_VIRTUAL_OUTPUT=1280x1024 ./build-Debug/bin/mir_demo_server --compositor=log | grep compositor

[2023-10-26 15:05:54.414189] <information> compositor: Started
^C

[AlanGriffiths]

Yeah

[RAOF]

This is the behaviour I expect - the virtual platform provides no DisplayBuffers, so no DisplayBufferCompositors are constructed, and so the compositor log (correctly) doesn't report any Compositor behaviour.

You get output from the virtual platform purely from the screencast infrastructure, which doesn't have a report.

[AlanGriffiths]

Obvious, once you point it out.