commit ca57ed45a51d65ecda7b4e74575da249480a9f86
author Miguel Casas <mcasas@chromium.org> Wed Jan 03 20:20:36 2024
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Wed Jan 03 20:20:36 2024
tree 61aaffc0f6f36c2c29931f846882eb6271370102
parent f78af41545dfeec591636ce45abf8fb1cfffe69b

media/gpu/v4l2: Allow V4L2DevicePoller blocking behaviour

V4L2DevicePoller has two problem re. threading:
- One is that it calls Stop() on an internal thread [1], which
violates AssertBaseSyncPrimitivesAllowed()[2] (because Stop() is
blocking).
- Another is that the member thread uses Wait() [3] and Poll() [4]
(both of which are blocking) on that internal Thread that is constructed as non blockable (and this can't be tweaked BTW).

Fixing V4L2DevicePoller would be risky and complicated, and it's
anyway going to be deprecated (I estimate in the next 6 months or
so). This CL explicitly allows for the blocking behaviour.

[1] https://source.chromium.org/chromium/chromium/src/+/main:media/gpu/v4l2/v4l2_device_poller.cc;l=85;drc=d70f89acd09b75f61ae0d18689737246eca6c499
[2] https://source.chromium.org/chromium/chromium/src/+/main:base/threading/thread_restrictions.cc;l=160-170;drc=9a4c11173d5209a3b813c746e342155896738eb3
[3] https://source.chromium.org/chromium/chromium/src/+/main:media/gpu/v4l2/v4l2_device_poller.cc;l=120;drc=d70f89acd09b75f61ae0d18689737246eca6c499

Bug: b:314147674, 1513721
Change-Id: I40dce642b078a741ab7791c9d288bfdbca57b450
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5142394
Reviewed-by: Fritz Koenig <frkoenig@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Commit-Queue: Miguel Casas-Sanchez <mcasas@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1242591}