1174018 - [EME][GMP] Too many video elements in EME tests cause timeouts

Status: NEW

(Core :: Audio/Video: Playback, defect, P3)

Description

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Spawned from bug 1138294 comment 22.

Adding more test cases to EME tests cause timeouts in test_eme_stream_blocked, which seem to be due to having lots of video elements hanging around and hogging resources, especially on the Windows plugin side, which accumulates 10 threads per video; i.e., a test case load of 140 videos creates about 1400 threads!

At some point (depending on machine resources: in my tests 18 on try-win32, 140 on local win64 VM), something locks up and we never get the expected 'loadeddata' event. The real cause is not known yet; it could be down to messaging, the plugin not being able to process incoming messages anymore, the parent getting into some unknown state, or something else.

Latest try with as much logging as possible:
https://treeherder.mozilla.org/#/jobs?repo=try&revision=820c74ebbbcf
Local test with even more printf's:
https://etherpad.mozilla.org/8edbPh3HwZ

Comment 1

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Note: Future Media plans include having a maximum number of decoders at any time, so then we may not run into a similar issue where a huge number of decoders get instantiated.

Comment 2

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

De-assigning myself from A/V bugs/tasks that I most probably won't touch anymore, so that someone else may have a look.