The stuff in MediaDecoderStateMachine::SetStateMachineParameters accounts for a lot of remaining cross-thread access, and is ripe for mirroring.

There are a handful of methods where we can't yet assert this. This bug will tackle several of them.

While we're at it, I figured it was time to experiment with lambdas. :-)

Comment on attachment 8600630 [details] [diff] [review] Part 6 - Dispatch SetMinimizePrerollUntilPlabackStarts. v1 Review of attachment 8600630 [details] [diff] [review]: ----------------------------------------------------------------- ::: dom/media/MediaDecoderStateMachine.h @@ +409,5 @@ > + self->mMinimizePreroll = true; > + > + // Make sure that this arrives before playback starts, otherwise this won't > + // have the intended effect. > + MOZ_DIAGNOSTIC_ASSERT(self->mPlayState != MediaDecoder::PLAY_STATE_PLAYING); Shouldn't we assert |mPlayState == MediaDecoder::PLAY_STATE_LOADING| which is the initial state? However, we must be wary of the ordering issue where this lambdas must be run before self->mPlayState is updated from the canonical value. Can we also mirror mMinimizePreroll to free from the worries?

(In reply to JW Wang [:jwwang] from comment #9) > Shouldn't we assert |mPlayState == MediaDecoder::PLAY_STATE_LOADING| which > is the initial state? Sure. > However, we must be wary of the ordering issue where > this lambdas must be run before self->mPlayState is updated from the > canonical value. Can we also mirror mMinimizePreroll to free from the > worries? I considered doing that, but mirroring seems like overkill given the current code. Moreover, I don't think it would actually help, because we don't have logic to handle preroll-minimization-after-play. The assert should tell us if it's ever a problem.

https://hg.mozilla.org/integration/mozilla-inbound/rev/3188222d0682 https://hg.mozilla.org/integration/mozilla-inbound/rev/41b7be6965cd https://hg.mozilla.org/integration/mozilla-inbound/rev/9b076e62f534 https://hg.mozilla.org/integration/mozilla-inbound/rev/007ffa56b3da https://hg.mozilla.org/integration/mozilla-inbound/rev/14a22fe5a081 https://hg.mozilla.org/integration/mozilla-inbound/rev/bc2c1323e336

https://hg.mozilla.org/mozilla-central/rev/3188222d0682 https://hg.mozilla.org/mozilla-central/rev/41b7be6965cd https://hg.mozilla.org/mozilla-central/rev/9b076e62f534 https://hg.mozilla.org/mozilla-central/rev/007ffa56b3da https://hg.mozilla.org/mozilla-central/rev/14a22fe5a081 https://hg.mozilla.org/mozilla-central/rev/bc2c1323e336