1600824 - PeerConnnection's operations chain should run synchronous parts of operations synchronously.

Status: RESOLVED FIXED

(Core :: WebRTC: Signaling, defect, P2)

Description

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

The way our peer connection operations chain works is a bit unfortunate, always awaiting a promise, causing code that according to spec should run synchronously to run on the microtask queue. Also, a few up-front uses of Promise.all cause the same thing.

Probably not a big difference, since it's still in the same run of the event loop. But it's JS observable to some extent, so I think we can fix this up a bit.

I ran into this while trying to write an isOperationsChainEmpty() detector to help write some wpt tests to investigate some timing issues in Chrome.

Am adding those tests here as well.

Comment 1

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

Attachment: Bug 1600824 - Fix operations queue to run 1st operation synchronously.

Comment 2

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

Any idea what might be happening here?

Comment 3

[Byron Campen [:bwc]]

Maybe you're tripping over bug 1591199 here (because the signalingstatechange event fires at the wrong time)?

Comment 4

[Jan-Ivar Bruaroey [:jib] (needinfo? me)]

Attachment: Bug 1600824 - Fix racy test_peerConnection_setLocalOfferInHaveRemoteOffer.html

Depends on D55585

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ee9a06cf6483
Fix operations queue to run 1st operation synchronously. r=bwc
https://hg.mozilla.org/integration/autoland/rev/d02d1c8a0b5c
Fix racy test_peerConnection_setLocalOfferInHaveRemoteOffer.html r=bwc

Comment 6

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/22029 for changes under testing/web-platform/tests

Comment 7

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream web-platform-tests status checks passed, PR will merge once commit reaches central.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/99bd31409968
Update expectation for RTCPeerConnection-operations.https.html. a=test-only

Comment 9

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/ee9a06cf6483
https://hg.mozilla.org/mozilla-central/rev/d02d1c8a0b5c
https://hg.mozilla.org/mozilla-central/rev/99bd31409968

Comment 10

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot