1539030 - Don't call RDDProcessManager::CreateContentBridge unless a new process is actually launched

Status: RESOLVED FIXED

(Core :: Audio/Video: Playback, enhancement, P2)

Description

[Michael Froman [:mjf]]

We're calling RDDProcessManager::CreateContentBridge even if we've already launched the RDD processs which is causing churn by recreating RemoteDecoderManagerParents.

I'm hoping this is the cause of Bug 1535335, but I'm not certain. I want to land this fix and watch the crash stats.

Comment 1

[Michael Froman [:mjf]]

Attachment: Bug 1539030 - Don't RDDProcessManager::CreateContentBridge unless needed. r?jya!

We were calling RDDProcessManager::CreateContentBridge even if we'd
already launched the RDD process.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a0bed49e8b10
Don't RDDProcessManager::CreateContentBridge unless needed. r=jya

Comment 3

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/a0bed49e8b10

Comment 4

[Michael Froman [:mjf]]

When I fixed 1540587, the fix was backing out the changes made in this bug completely. I have a more complete fix now so I'm going to reopen this bug.

Comment 5

[Michael Froman [:mjf]]

Attachment: Bug 1539030 - (redux) don't attempt RDD launch unless needed. r?jya

Detect content process that already has connection to the RDD process
and don't attempt to relaunch or needlessly call
RDDProcessManager::CreateContentBridge. Calling CreateContentBridge
unnecessarily causes churn by recreating RemoteDecoderManagerParents.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/6638560366c4
(redux) don't attempt RDD launch unless needed. r=jya

Comment 7

[Raul Gurzau (:RaulG)]

https://hg.mozilla.org/mozilla-central/rev/6638560366c4

Comment 8

[Michael Froman [:mjf]]

Comment on attachment 9061011 [details]
Bug 1539030 - (redux) don't attempt RDD launch unless needed. r?jya

Beta/Release Uplift Approval Request

• User impact if declined: This patch reduces RDD initialization churn that could result in content process crash resembling Bug 1535335.
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Small changes in RemoteDecoderModule.{h|cpp} that only affect RDD re-initialization make this low risk.
• String changes made/needed: n/a

Comment 9

[Pascal Chevrel:pascalc (PTO until April 26)]

Comment on attachment 9061011 [details]
Bug 1539030 - (redux) don't attempt RDD launch unless needed. r?jya

Fix a P2 but has no bake time on nightly and the volume of crashes it may fix is low. Given that we have already shipped our last beta, I think the risk is bigger than the potential reward so I am not taking the uplift, sorry.