1636147 - RuntimeService::CrashIfHanging reports dead workers as active

Status: RESOLVED FIXED

(Core :: DOM: Workers, defect, P2)

Description

[Yaron Tausky [:ytausky]]

As described here, RuntimeService::CrashIfHanging is reporting workers whose status is Dead as active, causing a lot of crash reports wrongly attributed to hanging workers.

Comment 1

[Yaron Tausky [:ytausky]]

Attachment: Bug 1636147 - Don't report dead workers as active r=#dom-workers-and-storage-reviewers

RuntimeService::CrashIfHanging uses RuntimeService's registry
to determine which workers are still active. This approach is
flawed because the registry is updated on the main thread, so if
the main thread is stuck somewhere, dead workers could be reported
as active.
This commit adds an additional check: if dispatching a Runnable
to a worker fails, it assumes that the worker is dead. This way
main thread hangs would not be reported as worker hangs.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e63c8298618e
Don't report dead workers as active r=dom-workers-and-storage-reviewers,sg,asuth

Comment 3

[Narcis Beleuzu [:NarcisB]]

https://hg.mozilla.org/mozilla-central/rev/e63c8298618e

Comment 4

[Yaron Tausky [:ytausky]]

Comment on attachment 9146492 [details]
Bug 1636147 - Don't report dead workers as active r=#dom-workers-and-storage-reviewers

Beta/Release Uplift Approval Request

• User impact if declined: None, this patch only influences the way a shutdown hang is reported to us.
• 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): This patch shouldn't be risky because it only touches code that gets executed once it's certain that we're going to crash.
• String changes made/needed:

Comment 5

[Pascal Chevrel:pascalc]

Comment on attachment 9146492 [details]
Bug 1636147 - Don't report dead workers as active r=#dom-workers-and-storage-reviewers

This is a P2/S4 bug, there is no end user benefit to uplifting this patch in 77. Since we are ending the beta cycle, the patch will be in 78 beta 1 in less than 2 weeks, so I don't think that there is a compelling reason to uplift it in our last beta, sorry.