0.91ms uninterruptible reflow at waitForSyncCallback@resource://gre/modules/services-common/async.js:98:7

RESOLVED INVALID

Status

()

Firefox
Sync
RESOLVED INVALID
a year ago
11 months ago

People

(Reporter: Robbie Ward, Unassigned)

Tracking

(Blocks: 1 bug)

Firefox Tracking Flags

(Not tracked)

Details

(Whiteboard: [ohnoreflow][qf])

(Reporter)

Description

a year ago
Here's the stack:

waitForSyncCallback@resource://gre/modules/services-common/async.js:98:7
makeSpinningCallback/callback.wait@resource://gre/modules/services-common/async.js:168:27
promiseSpinningly@resource://gre/modules/services-common/async.js:234:12
_fetchServerConfiguration@resource://services-sync/service.js:855:24
_remoteSetup@resource://services-sync/service.js:880:10
sync@resource://services-sync/stages/enginesync.js:86:11
onNotify@resource://services-sync/service.js:1080:7
WrappedNotify@resource://services-sync/util.js:161:21
WrappedLock@resource://services-sync/util.js:117:16
_lockedSync@resource://services-sync/service.js:1070:12
sync/<@resource://services-sync/service.js:1062:7
WrappedCatch@resource://services-sync/util.js:92:16
sync@resource://services-sync/service.js:1051:5
Component: Untriaged → Sync
huh - this stack points at a nested event loop we spin (yeah, I know, bug 1007448) while waiting for an async network fetch and getting a tiny response. Is it possible these nested event loops are causing mis-attribution? Eg, we have issues with the profiler/debugger in that any code run indirectly via that event loop looks like it comes from sync, and while this looks a bit different to that, it might still be a complication.
Flags: needinfo?(rjward0)
Flags: qe-verify?
Priority: -- → P2
Blocks: 1348289
No longer blocks: 1363750
Oh no! Reflow! can't tell the difference between a JS-caused reflow, and a reflow that's occurring natively while spinning a nested event loop in JS, which I think is what's happening here.

I'll see if I can alter Oh no! Reflow! to detect this difference, but for now, closing this as INVALID.
Status: NEW → RESOLVED
Last Resolved: 11 months ago
Resolution: --- → INVALID

Updated

11 months ago
Flags: qe-verify?
Priority: P2 → --
Whiteboard: [ohnoreflow][qf][photon-performance] → [ohnoreflow][qf]
(Reporter)

Updated

11 months ago
Flags: needinfo?(rjward0)
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