1949910 - Crash in [@ mozilla::StaticPrefs::widget_windows_mica_popups]

Status: RESOLVED FIXED

(Core :: Widget: Win32, defect)

Description

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

7 crashes from 5 installs of Firefox 137.0a1 20250221095438 on Windows 11.

Crash report: https://crash-stats.mozilla.org/report/index/581dff01-c5a2-42ee-885b-350ab0250221

MOZ_CRASH Reason:

MOZ_DIAGNOSTIC_ASSERT(IsAtomic<bool>::value || NS_IsMainThread()) (Non-atomic static pref 'widget.windows.mica.popups' being accessed on background thread by getter)

Top 10 frames:

0  xul.dll  mozilla::StaticPrefs::widget_windows_mica_popups()  modules/libpref/init/StaticPrefList_widget.h:353
0  xul.dll  mozilla::widget::WinUtils::MicaPopupsEnabled()  widget/windows/WinUtils.cpp:2043
1  xul.dll  nsLookAndFeel::NativeGetColor(mozilla::StyleSystemColor, mozilla::ColorScheme...  widget/windows/nsLookAndFeel.cpp:192
2  xul.dll  nsXPLookAndFeel::GetUncachedColor(mozilla::StyleSystemColor, mozilla::ColorSc...  widget/nsXPLookAndFeel.cpp:998
2  xul.dll  nsXPLookAndFeel::GetColorValue(mozilla::StyleSystemColor, mozilla::ColorSchem...  widget/nsXPLookAndFeel.cpp:979
2  xul.dll  mozilla::LookAndFeel::GetColor(mozilla::StyleSystemColor, mozilla::ColorSchem...  widget/nsXPLookAndFeel.cpp:1371
3  xul.dll  mozilla::LookAndFeel::Color(mozilla::StyleSystemColor, mozilla::ColorScheme, ...  widget/LookAndFeel.h:447
3  xul.dll  Gecko_ComputeSystemColor(mozilla::StyleSystemColor, mozilla::dom::Document co...  layout/style/GeckoBindings.cpp:754
4  xul.dll  style::gecko::media_queries::Device::system_nscolor(style::values::specified:...  servo/components/style/gecko/media_queries.rs:510
4  xul.dll  style::values::specified::color::SystemColor::compute(style::values::computed...  servo/components/style/values/specified/color.rs:428

Comment 1

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 1949910 - Mica popups pref should be atomic. r=#win-reviewers

System colors can be queried off the main thread. All the other related
bits are handled correctly during the servo traversal, including adding
the preference callbacks.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/7c39a7af9f99
Mica popups pref should be atomic. r=win-reviewers,gstoll

Comment 3

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/7c39a7af9f99