2074009 - Add isDefaultBrowserAsync() to nsIShellService and migrate callers

Status: ASSIGNED

(Firefox :: Shell Integration, task)

Description

[Jan Varga [:janv]]

nsIShellService::isDefaultBrowser() is currently synchronous. On Linux, checking the default browser may involve D-Bus, so calling it synchronously on the main thread can block Firefox.

As a first step towards making the Linux implementation truly asynchronous, add an isDefaultBrowserAsync() API to nsIShellService and migrate as many consumers as practical to use it.

Initially, the async implementation can simply call the existing synchronous implementation and resolve the returned value immediately. This keeps the behavior unchanged while allowing callers to be converted to an async API.

In a follow-up, the Linux implementation can move the potentially blocking work off the main thread so that D-Bus access no longer blocks Firefox UI.

This bug should also update affected tests and mocks to support the new async API.

This blocks the broader bug 2044186 for making D-Bus-related internal APIs asynchronous.

Comment 1

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Clean up nsGNOMEShellService::IsDefaultBrowser(); r=#gtk-reviewers

Clean up nsGNOMEShellService::IsDefaultBrowser() in preparation for adding the
asynchronous implementation.

Comment 2

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Add isDefaultBrowserAsync() to nsIShellService; r=#firefox-desktop-core-reviewers,#gtk-reviewers

Add an asynchronous variant of isDefaultBrowser() to nsIShellService and expose
it through ShellService as well.

For now, the platform implementations call the existing synchronous logic and
resolve the result immediately. This allows callers to migrate to the async API
before the Linux implementation is moved off the main thread.

Comment 3

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Use isDefaultBrowserAsync() in ShowHeartbeatAction; r=#nimbus-reviewers

Use the asynchronous default-browser check when generating the Heartbeat
post-answer URL.

Comment 4

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Use isDefaultBrowserAsync() in TelemetryEnvironment; r=#toolkit-telemetry-reviewers-rotation

Use the asynchronous default-browser check when collecting the Telemetry
environment settings.

Propagate the asynchronous operation through the settings update path.

Comment 5

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Use isDefaultBrowserAsync() in ClientEnvironmentBase; r=mossop,#toolkit-telemetry-reviewers-rotation

Use the asynchronous default-browser check when retrieving the default-browser
state in ClientEnvironmentBase.

Propagate the asynchronous operation to UsageReporting and its test.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/8571526f39a9
https://hg.mozilla.org/integration/autoland/rev/307385619a78
Clean up nsGNOMEShellService::IsDefaultBrowser(); r=gtk-reviewers,emilio

Comment 7

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/307385619a78

Comment 8

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Rename nsToolkitShellService to nsShellService and streamline the shared base class; r=#firefox-desktop-core-reviewers,#gtk-reviewers

Make nsToolkitShellService provide the shared nsISupports implementation,
including reference counting and QueryInterface for nsIToolkitShellService.

Update the platform shell services to fully inherit that implementation and
document the IsDefaultBrowser() virtual hook in preparation for adding a shared
nsIShellService::isDefaultBrowserAsync() implementation.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/d62eed02d8e0
https://hg.mozilla.org/integration/autoland/rev/736b684d3fd9
Rename nsToolkitShellService to nsShellService and streamline the shared base class; r=gtk-reviewers,emilio
https://github.com/mozilla-firefox/firefox/commit/caf56d40d2a4
https://hg.mozilla.org/integration/autoland/rev/d0df11fe3948
Add isDefaultBrowserAsync() to nsIShellService; r=gtk-reviewers,emilio

Comment 10

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/736b684d3fd9
https://hg.mozilla.org/mozilla-central/rev/d0df11fe3948

Comment 11

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/736b684d3fd9
https://hg.mozilla.org/mozilla-central/rev/d0df11fe3948

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/0144c4c197f9
https://hg.mozilla.org/integration/autoland/rev/499d7aad36fa
Use isDefaultBrowserAsync() in ShowHeartbeatAction; r=nimbus-reviewers,beth

Comment 13

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/499d7aad36fa

Comment 14

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Ignore early default-browser updates in TelemetryEnvironment; r=#toolkit-telemetry-reviewers-rotation

Return early from _updateDefaultBrowser() before session restore, following
the pattern used by _updateSearchEngine(). Log ignored calls instead of
assigning null to isDefaultBrowser.

Comment 15

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Record browser.default_at_launch after the delayed default-browser check; r=#toolkit-telemetry-reviewers-rotation

The metric is recorded before session restore, when the default-browser value
is not yet available, and is not updated when the delayed check completes.

Move the Glean write into _updateDefaultBrowser() so it records the check’s
result after session restore. Add a test assertion that the metric contains a
boolean.

Comment 16

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Await the default-browser update in TelemetryEnvironment tests; r=#toolkit-telemetry-reviewers-rotation

The delayed default-browser test waits for search service initialization but
not for the default-browser check. It currently passes with the trivial async
implementation, but could become flaky when the check runs on a background
thread and takes longer.

Add a small async work tracker so the test can await both operations before
checking the telemetry environment. The helper can also support other async
work started by EnvironmentCache observers.

Comment 17

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/2f6dea86ff7b
https://hg.mozilla.org/integration/autoland/rev/9a9ba6e7119f
Ignore early default-browser updates in TelemetryEnvironment; r=TravisLong
https://github.com/mozilla-firefox/firefox/commit/687d92e91cf5
https://hg.mozilla.org/integration/autoland/rev/95365cb6f4cc
Record browser.default_at_launch after the delayed default-browser check; r=TravisLong

Comment 18

[pstanciu]

https://hg.mozilla.org/mozilla-central/rev/9a9ba6e7119f
https://hg.mozilla.org/mozilla-central/rev/95365cb6f4cc

Comment 19

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/d105184fe0e7
https://hg.mozilla.org/integration/autoland/rev/8e04a2772c13
Use isDefaultBrowserAsync() in TelemetryEnvironment; r=chutten

Comment 20

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Use isDefaultBrowserAsync() in BrowserGlue; r=#firefox-desktop-core-reviewers

Use the asynchronous default-browser check when recording the result of the
set-to-default Spotlight.

Comment 21

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Use isDefaultBrowserAsync() in DefaultBrowserCheck; r=#firefox-desktop-core-reviewers

Use the asynchronous default-browser check when determining whether the
default-browser prompt should be shown.

Comment 22

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Use isDefaultBrowserAsync() in AboutWelcomeParent; r=#omc-reviewers

Use the asynchronous default-browser check when determining whether About
Welcome needs to set Firefox as the default browser.

Update the related About Welcome targeting tests to stub the asynchronous API.

Comment 23

[agoloman]

https://hg.mozilla.org/mozilla-central/rev/8e04a2772c13

Comment 24

[Jan Varga [:janv]]

Attachment: Bug 2074009 - Use isDefaultBrowserAsync() in ASRouterTargeting; r=#omc-reviewers

Use the asynchronous default-browser check for the cached and uncached ASRouter
targeting attributes. Together with the preceding migrations, this removes
default-browser checks as a source of UI stalls during startup.

Update the related ASRouter tests to use and stub the asynchronous API.