1682987 - Potential false negative when concurrently accessing ServiceWorkerParentInterceptEnabled

Status: RESOLVED FIXED

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

Description

[(No longer employed by Mozilla) Aaron Klotz]

The current implementation of ServiceWorkerParentInterceptEnabled uses two atomics to load the dom.serviceWorkers.parent_intercept pref.

As-is, there is a slight chance that this function could return a false-negative, given that sInitialized is set to true before sEnabled is set.

In general, though, IMHO this kind of pattern is typically a smell that this code could just be replaced by a C++11 "magic static" that safely initializes the value.

Comment 1

[(No longer employed by Mozilla) Aaron Klotz]

Attachment: Bug 1682987: Unconditionally return true from ServiceWorkerParentInterceptEnabled; r=#dom-workers-and-storage-reviewers

The current implementation
of ServiceWorkerParentInterceptEnabled uses two atomics to load the
dom.serviceWorkers.parent_intercept pref.

As-is, there is a slight chance that this function could return a false-negative,
given that sInitialized is set to true before sEnabled is set.

We replace the implementation with a "magic static" that ensures both that the
value will be loaded atomically and will not require locking for subsequent
accesses.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0a9bd8c4b59b
Unconditionally return true from ServiceWorkerParentInterceptEnabled; r=dom-workers-and-storage-reviewers,asuth

Comment 3

[Razvan Maries]

https://hg.mozilla.org/mozilla-central/rev/0a9bd8c4b59b