1941792 - Stop using weak ref in DownloadsCommon.sys.mjs

Status: RESOLVED FIXED

(Firefox :: Downloads Panel, task)

Description

[Tooru Fujisawa [:arai]]

The PrefObserver uses aHoldWeak parameter of the addObserver, but the PrefObserver lives longer than the observer list, given
the list is cleared at xpcom-shutdown, but the system modules are unloaded after that.

Thus, using strong reference there doesn't leak the observer, and using strong reference is necessary after bug 1941472 to explicitly keep the observer alive.

https://searchfox.org/mozilla-central/rev/86c208f86f35d53dc824f18f8e540fe5b0663870/browser/components/downloads/DownloadsCommon.sys.mjs#93-97,113,115

var PrefObserver = {
  QueryInterface: ChromeUtils.generateQI([
    "nsIObserver",
    "nsISupportsWeakReference",
  ]),
...
  register(prefs) {
...
    kPrefBranch.addObserver("", this, true);

Comment 1

[Tooru Fujisawa [:arai]]

Attachment: Bug 1941792 - Stop using weak ref in DownloadsCommon.sys.mjs. r?Gijs!

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8d8e22d0e7be
Stop using weak ref in DownloadsCommon.sys.mjs. r=Gijs

Comment 3

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/8d8e22d0e7be