1383244 - Idle timeout doesn't always happen as expected with the `idle` api

Status: NEW

(WebExtensions :: General, defect, P5)

Description

[Paul Morris [:pmorris]]

The idle timeout with the idle api[0] doesn't always work as expected.

I'm working on porting "Mind the Time"[1] to WebExtensions and have uploaded some beta releases.  Sometimes I'll leave my laptop sitting for awhile with a tab/window activated/focused.  Usually the idle timeout will happen and the right amount of time will be logged for the current domain, but sometimes the idle timeout does not happen and way too much time is logged.

This is on FF 55.0 dev edition, multi-process, on Ubuntu 16.04, with my own profile with many open tabs, other add-ons, and several windows open.  I've added console logging to the beta version of Mind the Time to explore the issue and it shows that the idle timeout does not always fire when I expect it to.

This leads to a regression in my addon's functionality that's blocking its migration to WebExtensions.

[0] https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/idle
[1] https://addons.mozilla.org/en-US/firefox/addon/mind-the-time/

Comment 1

[Andy McKay]

This sounds similar to bug 1359403, although that talks about alarms and suspension but not sure if its a duplicate. See also bug 1377744.

Comment 2

[Paul Morris [:pmorris]]

I don't think this is a duplicate of either of those other bugs.  This one involves the `idle` api and AFAICT the others don't.  This bug is tricky because mostly the idle timeout works, but when it doesn't it makes the time logged by my add-on incorrect, sometimes making it off by many hours.  And that messes up its primary functionality.

Comment 3

[Paul Morris [:pmorris]]

I made a simple add-on to help with detecting/reproducing the issue:
https://addons.mozilla.org/en-US/firefox/addon/idle-api-tester/

Comment 4

[Andrew Swan [:aswan]]

Paul, sorry for the slow reply but can you narrow this down a bit?  Did the non-webextension version of Mind the Time use nsIIdleService?  And are the quirks you're seeing unique to webextensions?  (ie, did you see similar things when using nsIIdleService directly?)

Comment 5

[Paul Morris [:pmorris]]

Sure thing.  Before webextensions Mind the Time was built with the add-on sdk, and used the sdk's lower level apis for idle timeout functionality.  Below is the code that uses "sdk/system/events" and "user-interaction-active".  I've only seen these quirks after converting to webextensions, not with the previous sdk version of the add-on.

let systemEvents = require("sdk/system/events");

exports.addActivityListener = function(callback) {
    systemEvents.on("user-interaction-active", callback);
};

exports.removeActivityListener = function(callback) {
    systemEvents.off("user-interaction-active", callback);
};

Comment 6

[Firefox Bug Husbandry Bot]

Bulk move of bugs per https://bugzilla.mozilla.org/show_bug.cgi?id=1483958