670551 - nsIdleService occasionally has spurious "back"/"idle" notifications in the middle a long idle periods

Status: NEW

(Core :: Widget, defect)

Description

[James Ross]

Attachment: Custom log of idle service and notifications

I noticed this problem when I upgraded my XULRunner for ChatZilla to Gecko 2.0 and while idle overnight, every 10 minutes or so, it would mark me "back" and then immediately "away" again. The ChatZilla away/back is directly tied to the nsIIdleService so I logged that and saw the data (idleTime -> timeStr in the code) was just fine - i.e. it has a large idle time even for the "back" notifications!

So I've compiled trunk (18c8c2ea4caf07635792b70168fad1d8a6694a38) and attached is a log from nsIdleService.cpp, just after timeStr.AppendInt(idleTime), using the following code:

printf("nsIdleService::CheckAwayState: mLHA=%d -> %d, cTime=%d, lTime=%d, iTime=%d (%d)\n", mLastHandledActivity, curTime - idleTime, curTime, lastTime, idleTime, idleTimeMS);

I have intermixed it with the notifcations ChatZilla received during the same period to highlight when it goes wrong.

As far as I can tell, this problem exists as a result of bug 544240 switching all the important calculations to use seconds instead of milliseconds. It now has rounding issues. :)

Comment 1

[James Ross]

In case there's any confusion, I added idleTimeMS myself a little earlier to see how badly it was rounding, like this:

  PRUint32 idleTimeMS = idleTime;
  idleTime /= 1000;

Comment 2

[:Irving Reid (No longer working on Firefox)]

This may have been resolved by bug 811459.