Closed Bug 1438953 Opened 2 years ago Closed 2 years ago

Timer Precision Tests need a more generous float fuzziness value

Categories

(Core :: DOM: Events, enhancement, P2)

enhancement

Tracking

()

RESOLVED FIXED
mozilla60
Tracking Status
firefox60 --- fixed

People

(Reporter: tjr, Assigned: tjr)

References

Details

Attachments

(1 file)

Currently in the resist fingerprinting/reduce timer precision tests we have an allowance of ~.0000001 (milliseconds) to account for JAVASCRIPT (not the C++ calculations) fuzziness in float calculations.

When we are working with milliseconds since the epoch, a double's precision is around .0002; so we need to up our epsilon, or face the possibility of intermittents.
Priority: -- → P2
Comment on attachment 8951713 [details]
Bug 1438953 Increase the epsilon on timer reduction tests

https://reviewboard.mozilla.org/r/220996/#review227238

This seems reasonable.  Only shame is that we can't (or haven't yet) pull this out into common code.

::: commit-message-f191f:9
(Diff revision 1)
> +numbers, where doubles can represent very precise decimals. They don't work for large numbers
> +where doubles cannot represent such small decimals.

This seems like an awkward way to express the idea that large doubles can't have precise fractional parts.  WDYT about rewording this?
Attachment #8951713 - Flags: review?(nfroyd) → review+
Pushed by aciure@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/5db4200c90a8
Increase the epsilon on timer reduction tests r=froydnj
Keywords: checkin-needed
Okay, fixed the false positive case!
Flags: needinfo?(tom)
Keywords: checkin-needed
Pushed by ryanvm@gmail.com:
https://hg.mozilla.org/integration/autoland/rev/5eeff2b96802
Increase the epsilon on timer reduction tests r=froydnj
Keywords: checkin-needed
https://hg.mozilla.org/mozilla-central/rev/5eeff2b96802
Status: NEW → RESOLVED
Closed: 2 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla60
You need to log in before you can comment on or make changes to this bug.