1219150 - Detect whether we are currently blocking a user-initiated interaction

Status: RESOLVED FIXED

(Toolkit :: Performance Monitoring, defect)

Description

[David Teller [:Yoric] - still alive but not very active]

This, with bug 1219145, would let us decrease further false positives.

Comment 1

[David Teller [:Yoric] - still alive but not very active]

Boris, I know that we can detect whether an event is user-initiated. Can you point me towards the code that does that?

Comment 2

[Boris Zbarsky [:bzbarsky]]

EventStateManager::IsHandlingUserInput(), perhaps?

And a scriptable API at http://mxr.mozilla.org/mozilla-central/source/dom/interfaces/base/nsIDOMWindowUtils.idl#1670

Comment 3

[David Teller [:Yoric] - still alive but not very active]

`EventStateManager::IsHandlingUserInput()` looks like a good candidate, indeed. It does cause a call the the clock, so we don't want to call it too often, though.

If we are willing to accept a few more false positives, `static int32_t EventStateManager::sUserInputEventDepth` could provide a good approximation, except in case of nested event loops.

Comment 4

[David Teller [:Yoric] - still alive but not very active]

Attachment: MozReview Request: Bug 1219150 - EventStateManager::{LatestUserInputStart, UserInputCount};r=smaug

Bug 1219150 - EventStateManager::{LatestUserInputStart, UserInputCount};r?smaug

To detect slow behaviors, it is useful to find out whether a user
input was handled between two instants.

This patch introduces EventStateManager::UserInputCount, which lets
client code determine whether user input was handled between two
points of execution, and EventStateManager::LatestUserInputStart,
which lets client code find out when the altest user input was
handled.

Comment 5

[Olli Pettay [:smaug][[e-mail]]]

Comment on attachment 8694720 [details]
MozReview Request: Bug 1219150 - EventStateManager::{LatestUserInputStart, UserInputCount};r=smaug

Now I'm lost... didn't I review this for Bug 1186491

Comment 6

[David Teller [:Yoric] - still alive but not very active]

Sorry, I must have made a mistake with MozReview. This is the right bug.

Comment 7

[David Teller [:Yoric] - still alive but not very active]

Comment on attachment 8694720 [details]
MozReview Request: Bug 1219150 - EventStateManager::{LatestUserInputStart, UserInputCount};r=smaug

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/26841/diff/1-2/

Comment 8

[David Teller [:Yoric] - still alive but not very active]

Comment on attachment 8694720 [details]
MozReview Request: Bug 1219150 - EventStateManager::{LatestUserInputStart, UserInputCount};r=smaug

https://reviewboard.mozilla.org/r/26841/#review24427

Accidentally reviewed as part of bug 1186491.

Comment 9

[Pulsebot]

https://hg.mozilla.org/integration/fx-team/rev/badf9e19d881

Comment 10

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/badf9e19d881