Clamp setTimeout/setInterval to something higher than 10ms in inactive tabs

RESOLVED FIXED in mozilla5

Status

()

Core
DOM
P1
normal
RESOLVED FIXED
7 years ago
3 years ago

People

(Reporter: bz, Assigned: bz)

Tracking

(Depends on: 2 bugs, {dev-doc-complete})

Trunk
mozilla5
dev-doc-complete
Points:
---
Dependency tree / graph
Bug Flags:
in-testsuite ?

Firefox Tracking Flags

(Not tracked)

Details

Attachments

(2 attachments)

We throttle the refresh driver; we should throttle DOM timers too.  The issue is web compat...

On the other hand, I hear tell that other browsers are considering doing this, so at least we're not alone.
Oh, for refresh driver we throttle to 1Hz, but once 2.0 ships I'll land a patch to throttle to an doubling-each-time interval.

I don't think we want the doubling behavior for DOM timers, though.
nsGlobalWindow has its own concept of "active" which seems to do with focus.  I don't think we want to use that here, fwiw.
Created attachment 511636 [details] [diff] [review]
Pretty easy to do if we want to!
Attachment #511636 - Flags: review?(jst)
Assignee: nobody → bzbarsky
OS: Mac OS X → All
Priority: -- → P1
Hardware: x86 → All
Whiteboard: [need review]

Comment 4

7 years ago
Chrome is going to set the minimum interval to 0.5Hz I believe.
Yeah, that's what the attached patch uses as the default pref value.
Or rather it does 0.5s, which is what I think you meant.  We should clearly make it 1Hz to avoid that problem....

Comment 7

6 years ago
Chromium issue is http://code.google.com/p/chromium/issues/detail?id=66078 and they seem to use 1s.

dev-doc-needed: https://developer.mozilla.org/en/DOM/window.setTimeout#Minimum_delay_and_timeout_nesting will need to mention this change if it lands.
Keywords: dev-doc-needed
Comment on attachment 511636 [details] [diff] [review]
Pretty easy to do if we want to!

Let's give this a shot! Patch looks good (and I'm fine with either 1 or 2Hz here, maybe go with 1 to match chrome?).
Attachment #511636 - Flags: review?(jst) → review+
Duplicate of this bug: 532904
Whiteboard: [need review] → [need landing]
Pushed http://hg.mozilla.org/mozilla-central/rev/e328ab1bcb03 except I forgot to fix the commit message... I used a 1000ms clamp, but the commit message still says 500ms.  The correct number is 1000.
Status: NEW → RESOLVED
Last Resolved: 6 years ago
Flags: in-testsuite?
Resolution: --- → FIXED
Whiteboard: [need landing]
Target Milestone: --- → mozilla2.2
is there anything here that mobile/e10s needs to do to get this benefit?
I don't think so.  You're already flagging docshells as inactive so images get discarded, right?

I can write up a testcase for you to test whether this patch is working if you want (pretty easy to do a manual test; hard to do an automated one).
yes, i think we do.  alon would know specifically.  happy to run a test case.
I tested to make sure, and this works perfectly on mobile. Great stuff!

On a related note, this might make bug 588975 (stop animating images in background tabs) easier to do, which is also about reducing activity in inactive tabs.
Blocks: 588975
Created attachment 522433 [details]
Testcase that can be used to test this
Depends on: 646972

Updated

6 years ago
Depends on: 647001

Comment 16

6 years ago
This works on background tabs, but not on active tabs on minimized windows. Is this the expected behavior?

For comparison, in Chrome, the active tab of a minimized window is considered inactive.
> Is this the expected behavior?

For now, yes.  Which tabs are active is under control of the user interface; it might be worth a bug on Firefox to mark the active tab in a minimized window as inactive.
I filed bug 648045 and bug 648046 on applying the throttling in more cases.
Documentation updated:

https://developer.mozilla.org/en/DOM/window.setTimeout#Inactive_tabs

Also updated Firefox 5 for developers.
Keywords: dev-doc-needed → dev-doc-complete

Updated

6 years ago
Depends on: 652472
Depends on: 665000
Depends on: 667236
No longer depends on: 667236
Depends on: 663020

Updated

6 years ago
Depends on: 669016

Comment 20

6 years ago
Is there a specific DOM event that gets fired when the clamping to 1000 milliseconds starts (We would need to register a listener for it first of course though for it to be exposed...)? This currently trashes the JS GameBoy Color emulator audio when it's running inside of an inactive tab, as everything is driven in it at 16 ms intervals by a sole setInterval.

So the question remains, is there a unique DOM event that would fire solely for this throttling, to warn the web app of the slowdown? Doing normal timestamp comparisons is not the best, due to slow browsers (mobile especially) and timestamp checking for automatic pausing could get hacky.
> Is there a specific DOM event that gets fired

At this point, yes: http://www.w3.org/TR/2011/WD-page-visibility-20110602/#sec-visibilitychange-event

Comment 22

6 years ago
Thanks

Updated

5 years ago
Depends on: 836674
Depends on: 876032
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