Open Bug 1327925 Opened 8 years ago Updated 2 years ago

[e10s] Too huge delay between focus and blur when I press Alt+Enter in urlbar (Sound briefly appears on http://coub.com)

Categories

(Core :: DOM: UI Events & Focus Handling, defect, P3)

Product:
Core
Component:
DOM: UI Events & Focus Handling
Type:
defect

Tracking

()

People

(Reporter: arni2033, Unassigned)

References

(
URL
)

Details

(Keywords: perf) 

>>>   My Info:   Win7_64, Nightly 49, 32bit, ID 20160526082509
STR_1:
1. Open https://coub.com/view/43oxwxwj (that music is easy to detect), make sure there's a sound
2. Click in urlbar
3. Type "example.org", press Alt+Enter

AR:  Sound briefly appears
ER:  No sound

Explanation why I filed this in "Core - Event handling":
Coub plays music on 'focus' event. When I press Alt+Enter in urlbar, Firefox briefly focuses the page
and then focuses newly opened page sending 'blur' event to old one.
However, there's a delay. I obtained the following results using STR_2:
>      non-e10s: ~40ms      e10s: ~300ms      GoogleChrome: ~1ms
I think that the old page shouldn't be focused at_all, as if I pressed Ctrl+T instead of Alt+Enter

STR_2:
1. Open the following "data:" url or click URL in the form above
> data:text/html,<body onfocus = "window.i=window.i||1;console.log(Date.now()+'_focus_'+i++)" onblur = "window.i=window.i||1;console.log(Date.now()+'_blur_'+i++)">
2. Open console in separate window, clear it. Click on the page. Click in urlbar. Wait ~5 seconds
3. Type "example.org", press Alt+Enter.
4. Switch to console, check timestamps of the "focus" and "blur" events (last 2 events)
No longer blocks: 1277113
Component: Untriaged → Event Handling
Product: Firefox → Core
I'm not experiencing a significant delay with STR_1. Chrome is definitely snappier tho - and it pop/clicks much less.
Keywords: perf
Priority: -- → P3
Component: Event Handling → User events and focus handling
Severity: normal → S3
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