621378 - Web Workers: Blocking tab-switching and access to main menu, all events are delivered after tab is closed

Status: REOPENED

(Firefox :: General, defect)

Description

[Stefan]

User-Agent:       
Build Identifier: Mozilla/5.0 (X11; Linux x86_64; rv:2.0b9pre) Gecko/20100101 Firefox/4.0b9pre

The example code in "Web Workers Draft Recommendation — 7 December 2010" blocks tab switching and access to the main menu. FF does not offer the user to stop the script. The script can only be stopped by closing the tab. After the tab has vanished the collected events (mouse clicks) are delivered to the FF.

http://www.whatwg.org/specs/web-workers/current-work/

Reproducible: Always

Steps to Reproduce:
1. open http://www.whatwg.org/demos/workers/primes/page.html
2.
3.
Actual Results:  
- Tab switching is disabled.
- Menu access is disabled.
- All events are delivered at once after tab is closed.

Expected Results:  
- Allow tab switching.
- Allow Menu access.
- Don't collect events for later delivery.

Comment 1

[aravindm]

Mozilla/5.0 (Windows NT 6.1; rv:2.0b9pre) Gecko/20101226 Firefox/4.0b9pre

Able to reproduce.

Comment 2

[Tyler Downer [He/Him]]

This bug was reported using a pre-release version of Firefox 4. Now that Firefox 4.0.1 final has been released, can you please update and retest your bug? A fresh profile would be a good starting place to test, 
http://support.mozilla.com/kb/Managing+profiles. If you continue to see the issue, can you please update this bug with your results?

Filter: firefox4prebugsunco

Comment 3

[Stefan]

Browser is still locked while web worker is working. Checked with
Mozilla/5.0 (X11; Linux x86_64; rv:7.0a1) Gecko/20110603 Firefox/7.0a1

Comment 4

[Ben Turner (not reading bugmail, use the needinfo flag!)]

This is fixed with bug 649537.

Comment 5

[Stefan]

(In reply to comment #4)
> This is fixed with bug 649537.

I get five rejects if I try to apply the patch.

Comment 6

[Ben Turner (not reading bugmail, use the needinfo flag!)]

It's based on the tracemonkey repo, not mozilla-central. It'll get merged sometime soon hopefully.

Comment 7

[Stefan]

According to Bug 649537 the purported fix of Comment #4 should have landed:
http://hg.mozilla.org/mozilla-central/rev/f631e1b0e296
Nonetheless it ain't work for me. I'm using a brand new build based on revision f92e021f1f44.

Comment 8

[Ben Turner (not reading bugmail, use the needinfo flag!)]

Really? I just tested with today's nightly and everything works just fine...

Comment 9

[Stefan]

Very strange. I 'll have to bisect my profile.

Comment 10

[Stefan]

A preliminary result when starting from a fresh profile + nightly 
Mozilla/5.0 (X11; Linux x86_64; rv:8.0a1) Gecko/20110731 Firefox/8.0a1:

1. Open http://www.whatwg.org/demos/workers/primes/page.html in first tab.
2. Open further tabs, e.g. (stern.de, spiegel.de and focus.de in tab two, three and four).
3. Wait with tab four in the foreground for the "unresponsive script" message.
4. click "Continue"

Actual Result: Program menues are no longer accessible.

There is a variation:

1: Browser changes to tab 1 but does not immediately display "unresponsive script" message. Switching tabs impossible, menu inaccessible.
2: After clicking "Continue" in the dialog one cannot switch tabs.

Comment 11

[Stefan]

Even simpler: Start with no profile (rm -fr .mozilla) and on the command line start

firefox http://www.whatwg.org/demos/workers/primes/page.html

Wait until it's "counting". Then play around with the menus. Try to open them. Repeat if it works until it no longer does.

Open new tab ("+"-Button): Events previously generated in the menus are now delivered to the program.