343401 - GUI should run in a separate thread for each tab

Status: RESOLVED DUPLICATE of bug 40848

(Firefox :: Tabbed Browser, enhancement)

Description

[gidyn]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.4) Gecko/20060508 Firefox/1.5.0.4
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.4) Gecko/20060508 Firefox/1.5.0.4

Currently, all GUI activity takes place in the same thread. This means that, for example, if a page loading in the background is taking a long time to layout or has a long-running script, the entire browser freezes. This is particularly relevant for extensions which cause every large page to display slowly.

Reproducible: Always

Steps to Reproduce:
1. Use greasemonkey to inject a slow script into every page (yes, I have a very good reason for doing this)
2. Load some pages in background tabs
3. Make and drink a cup of coffee while waiting for the browser to become responsive


Expected Results:  
Each tab should layout its page and execute scripts in its own thread