412418 - Synchronous XMLHttpRequest interferes with setTimeout

Status: RESOLVED DUPLICATE of bug 340345

(Core :: DOM: Core & HTML, defect)

Description

[Mark Wubben]

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en; rv:1.8.1.12pre) Gecko/20080105 Camino/1.6b1pre (like Firefox/2.0.0.12pre)
Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9b3pre) Gecko/2008011404 Minefield/3.0b3pre

I'm running a lot of timeouts with delay of 0ms. The timeout method performs a synchronous XHR. More than half of the time, the next timeout is fired when the XHR loads, instead of continuing the execution of the first timeout method.

I've verified the issue on Mac OS X 10.5.1 and on Ubuntu Linux, with the Firefox nightly build from January 14th, 2008.

Reproducible: Always

Steps to Reproduce:
1. Schedule two timeouts at 0ms delay
2. Make sure the first timeout performs a synchronous XHR

Actual Results:  
Observe that the second timeout is fired before the first timeout has finished execution.

Expected Results:  
The first timeout finishes execution, and only then the second timeout is fired.

Comment 1

[Mark Wubben]

Attachment: Test case to reproduce the issue.

Comment 2

[Bob Clary [:bc] (inactive)]

> DOM:Mozilla Extensions, dupe of bug 340345 ?

Comment 3

[BAM]

Attachment: Simple example of this issue

Simple example, should alert 1,2,3,4, works in Firefox 2 and IE 6 and 7, in Firefox 3 alerts 1,4,2,3

Comment 4

[BAM]

Yeah, dupe of DOM:Mozilla Extensions, dupe of bug 340345