Comments on: Matt Kruse nails it w/r/t IE and closures http://billhiggins.us/blog/2007/01/05/matt-kruse-nails-it-wrt-ie-and-closures/ Mon, 16 Jan 2012 02:27:45 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Brendan Eich http://billhiggins.us/blog/2007/01/05/matt-kruse-nails-it-wrt-ie-and-closures/comment-page-1/#comment-12 Brendan Eich Sat, 20 Jan 2007 00:08:45 +0000 http://billhiggins.us/weblog/2007/01/05/matt-kruse-nails-it-wrt-ie-and-closures/#comment-12 BTW, I am sure that MS could implement something like the Bacon and Rajan algorithm (modulo patent licensing, if IBM were to require one ;-)). Why don't they? Browser implementors are supposed to work harder, so that web developers don't have to stand on their heads with workarounds or be told not to use fundamental language features. Anyway that is our philosophy at Mozilla. /be BTW, I am sure that MS could implement something like the Bacon and Rajan algorithm (modulo patent licensing, if IBM were to require one ;-) ). Why don’t they? Browser implementors are supposed to work harder, so that web developers don’t have to stand on their heads with workarounds or be told not to use fundamental language features. Anyway that is our philosophy at Mozilla.

/be

]]> By: Brendan Eich http://billhiggins.us/blog/2007/01/05/matt-kruse-nails-it-wrt-ie-and-closures/comment-page-1/#comment-11 Brendan Eich Sat, 20 Jan 2007 00:02:30 +0000 http://billhiggins.us/weblog/2007/01/05/matt-kruse-nails-it-wrt-ie-and-closures/#comment-11 The DOM in IE is implemented via "scriptable COM objects", for some value of those words. COM uses reference-counting without cycle collection, JS must hold strong references to DOM objects, and the DOM window object must strongly reference JS objects, so the bug is inevitable given the design. Mozilla has had similar but less frequently encountered leaks due to cycles in our JS object and XPCOM reference-counted object graph. These have been fixed over the years in specific and more generic ways. The latest fix in the open source "trunk" uses a single cycle collector based on http://citeseer.ist.psu.edu/532569.html and it thereby eliminates a lot of more specific cycle-breaking and -collecting code. In fixing the bugs we've faced due to lack (until now) of generic cycle collection capability in XPCOM, we have never claimed that closures are the problem and the fix is not to use them. That's just so wrong on so many levels, I'm surprised that MS tried it out. Thanks for holding their feet to the fire. /be The DOM in IE is implemented via “scriptable COM objects”, for some value of those words. COM uses reference-counting without cycle collection, JS must hold strong references to DOM objects, and the DOM window object must strongly reference JS objects, so the bug is inevitable given the design.

Mozilla has had similar but less frequently encountered leaks due to cycles in our JS object and XPCOM reference-counted object graph. These have been fixed over the years in specific and more generic ways. The latest fix in the open source “trunk” uses a single cycle collector based on http://citeseer.ist.psu.edu/532569.html and it thereby eliminates a lot of more specific cycle-breaking and -collecting code.

In fixing the bugs we’ve faced due to lack (until now) of generic cycle collection capability in XPCOM, we have never claimed that closures are the problem and the fix is not to use them. That’s just so wrong on so many levels, I’m surprised that MS tried it out. Thanks for holding their feet to the fire.

/be

]]> By: Bill Higgins http://billhiggins.us/blog/2007/01/05/matt-kruse-nails-it-wrt-ie-and-closures/comment-page-1/#comment-10 Bill Higgins Sat, 06 Jan 2007 13:22:42 +0000 http://billhiggins.us/weblog/2007/01/05/matt-kruse-nails-it-wrt-ie-and-closures/#comment-10 No Andrew, IE leaks memory routinely, just in the course of writing normal Javascript/DOM code. See the folllowing: http://www.crockford.com/javascript/memory/leak.html http://msdn.microsoft.com/library/default.asp?url=/library/en-us/IETechCol/dnwebgen/ie_leak_patterns.asp http://alex.dojotoolkit.org/?p=526 PS - I'm not even sure what a "scriptable COM object" is. I know the pre-IE7 XmlHttpRequest object was an ActiveX object in IE, and there's some relationship between COM and ActiveX - could you provide some other examples? No Andrew, IE leaks memory routinely, just in the course of writing normal Javascript/DOM code.
See the folllowing:

http://www.crockford.com/javascript/memory/leak.html

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/IETechCol/dnwebgen/ie_leak_patterns.asp

http://alex.dojotoolkit.org/?p=526

PS – I’m not even sure what a “scriptable COM object” is. I know the pre-IE7 XmlHttpRequest object was an ActiveX object in IE, and there’s some relationship between COM and ActiveX – could you provide some other examples?

]]> By: Andrew http://billhiggins.us/blog/2007/01/05/matt-kruse-nails-it-wrt-ie-and-closures/comment-page-1/#comment-9 Andrew Sat, 06 Jan 2007 11:03:06 +0000 http://billhiggins.us/weblog/2007/01/05/matt-kruse-nails-it-wrt-ie-and-closures/#comment-9 MS is not about to 'fix the problem' because it is not really a problem. The 'bug' as I understand it only occurs when using scriptable COM objects within Javascript, and is more than likely un-fixable. The work-around (if you can call it that) is not to use scriptable COM objects within your javascript. Hardly a showstopper. MS is not about to ‘fix the problem’ because it is not really a problem.

The ‘bug’ as I understand it only occurs when using scriptable COM objects within Javascript, and is more than likely un-fixable. The work-around (if you can call it that) is not to use scriptable COM objects within your javascript.

Hardly a showstopper.

]]> By: Josh Staiger http://billhiggins.us/blog/2007/01/05/matt-kruse-nails-it-wrt-ie-and-closures/comment-page-1/#comment-8 Josh Staiger Fri, 05 Jan 2007 17:00:10 +0000 http://billhiggins.us/weblog/2007/01/05/matt-kruse-nails-it-wrt-ie-and-closures/#comment-8 Right on the money! Right on the money!

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