Bug 16561 – remove debugger overhead from non-debugged JavaScript execution

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Darin Adler]

I got a 1.5% speed-up by putting the debugger code into separate nodes, only created if needed.

[Darin Adler]

Created attachment 18037 [details]
patch

[Darin Adler]

Created attachment 18038 [details]
improved patch; 1.022x as fast SunSpider

[Oliver Hunt]

Is it possible to break out the sourceelements change into a seperate patch? it makes the current patch somewhat noisy.

[Eric Seidel (no email)]

Comment on attachment 18038 [details]
improved patch; 1.022x as fast SunSpider

Looks great.

Two things:
1.  SourceElements::release( needs a better name:
children->release(m_children);
that code makes little sense at first pass.

2nd.  This now changes the behavior of Drosera so that you need to attach *before* you load a page.  We need to file at least one (possibly two) followup bugs to this one.
1.  Add the ability walk the tree and swap in/out break nodes for when the first/last debugger attaches/detaches.
2.  If #1 doesn't get done soon, we'll need to teach Drosera how to recognize that it's trying to debug a JavaScript page which hasn't been parsed with debugging information and display a note to the user to reload the scripts (or just have it reload the scripts automatically)

[Darin Adler]

(In reply to comment #4)
> This now changes the behavior of Drosera so that you need to attach
> *before* you load a page.

We just checked with Tim Hatcher, and it turns out that was already true about Drosera.

r28937