Subj : Re: spidermonkey cross script execute doesn't work
To   : netscape.public.mozilla.jseng
From : Mike Moening
Date : Thu Mar 17 2005 09:47 am

Exactly what is a "Root" and do I have to name them unique or can I create a
single "root name" for all my objects that require rooting.

Thanks

"Brendan Eich" <brendan@meer.net> wrote in message
news:42391FA6.1030201@meer.net...
> Mike Moening wrote:
> > Thanks for your reply!
> >
> > To recap my understanding:
> >
> > Basically the JS_CompileScript generates the bytecode but nothing else.
> > (Allows for multiple execute calls)
>
>
> That's right -- no side effects, just the result returned.
>
>
> > The JSEvaluateScript actually "runs" the script.
>
>
> Including processing declarations per ECMA-262 section 10 (entering
> execution contexts).
>
>
> > So in the case of the 1st script I have to be a little carefull not to
add
> > any javascript code that would actually execute other than declaring
> > functions which would be called by the second script.
>
>
> Not sure why not -- you can interleave declarations and code among N
> scripts, if you don't make forward references from script i to script j,
> j > i.
>
>
> > One followup question.  Is it necessary to "Root" the compiled scripts
to
> > protect them from GC?
>
>
> Yes.
>
>
> > I'm not really clear on how this actually works.
>
>
> Call JS_NewScriptObject and store its return value in a rooted pointer.
>
>
> > I store my compiled JS_Script pointers an a <map> for later reference.
Are
> > they safe?
>
>
> No.  You need objects wrapping each, created by JS_NewScriptObject, and
> you need to root or otherwise protect those object references (you could
> implement a JSClass.mark hook that marks them, if the map is associated
> with an object [global object?] of a class you designed).
>
> /be

.