Subj : Re: spidermonkey cross script execute doesn't work
To   : Mike Moening
From : Brendan Eich
Date : Wed Mar 16 2005 10:11 pm

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

.