Subj : Help with rooting, JSStrings and JS_DefineFunction
To   : netscape.public.mozilla.jseng
From : altan
Date : Wed Dec 01 2004 10:49 am

I have a question regarding interfacing C functions with JavaScript
(SpinderMonkey RC3) and the proper use of rooting.  I've searched high
and low for an answer, but have come up with nothing on this specific
subject.

When interfacing a C function with JavaScript, JS_DefineFunction is
used.  Let's assume the following C function is eventually called

constructInternal(
	JSContext *cx, 
	JSObject **obj, 
	uintN argc, 
	jsval *argv, 
	jsval *rval)
{
	...
}

If one (or more) of the parameters passed in the argv is a JSString
and the C code will continue to reference this JSString after
constructInternal returns, do I need to worry about this string being
garbage collected?  For example, might it be garbage collected if the
script containing the string that caused constructInternal to be
executed terminates or under any other conditions?

In general, what are the rules for keeping pointers to arbitrary
argv's after a C function returns?  Must I use JS_AddRoot in all such
cases?

Thanks in advance for any help.

.... Altan

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