Subj : rooting objects across threads
To   : netscape.public.mozilla.jseng
From : zakalawe@mac.com (James Turner)
Date : Sun Aug 03 2003 05:56 am

I've recently begun the process of add threading to my JS embedding
application, and need a few things clarified. I'll break things into a
few seperate posts to keep the subjects clearer.

Firstly, what is the relationship between contexts and rooting objects
to avoid garbage collection? Essentially, I am doing this:

Thread 1: (main thread)

jsval myVal = ..... convert some data into JS ...
// should JS_AddRoot myVal here?
thread_safe_queue.add(myVal);


Thread 2: (worker thread)

while ( 1 ) {
    // next line will block if the queue is empty
    jsval workData = thread_safe_queue.next();

   JS_BeginRequest();

    ... do some long, blocky work with the workData ....

  JS_EndRequest()

  JS_MaybeGC();
}

So, my obvious worry is, what do need to do to stop items waiting in
my work queue being garbage collected before they're processed? It
looks froms the docs as if JS_AddRoot is context specific, but
obviously my main thread and worker threads each have their own
context.

I saw a reference to JS_LockGCThingRT, which only takes a JSRuntime*
instead of a context, perhaps this is what I should be using? Any
suggestions appreciated.

(And as an aside, is my use of [begin|end]Request, and maybeGC roughly
correct?)


Many thanks,
James

.