Well, XPConnect is designed for the main thread, and many of the things it does assume that everything takes place on the main thread.
An example, from the topic of my head: whenever objects cross between JavaScript and C++ through XPConnect, they need to be retained in hashtables to preserve unicity, etc. For performance reasons, these hashtables are not protected against concurrent access. Another example: JavaScript objects can point towards C++ objects and vice-versa. The garbage-collector (well, the cycle-collector) needs to walk the graph in specific ways to get rid of possible cycles that involve both C++ and JS. The worker's implementation of the cycle-collector is much simpler (and quite different) than the main thread's, since it doesn't need to handle XPConnect. Mixing both accidentally can lead to unpredictable results. Oh, and XPConnect pointers can simply not be dereferenced from worker threads. Attempting to do so will crash libxul by design to avoid accidents. etc. Cheers, David On 03/01/16 17:45, 罗勇刚(Yonggang Luo) wrote: > > > On Mon, Jan 4, 2016 at 12:35 AM, David Rajchenbach-Teller > <dtel...@mozilla.com <mailto:dtel...@mozilla.com>> wrote: > > Accessing XPCOM in a worker will most likely break the garbage-collector > in novel and interesting ways, so I don't suggest heading in that > direction. > > I'd like to hear more information about that, > For example, if I setting a finalize for each XPCOM instance > Object(javascript), when the Object's is GCed, then I release > the xpcom instance, is that would not break the garbage-collector? > Or we have other problems about garbage-collector, I am interested in that. > > > > Cheers, > David > > On 03/01/16 17:24, 罗勇刚(Yonggang Luo) wrote: > > So that we could be able to access xpcom in worker. > > And we could be able to implement thunderbird new msg protocol in > pure > > javascript > > > > On Sun, Jan 3, 2016 at 11:09 PM, Josh Matthews > <j...@joshmatthews.net <mailto:j...@joshmatthews.net>> > > wrote: > > > >> What is the motivation for this work? > > >> > >> _______________________________________________ > >> dev-platform mailing list > >> dev-platform@lists.mozilla.org > <mailto:dev-platform@lists.mozilla.org> > >> https://lists.mozilla.org/listinfo/dev-platform > >> > > > > > > > > > > > -- > 此致 > 礼 > 罗勇刚 > Yours > sincerely, > Yonggang Luo _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
