From:  Nick Fitzgerald <nfitzgerald@mozilla.com>
Date:  17 Aug 2016 03:50:26 Hong Kong Time
Newsgroup:  news.mozilla.org/mozilla.dev.tech.js-engine.internals
Subject:  

Re: Heads up: Don't use NSPR threading anymore, use js/src/threading/* instead!

NNTP-Posting-Host:  63.245.214.181

On Tue, Aug 16, 2016 at 10:01 AM, Ehsan Akhgari 
wrote:

> On 2016-08-15 2:15 PM, Nick Fitzgerald wrote:
> > You may have seen some bug mail for
> > https://bugzilla.mozilla.org/show_bug.cgi?id=956899 and its dependent
> bugs.
> > Well, the migration off of NSPR threading is almost complete! Please
> don't
> > introduce any more uses of NSPR threading or jslock.h, and if you're
> > reviewing a patch, don't r+ any new uses.
> >
> > This work is giving us saner APIs (mostly modeled after the C++14
> > concurrency primitives, also some based on Rust's std lib), better DEBUG
> > assertions, and makes life a tiny bit easier for our embedders.
>
> Is SpiderMonkey going to stop depending on NSPR completely when this
> work finishes?  I'm asking because there are some NSPR dependencies that
> bug 1275749 (the only open dependency of bug 956899) doesn't capture...
>

​No, it will not.

My understanding is that using NSPR's threading is​ one of the biggest
roadblocks for building SpiderMonkey as a static lib again, but you'd have
to ask glandium for more details in
https://bugzilla.mozilla.org/show_bug.cgi?id=1176787