> On Dec 14, 2015, at 7:39 PM, Kevin Ballard <ke...@sb.org> wrote: > >> On Mon, Dec 14, 2015, at 07:34 PM, Greg Parker wrote: >> >>> On Dec 14, 2015, at 7:26 PM, Kevin Ballard via swift-dev >>> <swift-dev@swift.org> wrote: >>> >>>> On Mon, Dec 14, 2015, at 12:19 PM, Greg Parker via swift-dev wrote: >>>> >>>>> On Dec 14, 2015, at 9:47 AM, John McCall via swift-dev >>>>> <swift-dev@swift.org> wrote: >>>>> >>>>>> On Dec 12, 2015, at 7:04 PM, Chris Lattner <clatt...@apple.com> wrote: >>>>>> #3 sounds like a great approach to me. I agree with Kevin that if we >>>>>> keep the object husk approach that any use of a weak pointer that >>>>>> returns nil should drop any reference to a husk. >>>>> >>>>> Spin locks are, unfortunately, illegal on iOS, which does not guarantee >>>>> progress in the face of priority inversion. >>>> >>>> There is a spinlock algorithm that does work (in practice if not in >>>> theory), but it requires a full word of storage instead of a single bit. >>> >>> Is that what OSSpinLock uses? >> >> It does not. OSSpinLock is unsafe unless you can guarantee that all users >> have the same priority. > > Hmm, that's pretty unfortunate to hear. I've written code with spinlocks on > iOS, and I imagine I'm not the only one. Does the system provide an > implementation of this "safe in practice" spinlock that's visible to > third-party devs?
Not that I know of. You should file a bug report. -- Greg Parker gpar...@apple.com Runtime Wrangler _______________________________________________ swift-dev mailing list swift-dev@swift.org https://lists.swift.org/mailman/listinfo/swift-dev
