> On Dec 14, 2015, at 3:19 PM, Greg Parker via swift-dev <swift-dev@swift.org> > 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.
Do you have a pointer (unintentional pun, oops) to this algorithm? In this case, if we're going to dedicate a whole word to it, then we might as well go with the activity count implementation, but I'd be curious to read more just the same. Mike _______________________________________________ swift-dev mailing list swift-dev@swift.org https://lists.swift.org/mailman/listinfo/swift-dev
