wait-free unbounded MPMC queue

[Dmitry Vyukov]

Hi,

Here is the queue:

https://github.com/pramalhe/ConcurrencyFreaks/blob/master/papers/crturnqueue-2016.pdf
http://concurrencyfreaks.blogspot.de/2016/10/crturn-queue-first-mpmc-memory.html
https://github.com/pramalhe/ConcurrencyFreaks/blob/master/CPP/papers/crturnqueue/include/CRTurnQueue.hpp

The main data structure seems to be exactly as M&S queue, and it is
updated using the same sequence of operations. The novel part is
helping mechanism that ensures that each operation completes in at
most maxThreads steps.