My question does not directly pertains to ck, but in principle it is relevant to its subject and potentially one day might result into a contribution to it.
I posted on stackoverflow quite a lengthy writeup with my thoughts on a venerable RW ticket lock algorithm by John M. Mellor-Crummey and Michael L. Scott. I found what I think is an enhancement over it. Also I provided a C++ implementation for that (not well tested yet though).
I will greatly appreciate any feedback on this lock variant.