[deweerdt]

Yes, that's my understanding of the implementation as well. I was commenting on the fact that you might have two totally unrelated p1 and p2, where (hash(p1) % SIZE_OF_POOL) == (hash(p2) % SIZE_OF_POOL), that will end up sharing the same mutex.

[jguegant]

Yes definitely tricky. It might give a heart attack to some high frequency system designers! I will investigate this topic in future: maybe someone can come up with a spin-lock or lock free solution.