kjcamann added a comment.
I have recently benchmarked this (platform was RHEL 7 and Haswell), and the
libc++ version has about twice the latency of a pthread_rwlock for both classes
of locking. libc++ is also about twice the latency of the libstdc++
implementation, because it is just a lightwei
theraven added a comment.
I missed this when it went in and coming across the code now I'm quite
surprised that it did. Why is `shared_mutex` not implemented as a wrapper
around rwlocks (pthreads and Windows both provide this abstraction)? The
current implementation looks a lot less efficient
