(I feel this question is more appropriate for our performance forum)
Its very hard to point out whether it is a bottleneck or not unless you give us a clue about where it is used.
A simple i++ can also become a performance bottleneck if you do it a million times in the code path. In such a case, it will not be that i++ is non-performant but it is the code that uses it, is the problem.
For example if you have this wait for threads in a receiver thread pool in a server, you might as well looking at very low throughputs. So, without the context/code it is very hard to tell whether it actually is a problem or not.