If you enforce that the buffer size is a power of 2 you just use a mask to do the
reply if (next_head == buffer.size())
next_head = 0;
If it's a power of two, you don't need the branch at all. Let the unsigned index wrap.
replyYou ultimately need a mask to access the correct slot in the ring. But it's true that you can leave unmasked values in your reader/writer indices.
replyInteresting, I've never heard about anybody using this. Maybe a bit unreadable? But yeah, should work :)
replyI believe ConcurrencyKit's impl does this.
replyhttps://github.com/concurrencykit/ck/blob/master/include/ck_...
See https://fgiesen.wordpress.com/2012/07/21/the-magic-ring-buff...
which takes it even further :)
replyNice one!
replyIndeed that's true. That extra constraint enables further optimization
replyIt's mentioned in the post, but worth reiterating!
This was, in fact, mentioned in the article.
reply