Hashed wheel timers – A short intro.
The Hashed wheel timer is a very interesting data structure used widely especially in network servers. Their low over memory over head and reasonable efficiency guarantees are a good match for servers handling millions of connections with a timer per connection. We will not spend too much time describing how they work, instead we will look at a few implementations and try to evaulate their relative trade-offs. More information about hashed-wheel-timers can be found here.