first-class synchronization barriers
Our purpose is to promote a second-class mechanism --- the synchronization barrier --- to a first-class value. We introduce the synchron, a novel synchronization mechanism that enables the coordination of a dynamically varying set of concurrent threads that share access to a first-class synchronization token. We demonstrate how synchrons can be used to modularly manage resources in cases where existing techniques are either inapplicable or non-modular. In particular, synchronized lazy aggregates enable the first space-efficient aggregate data decomposition of a wide range of algorithms. We also introduce explicit-demand graph reduction , a new semantic framework that we have developed to describe concurrency and explain the meaning of a synchron rendezvous.
synchronization barrier value coordination concurrency thread sharing access demonstrate management resource aggregate data decomposition algorithm graph semantic mean  framework  efficiency space modular class