Barrier

AsyncBarrier is an asynchronous alternative of Barrier with some additional features:

• Post-phase action is asynchronous
• It is possible to wait for phase completion without signaling (use Wait method instead of SignalAndWait)
• It is possible to signal without waiting for phase completion

Last two features are possible because barrier implements IAsyncEvent interface which is common to all event-based synchronization primitives in .NEXT Threading library.