# Package org.apache.cassandra.utils.concurrent

Interface Summary
Interface | Description
--- | ---
WaitQueue.Signal | A Signal is a one-time-use mechanism for a thread to wait for notification that some condition state has transitioned that it may be interested in (and hence should check if it is).

Class Summary
Class | Description
--- | ---
OpOrder | A class for providing synchronization between producers and consumers that do not communicate directly with each other, but where the consumers need to process their work in contiguous batches.
OpOrder.Group | Represents a group of identically ordered operations, i.e.
SimpleCondition |
WaitQueue | A relatively easy to use utility for general purpose thread signalling.
WaitQueue.AbstractSignal | An abstract signal implementation