| Interface | Description | 
|---|---|
| Completable | 
 Interface that exposes a callback to indicate when an operation has been completed. 
 | 
| Emitter<T> | 
 Base interface for classes that emit data. 
 | 
| Class | Description | 
|---|---|
| CompletionAwareSubscriber<T> | 
 A  
Subscriber that tracks completion state using a AtomicBoolean. | 
| SingleThreadedBufferingSubscriber<T> | 
 A  
Subscriber designed to be used by a single thread that buffers incoming data for the purposes of managing
 back pressure. | 
| TypedSubscriber<T> | 
 A subscriber that is aware of the target type. 
 | 
| Enum | Description | 
|---|---|
| SingleThreadedBufferingSubscriber.BackPressureState | 
 Back pressure state. 
 |