||A ClassQueueElementIF represents an event with an associated 'class'
used for class-based admission control.
||ConfigDataIF is used to pass configuration arguments to stages.
||Enqueue predicates allow users to specify a method that will
'screen' elements being enqueued onto a sink, either accepting or
||An EventHandlerIF represents an event handler - the basic unit of
computation in SandStorm.
||ManagerIF represents the system manger, which provides various
runtime services to applications, such as access to other stages.
||An object which implements ProfilableIF can be profiled by
||A ProfilerIF is responsible for profiling the behavior of the system
||A QueueElementIF represents an event which is placed on, or taken
off of, an event queue.
||A QueueIF implements a finite-length event queue.
||This is an empty interface that must be implemented by all classes
representing signal events.
||This class defines an interface for delivery of systemwide 'signals',
informational events that stages may wish to use for initialization
||This is an empty class used to indicate to the system that the
given event handler should be single-threaded.
||A SinkIF implements the 'sink' end of a finite-length event queue:
it supports enqueue operations only.
||A SourceIF implements the 'source side' of an event queue: it supports
dequeue operations only.
||A StageIF represents a handle to an application stage.
||This exception can be thrown if an inappropriate queue element
is pushed onto a SinkIF.
||This is a generic exception which an event handler can throw during
||This exception is thrown if a sink as requested by a call to
StageIF.getSink() does not exist.
||This exception is thrown if a stage as requested by a call to
ManagerIF.getStage() does not exist.
||This exception is thrown if one attempts to enqueue a new element
onto a sink which is closed.
||This is a generic exception which a sink can generate.
||This exception is thrown if a SinkIF is full; that is, that no
more entries can be pushed into the SinkIF immediately.
||This exception is thrown if a stage is created (via ManagerIF.createStage)
with a name that conflicts with another stage.
||This exception can be thrown if an unknown event type was received
by a stage.