org.jgroups.protocols
Class QUEUE
Queuing layer. Upon reception of event START_QUEUEING, all events traveling through
this layer upwards/downwards (depending on direction of event) will be queued. Upon
reception of a STOP_QUEUEING event, all events will be released. Finally, the
queueing flag is reset.
When queueing, only event STOP_QUEUEING (received up or downwards) will be allowed
to release queueing.
- Bela Ban
down_handler , down_prot , down_queue , down_thread , down_thread_prio , log , observer , props , stack , up_handler , up_prot , up_queue , up_thread , up_thread_prio |
destroy , down , getDownProtocol , getDownQueue , getName , getProperties , getUpProtocol , getUpQueue , handleSpecialDownEvent , init , passDown , passUp , providedDownServices , providedUpServices , receiveDownEvent , receiveUpEvent , requiredDownServices , requiredUpServices , setDownProtocol , setObserver , setProperties , setPropertiesInternal , setProtocolStack , setUpProtocol , start , startDownHandler , startUpHandler , stop , stopInternal , up |
down
public void down(Event evt)
An event is to be sent down the stack. The layer may want to examine its type and perform
some action on it, depending on the event's type. If the event is a message MSG, then
the layer may need to add a header to it (or do nothing at all) before sending it down
the stack using passDown()
. In case of a GET_ADDRESS event (which tries to
retrieve the stack's address from one of the bottom layers), the layer may need to send
a new response event back up the stack using passUp()
.
- down in interface Protocol
getDownVector
public Vector getDownVector()
getName
public String getName()
All protocol names have to be unique !
- getName in interface Protocol
getQueueingDown
public boolean getQueueingDown()
getQueueingUp
public boolean getQueueingUp()
getUpVector
public Vector getUpVector()
providedDownServices
public Vector providedDownServices()
List of events that are provided to layers below (they will be handled when sent down from
below).
- providedDownServices in interface Protocol
- Vector (of Integers)
providedUpServices
public Vector providedUpServices()
List of events that are provided to layers above (they will be handled when sent down from
above).
- providedUpServices in interface Protocol
- Vector (of Integers)
setObserver
public void setObserver(QUEUE.Observer observer)
Only 1 observer is allowed. More than one might slow down the system. Will be called
when an event is queued (up or down)
up
public void up(Event evt)
Queues or passes up events. No queue sync. necessary, as this method is never called
concurrently.
- up in interface Protocol
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