org.jgroups.protocols
Class QUEUE

java.lang.Object
  extended by org.jgroups.stack.Protocol
      extended by org.jgroups.protocols.QUEUE

public class QUEUE
extends Protocol

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.

Author:
Bela Ban

Nested Class Summary
static interface QUEUE.Observer
           
 
Field Summary
 
Fields inherited from class org.jgroups.stack.Protocol
down_handler, down_prot, down_queue, down_thread, down_thread_prio, log, observer, props, stack, stats, trace, up_handler, up_prot, up_queue, up_thread, up_thread_prio, warn
 
Constructor Summary
QUEUE()
           
 
Method Summary
 void down(Event evt)
          An event is to be sent down the stack.
 java.util.Vector getDownVector()
           
 java.lang.String getName()
          All protocol names have to be unique !
 boolean getQueueingDown()
           
 boolean getQueueingUp()
           
 java.util.Vector getUpVector()
           
 java.util.Vector providedDownServices()
          List of events that are provided to layers below (they will be handled when sent down from below).
 java.util.Vector providedUpServices()
          List of events that are provided to layers above (they will be handled when sent down from above).
 void setObserver(QUEUE.Observer observer)
          Only 1 observer is allowed.
 void up(Event evt)
          Queues or passes up events.
 
Methods inherited from class org.jgroups.stack.Protocol
destroy, downThreadEnabled, dumpStats, enableStats, getDownProtocol, getDownQueue, getProperties, getUpProtocol, getUpQueue, handleSpecialDownEvent, init, isTrace, isWarn, passDown, passUp, printStats, receiveDownEvent, receiveUpEvent, requiredDownServices, requiredUpServices, resetStats, setDownProtocol, setObserver, setProperties, setPropertiesInternal, setProtocolStack, setTrace, setUpProtocol, setWarn, start, startDownHandler, startUpHandler, statsEnabled, stop, stopInternal, upThreadEnabled
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

QUEUE

public QUEUE()
Method Detail

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)


getUpVector

public java.util.Vector getUpVector()

getDownVector

public java.util.Vector getDownVector()

getQueueingUp

public boolean getQueueingUp()

getQueueingDown

public boolean getQueueingDown()

getName

public java.lang.String getName()
All protocol names have to be unique !

Specified by:
getName in class Protocol

providedUpServices

public java.util.Vector providedUpServices()
Description copied from class: Protocol
List of events that are provided to layers above (they will be handled when sent down from above).

Overrides:
providedUpServices in class Protocol
Returns:
Vector (of Integers)

providedDownServices

public java.util.Vector providedDownServices()
Description copied from class: Protocol
List of events that are provided to layers below (they will be handled when sent down from below).

Overrides:
providedDownServices in class Protocol
Returns:
Vector (of Integers)

up

public void up(Event evt)
Queues or passes up events. No queue sync. necessary, as this method is never called concurrently.

Overrides:
up in class Protocol

down

public void down(Event evt)
Description copied from class: Protocol
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().

Overrides:
down in class Protocol


Copyright ? 1998-2005 Bela Ban. All Rights Reserved.