org.javagroups.protocols.pbcast
Class PBCAST
java.lang.Object
|
+--org.javagroups.stack.Protocol
|
+--org.javagroups.protocols.pbcast.PBCAST
- All Implemented Interfaces:
- java.lang.Runnable
- public class PBCAST
- extends Protocol
- implements java.lang.Runnable
Implementation of probabilistic broadcast. Sends group messages via unreliable multicast. Gossips regularly to
a random subset of group members to retransmit missing messages. Gossiping is used both for bringing all
members to the same state (having received the same messages) and to garbage-collect messages seen by all members
(gc is piggybacked in gossip messages). See DESIGN for more details.
- Author:
- Bela Ban
Fields inherited from class org.javagroups.stack.Protocol |
down_handler, down_prot, down_queue, down_thread, observer, props, stack, up_handler, up_prot, up_queue, up_thread |
Method Summary |
void |
down(Event evt)
An event is to be sent down the stack. |
java.lang.String |
getName()
|
java.util.Vector |
providedUpServices()
List of events that are provided to layers above (they will be handled when sent down from
above). |
void |
run()
Gossip thread. |
boolean |
setProperties(java.util.Properties props)
Setup the Protocol instance acording to the configuration string |
void |
up(Event evt)
An event was received from the layer below. |
Methods inherited from class org.javagroups.stack.Protocol |
getDownProtocol, getDownQueue, getProperties, getUpProtocol, getUpQueue, init, passDown, passUp, providedDownServices, receiveDownEvent, receiveUpEvent, requiredDownServices, requiredUpServices, setDownProtocol, setObserver, setPropertiesInternal, setProtocolStack, setUpProtocol, startDownHandler, startUpHandler, stopInternal |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
PBCAST
public PBCAST()
getName
public java.lang.String getName()
- Overrides:
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
- Following copied from class:
org.javagroups.stack.Protocol
- Returns:
- Vector (of Integers)
up
public void up(Event evt)
- Description copied from class:
Protocol
- An event was received from the layer below. Usually the current layer will want to examine
the event type and - depending on its type - perform some computation
(e.g. removing headers from a MSG event type, or updating the internal membership list
when receiving a VIEW_CHANGE event).
Finally the event is either a) discarded, or b) an event is sent down
the stack using
passDown()
or c) the event (or another event) is sent up
the stack using passUp()
.
- 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
run
public void run()
- Gossip thread. Sends gossips containing a message digest every
gossip_interval
msecs
- Specified by:
run
in interface java.lang.Runnable
setProperties
public boolean setProperties(java.util.Properties props)
- Setup the Protocol instance acording to the configuration string
- Overrides:
setProperties
in class Protocol
Copyright © 2001,2002 www.javagroups.com . All Rights Reserved.