jgroup.relacs.gmi.protocols
Class Atomic

java.lang.Object
  jgroup.relacs.gmi.protocols.BasicDispatcher
      jgroup.relacs.gmi.protocols.Atomic

All Implemented Interfaces:

MulticastListener, ProtocolDispatcher

public class Atomic
extends BasicDispatcher
implements MulticastListener

Atomic represents a protocol that dispatch method invocations received through the local endpoint to all the other methods of the group, including the local server. Each message received is ordered according to a total order among all members of the group. The result from all members is returned to the local endpoint whom first received the method invocation request from some client, and one of results are selected and passed back to the client. Total ordering is accomplished using distributed agreement protocol similar to that of [Birman and Joseph 1987].

Since:

Jgroup 2.2

Author:

Hein Meling

Constructor Summary

Atomic(GroupInvocationDispatcher dispatcher, MulticastService mcast, MembershipService pgms)

Method Summary

java.lang.Object	deliverObject(java.lang.Object msg, MemberId sender, int seqNo) Upcall that is invoked by Jgroup to deliver a message msg, corresponding to a single serialized object.
java.lang.Object	deliverStream(java.io.InputStream msg, MemberId sender, int seqNo) Received a multicast message from a mediating endpoint for invocation dispatching at the local server.
InvocationResult	dispatch(java.io.InputStream in) Handle inbound request to the local endpoint with atomic invocation semantics.
java.lang.String	getProtocolName() Returns a string naming the protocol implemented by this multicast listener.

Methods inherited from class jgroup.relacs.gmi.protocols.BasicDispatcher

getIdentifier, setServer

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Atomic

public Atomic(GroupInvocationDispatcher dispatcher,
              MulticastService mcast,
              MembershipService pgms)

Method Detail

dispatch

public InvocationResult dispatch(java.io.InputStream in)
                          throws java.io.IOException

Handle inbound request to the local endpoint with atomic invocation semantics. The local endpoint will send a multicast message to all the other group members for method invocation dispatching at each members. They each return a result to the local endpoint, and one of these values are selected and returned to the client (GroupInvocationHandler).

Specified by:

dispatch in interface ProtocolDispatcher

Overrides:

dispatch in class BasicDispatcher

Parameters:

in - the method to invoke, encoded in the provided InputStream.

Returns:

the result of the method invocation.

Throws:

java.io.IOException - Raised if the method invocation read from the InputStream could not be executed for some reason.

See Also:

ProtocolDispatcher.dispatch(java.io.InputStream)

getProtocolName

public java.lang.String getProtocolName()

Description copied from interface: MulticastListener

Returns a string naming the protocol implemented by this multicast listener.

Specified by:

getProtocolName in interface MulticastListener

deliverStream

public java.lang.Object deliverStream(java.io.InputStream msg,
                                      MemberId sender,
                                      int seqNo)

Received a multicast message from a mediating endpoint for invocation dispatching at the local server.

Specified by:

deliverStream in interface MulticastListener

Parameters:

msg - Atomic multicast message received

sender - the sender of the multicast message

seqNo - the sequence number of this multicast message

Returns:

The result of the atomic multicast invocation, or null if the invocation failed.

See Also:

MulticastListener.deliverStream(java.io.InputStream, jgroup.core.MemberId, int)

deliverObject

public java.lang.Object deliverObject(java.lang.Object msg,
                                      MemberId sender,
                                      int seqNo)

Description copied from interface: MulticastListener

Upcall that is invoked by Jgroup to deliver a message msg, corresponding to a single serialized object.

Specified by:

deliverObject in interface MulticastListener

Parameters:

msg - the object that was multicasted.

sender - the sender of the multicast message

seqNo - the sequence number of this multicast message

Returns:

an object that will be delivered to the invoker through the AckListener object specified when multicasting the message.