org.jgroups.blocks
public class VotingAdapter extends Object implements MessageListener, MembershipListener, VoteResponseProcessor
Decree is an object that has some semantic meaning within the application.
Each voting listener receives a decree and can respond with either
true
or false. If the decree has no meaning for the voting
listener, it is required to throw VoteException. In this case
this specific listener will be excluded from the voting on the specified
decree. After performing local voting, this voting adapter sends the request
back to the originator of the voting process. Originator receives results
from each node and decides if all voting process succeeded or not depending
on the consensus type specified during voting.
Version: $Id: VotingAdapter.java,v 1.8 2005/06/08 15:56:54 publicnmi Exp $
Nested Class Summary | |
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static class | VotingAdapter.FailureVoteResult
Class that represents a result of local voting on the failed node. |
static class | VotingAdapter.VoteResult
This class represents the result of local voting. |
Field Summary | |
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protected Log | log |
static int | VOTE_ALL
This consensus type means that at least one positive vote and no negative
votes are required for the voting to succeed. |
static int | VOTE_ANY
This consensus type means that at least one positive vote is required
for the voting to succeed. |
static int | VOTE_MAJORITY
This consensus type means that number of positive votes should be greater
than number of negative votes. |
Constructor Summary | |
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VotingAdapter(Channel channel)
Creates an instance of the VoteChannel that uses JGroups
for communication between group members. | |
VotingAdapter(PullPushAdapter adapter, Serializable id) |
Method Summary | |
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void | addVoteListener(VotingListener listener)
Adds voting listener. |
void | block()
Blocks the channel until the ViewAccepted is invoked. |
static String | getConsensusStr(int consensusType)
Convert consensus type into string representation. |
byte[] | getState()
Get the channel state.
|
VotingAdapter.VoteResult | localVote(Object decree)
This method performs voting on the specific decree between all
local voteListeners. |
boolean | processResponses(RspList responses, int consensusType, Object decree)
Processes the response list and makes a decision according to the
type of the consensus for current voting.
|
void | receive(Message msg)
Receive the message. |
void | removeVoteListener(VotingListener listener)
Removes voting listener. |
void | setState(byte[] state)
Set the channel state. |
void | suspect(Address suspected)
Callback for notification that one node is suspected |
void | viewAccepted(View newView)
Callback for notification about the new view of the group. |
boolean | vote(Object decree, int consensusType, long timeout)
Performs actual voting on the VoteChannel using the JGroups
facilities for communication. |
boolean | vote(Object decree, int consensusType, long timeout, VoteResponseProcessor voteResponseProcessor)
Performs actual voting on the VoteChannel using the JGroups
facilities for communication. |
boolean | vote(Object decree, long timeout)
Vote on the specified decree requiring all nodes to vote.
|
boolean | vote(Object decree, long timeout, VoteResponseProcessor voteResponseProcessor)
Vote on the specified decree requiring all nodes to vote.
|
Parameters: channel JGroups channel.
Parameters: consensusType type of the consensus.
Returns: string representation of the consensus type.
Returns: always null
, we do not have any group-shared
state.
Note: we do not support voting in case of Byzantine failures, i.e. when the node responds with the fault message.
Parameters: msg message to check.
Parameters: decree decree on which nodes should vote. timeout time during which nodes can vote.
Returns: true
if nodes agreed on a decree, otherwise
false
Throws: ChannelException if something went wrong.
Parameters: decree decree on which nodes should vote. timeout time during which nodes can vote. voteResponseProcessor processor which will be called for every response that is received.
Returns: true
if nodes agreed on a decree, otherwise
false
Throws: ChannelException if something went wrong.