Package org.jgroups.blocks

Class MessageDispatcher

java.lang.Object

org.jgroups.blocks.MessageDispatcher

All Implemented Interfaces:

RequestHandler

Direct Known Subclasses:

MuxMessageDispatcher, RpcDispatcher

public class MessageDispatcher
extends Object
implements RequestHandler

Provides synchronous and asynchronous message sending with request-response correlation; i.e., matching responses with the original request. It also offers push-style message reception (by internally using the PullPushAdapter).

Channels are simple patterns to asynchronously send a receive messages. However, a significant number of communication patterns in group communication require synchronous communication. For example, a sender would like to send a message to the group and wait for all responses. Or another application would like to send a message to the group and wait only until the majority of the receivers have sent a response, or until a timeout occurred. MessageDispatcher offers a combination of the above pattern with other patterns.

Used on top of channel to implement group requests. Client's handle() method is called when request is received. Is the equivalent of RpcProtocol on the application instead of protocol level.

Author:

Bela Ban

Field Summary

Fields

Modifier and Type	Field	Description
protected PullPushAdapter	adapter
protected Channel	channel
protected RequestCorrelator	corr
protected org.jgroups.blocks.MessageDispatcher.PullPushHandler	handler
protected boolean	hardware_multicast_supported
protected Serializable	id
protected Address	local_addr
protected final Log	log
protected final Collection<Address>	members
protected MembershipListener	membership_listener
protected MessageListener	msg_listener
protected org.jgroups.blocks.MessageDispatcher.ProtocolAdapter	prot_adapter
protected RequestHandler	req_handler
protected org.jgroups.blocks.MessageDispatcher.TransportAdapter	transport_adapter

Constructor Summary

Constructors

Constructor	Description
MessageDispatcher()
MessageDispatcher(PullPushAdapter adapter, Serializable id, MessageListener l, MembershipListener l2)	Deprecated.
MessageDispatcher(PullPushAdapter adapter, Serializable id, MessageListener l, MembershipListener l2, RequestHandler req_handler)	Deprecated.
MessageDispatcher(PullPushAdapter adapter, Serializable id, MessageListener l, MembershipListener l2, RequestHandler req_handler, boolean concurrent_processing)	Deprecated.
MessageDispatcher(Channel channel, MessageListener l, MembershipListener l2)
MessageDispatcher(Channel channel, MessageListener l, MembershipListener l2, boolean deadlock_detection)	Deprecated.
MessageDispatcher(Channel channel, MessageListener l, MembershipListener l2, boolean deadlock_detection, boolean concurrent_processing)	Deprecated.
MessageDispatcher(Channel channel, MessageListener l, MembershipListener l2, RequestHandler req_handler)
MessageDispatcher(Channel channel, MessageListener l, MembershipListener l2, RequestHandler req_handler, boolean deadlock_detection)	Deprecated.
MessageDispatcher(Channel channel, MessageListener l, MembershipListener l2, RequestHandler req_handler, boolean deadlock_detection, boolean concurrent_processing)	Deprecated.

Method Summary

Modifier and Type	Method	Description
protected GroupRequest	cast(Collection<Address> dests, Message msg, RequestOptions options, boolean block_for_results)
RspList	castMessage(Collection<Address> dests, Message msg, RequestOptions options)	Sends a message to the members listed in dests.
RspList	castMessage(Vector dests, Message msg, int mode, long timeout)	Deprecated.
RspList	castMessage(Vector dests, Message msg, int mode, long timeout, boolean use_anycasting)	Deprecated.
RspList	castMessage(Vector dests, Message msg, int mode, long timeout, boolean use_anycasting, RspFilter filter)	Deprecated.
NotifyingFuture<RspList>	castMessageWithFuture(Collection<Address> dests, Message msg, RequestOptions options)
NotifyingFuture<RspList>	castMessageWithFuture(Vector dests, Message msg, int mode, long timeout, boolean use_anycasting, RspFilter filter)	Deprecated.
protected void	correlatorStarted()
protected RequestCorrelator	createRequestCorrelator(Object transport, RequestHandler handler, Address local_addr)
void	done(long req_id)
Channel	getChannel()	Offers access to the underlying Channel.
boolean	getConcurrentProcessing()	Deprecated.
boolean	getDeadlockDetection()	Deprecated.
protected Collection	getMembers()	Returns a copy of members
MessageListener	getMessageListener()	Gives access to the currently configured MessageListener.
UpHandler	getProtocolAdapter()
Object	handle(Message msg)
protected void	installUpHandler(UpHandler handler, boolean canReplace)	Sets the given UpHandler as the UpHandler for the channel, or, if the channel already has a Muxer installed as it's UpHandler, sets the given handler as the Muxer's default handler.
void	send(Message msg)	Deprecated.
Object	sendMessage(Message msg, int mode, long timeout)	Deprecated. Use sendMessage(org.jgroups.Message, RequestOptions) instead
Object	sendMessage(Message msg, RequestOptions opts)
<T> NotifyingFuture<T>	sendMessageWithFuture(Message msg, int mode, long timeout)	Deprecated.
<T> NotifyingFuture<T>	sendMessageWithFuture(Message msg, RequestOptions options)
void	setChannel(Channel ch)
void	setConcurrentProcessing(boolean flag)	Deprecated.
void	setDeadlockDetection(boolean flag)	Deprecated.
final void	setMembershipListener(MembershipListener l)
final void	setMessageListener(MessageListener l)
final void	setRequestHandler(RequestHandler rh)
void	start()
void	stop()

Methods inherited from class java.lang.Object

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

Field Details

channel

protected Channel channel

corr

protected RequestCorrelator corr

msg_listener

protected MessageListener msg_listener

membership_listener

protected MembershipListener membership_listener

req_handler

protected RequestHandler req_handler

prot_adapter

protected org.jgroups.blocks.MessageDispatcher.ProtocolAdapter prot_adapter

transport_adapter

protected org.jgroups.blocks.MessageDispatcher.TransportAdapter transport_adapter

members

protected final Collection<Address> members

local_addr

protected Address local_addr

adapter

protected PullPushAdapter adapter

handler

protected org.jgroups.blocks.MessageDispatcher.PullPushHandler handler

id

protected Serializable id

log

protected final Log log

hardware_multicast_supported

protected boolean hardware_multicast_supported

Constructor Details

MessageDispatcher

public MessageDispatcher()

MessageDispatcher

public MessageDispatcher(Channel channel,
 MessageListener l,
 MembershipListener l2)

MessageDispatcher

@Deprecated
public MessageDispatcher(Channel channel,
 MessageListener l,
 MembershipListener l2,
 boolean deadlock_detection)

Deprecated.

MessageDispatcher

@Deprecated
public MessageDispatcher(Channel channel,
 MessageListener l,
 MembershipListener l2,
 boolean deadlock_detection,
 boolean concurrent_processing)

Deprecated.

MessageDispatcher

public MessageDispatcher(Channel channel,
 MessageListener l,
 MembershipListener l2,
 RequestHandler req_handler)

MessageDispatcher

@Deprecated
public MessageDispatcher(Channel channel,
 MessageListener l,
 MembershipListener l2,
 RequestHandler req_handler,
 boolean deadlock_detection)

Deprecated.

MessageDispatcher

@Deprecated
public MessageDispatcher(Channel channel,
 MessageListener l,
 MembershipListener l2,
 RequestHandler req_handler,
 boolean deadlock_detection,
 boolean concurrent_processing)

Deprecated.

MessageDispatcher

@Deprecated
public MessageDispatcher(PullPushAdapter adapter,
 Serializable id,
 MessageListener l,
 MembershipListener l2)

Deprecated.

MessageDispatcher

@Deprecated
public MessageDispatcher(PullPushAdapter adapter,
 Serializable id,
 MessageListener l,
 MembershipListener l2,
 RequestHandler req_handler)

Deprecated.

MessageDispatcher

@Deprecated
public MessageDispatcher(PullPushAdapter adapter,
 Serializable id,
 MessageListener l,
 MembershipListener l2,
 RequestHandler req_handler,
 boolean concurrent_processing)

Deprecated.

Method Details

getProtocolAdapter

public UpHandler getProtocolAdapter()

getMembers

protected Collection getMembers()

Returns a copy of members

getDeadlockDetection

@Deprecated
public boolean getDeadlockDetection()

Deprecated.

setDeadlockDetection

@Deprecated
public void setDeadlockDetection(boolean flag)

Deprecated.

getConcurrentProcessing

@Deprecated
public boolean getConcurrentProcessing()

Deprecated.

setConcurrentProcessing

@Deprecated
public void setConcurrentProcessing(boolean flag)

Deprecated.

start

public void start()

createRequestCorrelator

protected RequestCorrelator createRequestCorrelator(Object transport,
 RequestHandler handler,
 Address local_addr)

correlatorStarted

protected void correlatorStarted()

stop

public void stop()

setMessageListener

public final void setMessageListener(MessageListener l)

getMessageListener

public MessageListener getMessageListener()

Gives access to the currently configured MessageListener. Returns null if there is no configured MessageListener.

setMembershipListener

public final void setMembershipListener(MembershipListener l)

setRequestHandler

public final void setRequestHandler(RequestHandler rh)

getChannel

public Channel getChannel()

Offers access to the underlying Channel.

Returns:

a reference to the underlying Channel.

setChannel

public void setChannel(Channel ch)

installUpHandler

protected void installUpHandler(UpHandler handler,
 boolean canReplace)

Sets the given UpHandler as the UpHandler for the channel, or, if the channel already has a Muxer installed as it's UpHandler, sets the given handler as the Muxer's default handler. If the relevant handler is already installed, the canReplace controls whether this method replaces it (after logging a WARN) or simply leaves handler uninstalled.

Passing false as the canReplace value allows callers to use this method to install defaults without concern about inadvertently overriding

Parameters:

handler - the UpHandler to install

canReplace - true if an existing Channel upHandler or Muxer default upHandler can be replaced; false if this method shouldn't install

send

@Deprecated
public void send(Message msg)
          throws ChannelNotConnectedException,
ChannelClosedException

Deprecated.

Throws:

ChannelNotConnectedException

ChannelClosedException

castMessage

@Deprecated
public RspList castMessage(Vector dests,
 Message msg,
 int mode,
 long timeout)

Deprecated.

castMessage

@Deprecated
public RspList castMessage(Vector dests,
 Message msg,
 int mode,
 long timeout,
 boolean use_anycasting)

Deprecated.

castMessage

@Deprecated
public RspList castMessage(Vector dests,
 Message msg,
 int mode,
 long timeout,
 boolean use_anycasting,
 RspFilter filter)

Deprecated.

castMessage

public RspList castMessage(Collection<Address> dests,
 Message msg,
 RequestOptions options)

Sends a message to the members listed in dests. If dests is null, the message is sent to all current group members.

Parameters:

dests - A list of group members. The message is sent to all members of the current group if null

msg - The message to be sent

options - A set of options that govern the call. See RequestOptions for details

Returns:

Since:

2.9

castMessageWithFuture

@Deprecated
public NotifyingFuture<RspList> castMessageWithFuture(Vector dests,
 Message msg,
 int mode,
 long timeout,
 boolean use_anycasting,
 RspFilter filter)

Deprecated.

castMessageWithFuture

public NotifyingFuture<RspList> castMessageWithFuture(Collection<Address> dests,
 Message msg,
 RequestOptions options)

cast

protected GroupRequest cast(Collection<Address> dests,
 Message msg,
 RequestOptions options,
 boolean block_for_results)

done

public void done(long req_id)

sendMessage

@Deprecated
public Object sendMessage(Message msg,
 int mode,
 long timeout)
                   throws TimeoutException,
SuspectedException

Deprecated.

Use sendMessage(org.jgroups.Message, RequestOptions) instead

Sends a message to a single member (destination = msg.dest) and returns the response. The message's destination must be non-zero !

Throws:

TimeoutException

SuspectedException

sendMessage

public Object sendMessage(Message msg,
 RequestOptions opts)
                   throws TimeoutException,
SuspectedException

Throws:

TimeoutException

SuspectedException

sendMessageWithFuture

@Deprecated
public <T> NotifyingFuture<T> sendMessageWithFuture(Message msg,
 int mode,
 long timeout)
                                             throws TimeoutException,
SuspectedException

Deprecated.

Throws:

TimeoutException

SuspectedException

sendMessageWithFuture

public <T> NotifyingFuture<T> sendMessageWithFuture(Message msg,
 RequestOptions options)
                                             throws TimeoutException,
SuspectedException

Throws:

TimeoutException

SuspectedException

handle

public Object handle(Message msg)

Specified by:

handle in interface RequestHandler