| java.lang.Object
 java.lang.Thread
org.jgroups.stack.UpHandler
org.jgroups.stack.MessageProtocol
All known Subclasses: org.jgroups.protocols.FLOW_CONTROL, org.jgroups.protocols.MessageProtocolEXAMPLE, org.jgroups.stack.RpcProtocol,
| MessageProtocol | | abstract public class MessageProtocol extends Protocol implements RequestHandler(Code) | | Based on Protocol, but incorporates RequestCorrelator and GroupRequest: the latter can
be used to mcast messages to all members and receive their reponses.
A protocol based on this template can send messages to all members and receive all, a single,
n, or none responses. Requests directed towards the protocol can be handled by overriding
method Handle.
Requests and responses are in the form of Messages, which would typically need to
contain information pertaining to the request/response, e.g. in the form of objects contained
in the message. To use remote method calls, use RpcProtocol instead.
Typical use of of a MessageProtocol would be when a protocol needs to interact with
its peer protocols at each of the members' protocol stacks. A simple protocol like fragmentation,
which does not need to interact with other instances of fragmentation, may simply subclass
Protocol instead.
author:
Bela Ban |
| Method Summary | |
| public RspList | castMessage(Vector dests, Message msg, int mode, long timeout)
Cast a message to all members, and wait for mode responses. | | final public void | down(Event evt)
This message is not originated by this layer, therefore we can just
pass it down without having to go through the request correlator. | | public Object | handle(Message req)
Processes a request destined for this layer. | | protected boolean | handleDownEvent(Event evt)
Handle down event. | | protected boolean | handleUpEvent(Event evt)
Handle up event. | | public Object | sendMessage(Message msg, int mode, long timeout)
Sends a message to a single member (destination = msg.dest) and returns the response. | | public void | start()
| | public void | stop()
| | final public void | up(Event evt)
| | protected void | updateView(View new_view)
|
| castMessage | | public RspList castMessage(Vector dests, Message msg, int mode, long timeout)(Code) | | Cast a message to all members, and wait for mode responses. The responses are
returned in a response list, where each response is associated with its sender.
Uses GroupRequest.
Parameters:
dests - The members from which responses are expected. If it is null, replies from all membersare expected. The request itself is multicast to all members.
Parameters:
msg - The message to be sent to n members
Parameters:
mode - Defined in GroupRequest. The number of responses to wait for: - GET_FIRST: return the first response received.
- GET_ALL: wait for all responses (minus the ones from suspected members)
- GET_MAJORITY: wait for a majority of all responses (relative to the grp size)
- GET_ABS_MAJORITY: wait for majority (absolute, computed once)
- GET_N: wait for n responses (may block if n > group size)
- GET_NONE: wait for no responses, return immediately (non-blocking)
Parameters:
timeout - If 0: wait forever. Otherwise, wait for mode responsesor timeout time. RspList A list of responses. Each response is an Object and associatedto its sender. |
| down | | final public void down(Event evt)(Code) | | This message is not originated by this layer, therefore we can just
pass it down without having to go through the request correlator.
We do this ONLY for messages !
|
| handle | | public Object handle(Message req)(Code) | | Processes a request destined for this layer. The return value is sent as response.
|
| handleDownEvent | | protected boolean handleDownEvent(Event evt)(Code) | | Handle down event. Return false if it should not be passed down the stack.
|
| handleUpEvent | | protected boolean handleUpEvent(Event evt)(Code) | | Handle up event. Return false if it should not be passed up the stack.
|
| up | | final public void up(Event evt)(Code) | | Handle an event coming from the layer above
|
| updateView | | protected void updateView(View new_view)(Code) | | |
| Fields inherited from org.jgroups.stack.UpHandler | final protected Log log(Code)(Java Doc)
|
|
|