Package org.jgroups.protocols

Class RSVP

  • public class RSVP
extends Protocol
    Protocol which implements synchronous messages (https://issues.jboss.org/browse/JGRP-1389). A send of a message M with flag RSVP set will block until all non-faulty recipients (one for unicasts, N for multicasts) have acked M, or until a timeout kicks in.
    Since:
    3.1
    Author:
    Bela Ban

    • Field Detail

      • timeout

        protected long timeout

      • throw_exception_on_timeout

        protected boolean throw_exception_on_timeout

      • ack_on_delivery

        protected boolean ack_on_delivery

      • resend_interval

        protected long resend_interval

      • current_id

        protected short current_id
        ID to be used to identify messages. Short.MAX_VALUE (ca 32K plus 32K negative) should be enough, and wrap-around shouldn't be an issue. Using Message.Flag.RSVP should be the exception, not the rule...

      • members

        protected volatile java.util.List<Address> members

      • local_addr

        protected Address local_addr

      • ids

        protected final java.util.concurrent.ConcurrentMap<java.lang.Short,​RSVP.Entry> ids
        Used to store IDs and their acks

      • resend_task

        protected java.util.concurrent.Future<?> resend_task

      • handle_unicasts

        protected boolean handle_unicasts

    • Constructor Detail

      • RSVP

        public RSVP()

    • Method Detail

      • getPendingRsvpRequests

        public int getPendingRsvpRequests()

      • init

        public void init()
          throws java.lang.Exception
        Description copied from class: Protocol
        Called after instance has been created (null constructor) and before protocol is started. Properties are already set. Other protocols are not yet connected and events cannot yet be sent.
        Overrides:
        init in class Protocol
        Throws:
        java.lang.Exception - Thrown if protocol cannot be initialized successfully. This will cause the ProtocolStack to fail, so the channel constructor will throw an exception

      • start

        public void start()
           throws java.lang.Exception
        Description copied from class: Protocol
        This method is called on a JChannel.connect(String). Starts work. Protocols are connected and queues are ready to receive events. Will be called from bottom to top. This call will replace the START and START_OK events.
        Overrides:
        start in class Protocol
        Throws:
        java.lang.Exception - Thrown if protocol cannot be started successfully. This will cause the ProtocolStack to fail, so JChannel.connect(String) will throw an exception

      • stop

        public void stop()
        Description copied from class: Protocol
        This method is called on a JChannel.disconnect(). Stops work (e.g. by closing multicast socket). Will be called from top to bottom. This means that at the time of the method invocation the neighbor protocol below is still working. This method will replace the STOP, STOP_OK, CLEANUP and CLEANUP_OK events. The ProtocolStack guarantees that when this method is called all messages in the down queue will have been flushed
        Overrides:
        stop in class Protocol

      • down

        public java.lang.Object down​(Event evt)
        Description copied from class: Protocol
        An event is to be sent down the stack. A protocol 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 protocol may need to add a header to it (or do nothing at all) before sending it down the stack using down_prot.down().
        Overrides:
        down in class Protocol

      • down

        public java.lang.Object down​(Message msg)
        Description copied from class: Protocol
        A message is sent down the stack. Protocols may examine the message and do something (e.g. add a header) with it before passing it down.
        Overrides:
        down in class Protocol

      • up

        public java.lang.Object up​(Event evt)
        Description copied from class: Protocol
        An event was received from the protocol below. Usually the current protocol 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 down_prot.down() or c) the event (or another event) is sent up the stack using up_prot.up().
        Overrides:
        up in class Protocol

      • up

        public java.lang.Object up​(Message msg)
        Description copied from class: Protocol
        A single message was received. Protocols may examine the message and do something (e.g. add a header) with it before passing it up.
        Overrides:
        up in class Protocol

      • up

        public void up​(MessageBatch batch)
        Description copied from class: Protocol
        Sends up a multiple messages in a MessageBatch. The sender of the batch is always the same, and so is the destination (null == multicast messages). Messages in a batch can be OOB messages, regular messages, or mixed messages, although the transport itself will create initial MessageBatches that contain only either OOB or regular messages.

        The default processing below sends messages up the stack individually, based on a matching criteria (calling Protocol.accept(org.jgroups.Message)), and - if true - calls Protocol.up(org.jgroups.Event) for that message and removes the message. If the batch is not empty, it is passed up, or else it is dropped.

        Subclasses should check if there are any messages destined for them (e.g. using MessageBatch.getMatchingMessages(short,boolean)), then possibly remove and process them and finally pass the batch up to the next protocol. Protocols can also modify messages in place, e.g. ENCRYPT could decrypt all encrypted messages in the batch, not remove them, and pass the batch up when done.

        Overrides:
        up in class Protocol
        Parameters:
        batch - The message batch

      • handleView

        protected void handleView​(View view)

      • handleResponse

        protected void handleResponse​(Address member,
                              short id)

      • sendResponse

        protected void sendResponse​(Address dest,
                            short id)

      • getNextId

        protected short getNextId()

      • startResendTask

        protected void startResendTask()

      • stopResendTask

        protected void stopResendTask()

      • isResendTaskRunning

        protected boolean isResendTaskRunning()