Package org.jgroups.protocols

Class FORK

java.lang.Object
org.jgroups.stack.Protocol
org.jgroups.protocols.FORK
All Implemented Interfaces:
Lifecycle
public class FORK extends Protocol
The FORK protocol; multiplexes messages to different forks in a stack (https://issues.redhat.com/browse/JGRP-1613). See doc/design/FORK.txt for details
Since:
3.4

  • Field Details

    • ID

      public static short ID

    • config

      protected String config

    • process_state_events

      protected boolean process_state_events

    • unknownForkHandler

      private UnknownForkHandler unknownForkHandler

    • fork_stacks

      protected final ConcurrentMap<String,Protocol> fork_stacks

  • Constructor Details

    • FORK

      public FORK()

  • Method Details

    • setUnknownForkHandler

      public FORK setUnknownForkHandler(UnknownForkHandler unknownForkHandler)

    • getUnknownForkHandler

      public UnknownForkHandler getUnknownForkHandler()

    • getConfig

      public String getConfig()

    • setConfig

      public FORK setConfig(String c)

    • processStateEvents

      public boolean processStateEvents()

    • processStateEvents

      public FORK processStateEvents(boolean p)

    • get

      public Protocol get(String fork_stack_id)

    • putIfAbsent

      public Protocol putIfAbsent(String fork_stack_id, Protocol p)

    • remove

      public void remove(String fork_stack_id)

    • getForkStacks

      public int getForkStacks()

    • getForkStack

      public static ForkProtocolStack getForkStack(Protocol prot)

    • setAddress

      public <T extends Protocol> T setAddress(Address addr)
      Overrides:
      setAddress in class Protocol

    • init

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

    • up

      public 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 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(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.iterator(Predicate)), 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

    • getStateFromMainAndForkChannels

      protected void getStateFromMainAndForkChannels(Event evt)

    • getStateFrom

      protected void getStateFrom(JChannel channel, Protocol prot, String stack, String ch, DataOutputStream out) throws Exception
      Throws:
      Exception

    • setStateInMainAndForkChannels

      protected void setStateInMainAndForkChannels(InputStream in)

    • createForkStacks

      protected void createForkStacks(String config) throws Exception
      Throws:
      Exception

    • createForkStacks

      protected void createForkStacks(Map<String,List<ProtocolConfiguration>> protocols) throws Exception
      Throws:
      Exception

    • parse

      public void parse(XmlNode node) throws Exception
      Description copied from class: Protocol
      Called by the XML parser when subelements are found in the configuration of a protocol. This allows a protocol to define protocol-specific information and to parse it
      Overrides:
      parse in class Protocol
      Throws:
      Exception

    • createForkStack

      public ProtocolStack createForkStack(String fork_stack_id, List<Protocol> protocols, boolean initialize) throws Exception
      Returns the fork stack for fork_stack_id (if exitstent), or creates a new fork-stack from protocols and adds it into the hashmap of fork-stack (key is fork_stack_id). Method init() will be called on each protocol, from bottom to top.
      Parameters:
      fork_stack_id - The key under which the new fork-stack should be added to the fork-stacks hashmap
      protocols - A list of protocols from bottom to top to be inserted. They will be sandwiched between ForkProtocolStack (top) and ForkProtocol (bottom). The list can be empty (or null) in which case we won't create any protocols, but still have a separate fork-stack inserted.
      initialize - If false, the ref count 'inits' will not get incremented and init() won't be called. This is needed when creating a fork stack from an XML config inside of the FORK protocol. The protocols in the fork stack will only get initialized on the first ForkChannel creation
      Returns:
      The new ForkProtocolStack, or the existing stack (if present)
      Throws:
      Exception

    • getForkStream

      public static InputStream getForkStream(String config) throws IOException
      Throws:
      IOException