Class SFC

java.lang.Object
org.jgroups.stack.Protocol
org.jgroups.protocols.SFC

public class SFC extends Protocol
Simple flow control protocol. After max_credits bytes sent to the group (or an individual member), the sender blocks until it receives an ack from all members that they indeed received max_credits bytes. Design in doc/design/SimpleFlowControl.txt
Note that SFC supports only flow control for multicast messages; unicast flow control is not supported ! Use FC if unicast flow control is required.
Version:
$Id: SFC.java,v 1.19 2007/09/07 11:42:44 belaban Exp $
Author:
Bela Ban
  • Constructor Details

    • SFC

      public SFC()
  • Method Details

    • resetStats

      public void resetStats()
      Overrides:
      resetStats in class Protocol
    • getMaxCredits

      public long getMaxCredits()
    • getCredits

      public long getCredits()
    • getBytesSent

      public long getBytesSent()
    • getBlockings

      public long getBlockings()
    • getCreditRequestsSent

      public long getCreditRequestsSent()
    • getCreditRequestsReceived

      public long getCreditRequestsReceived()
    • getReplenishmentsReceived

      public long getReplenishmentsReceived()
    • getReplenishmentsSent

      public long getReplenishmentsSent()
    • getTotalBlockingTime

      public long getTotalBlockingTime()
    • getAverageBlockingTime

      public double getAverageBlockingTime()
    • dumpStats

      public Map<String,Object> dumpStats()
      Overrides:
      dumpStats in class Protocol
    • printBlockingTimes

      public String printBlockingTimes()
    • printReceived

      public String printReceived()
    • printPendingCreditors

      public String printPendingCreditors()
    • printPendingRequesters

      public String printPendingRequesters()
    • unblock

      public void unblock()
    • getName

      public final String getName()
      Specified by:
      getName in class Protocol
    • setProperties

      public boolean setProperties(Properties props)
      Description copied from class: Protocol
      Configures the protocol initially. A configuration string consists of name=value items, separated by a ';' (semicolon), e.g.:
       "loopback=false;unicast_inport=4444"
       
      Overrides:
      setProperties in class Protocol
    • down

      public Object down(Event evt)
      Description copied from class: Protocol
      An event is to be sent down the stack. The layer 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 layer may need to add a header to it (or do nothing at all) before sending it down the stack using down_prot.down(). In case of a GET_ADDRESS event (which tries to retrieve the stack's address from one of the bottom layers), the layer may need to send a new response event back up the stack using up_prot.up().
      Overrides:
      down in class Protocol
    • up

      public Object up(Event evt)
      Description copied from class: Protocol
      An event was received from the layer below. Usually the current layer 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
    • start

      public void start() throws Exception
      Description copied from class: Protocol
      This method is called on a Channel.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:
      Exception - Thrown if protocol cannot be started successfully. This will cause the ProtocolStack to fail, so Channel.connect(String) will throw an exception
    • stop

      public void stop()
      Description copied from class: Protocol
      This method is called on a Channel.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