Package org.snmp4j.util

Class MultiThreadedMessageDispatcher

java.lang.Object
org.snmp4j.util.MultiThreadedMessageDispatcher
All Implemented Interfaces:
MessageDispatcher, TransportListener
public class MultiThreadedMessageDispatcher extends Object implements MessageDispatcher
The MultiThreadedMessageDispatcher class is a decorator for any MessageDispatcher instances that processes incoming message with a supplied ThreadPool. The processing is thus parallelized on up to the size of the supplied thread pool threads.

In contrast to a MessageDispatcherImpl a MultiThreadedMessageDispatcher copies the incoming ByteBuffer for processMessage(TransportMapping sourceTransport, Address incomingAddress, ByteBuffer wholeMessage, TransportStateReference tmStateReference) to allow concurrent processing of the buffer.

Since:
1.0.2
Version:
2.0
Author:
Frank Fock

  • Constructor Details

    • MultiThreadedMessageDispatcher

      public MultiThreadedMessageDispatcher(WorkerPool workerPool, MessageDispatcher decoratedDispatcher)
      Creates a multi-threaded message dispatcher using the provided ThreadPool to concurrently process incoming messages that are forwarded to the supplied decorated MessageDispatcher.
      Parameters:
      workerPool - a WorkerPool instance (that can be shared). The worker pool has to be stopped externally.
      decoratedDispatcher - the decorated MessageDispatcher that must be multi-threading safe.

  • Method Details

    • getNextRequestID

      public int getNextRequestID()
      Description copied from interface: MessageDispatcher
      Gets the next unique request ID. The returned ID is unique across the last 2^31-1 IDs generated by this message dispatcher.
      Specified by:
      getNextRequestID in interface MessageDispatcher
      Returns:
      an integer value in the range 1..2^31-1. The returned ID can be used to map responses to requests send through this message dispatcher.

    • addMessageProcessingModel

      public void addMessageProcessingModel(MessageProcessingModel model)
      Description copied from interface: MessageDispatcher
      Adds a MessageProcessingModel to the dispatcher. In order to support a specific SNMP protocol version, the message dispatcher needs a message processing model to process messages before they can be dispatched.
      Specified by:
      addMessageProcessingModel in interface MessageDispatcher
      Parameters:
      model - a MessageProcessingModel instance.

    • removeMessageProcessingModel

      public void removeMessageProcessingModel(MessageProcessingModel model)
      Description copied from interface: MessageDispatcher
      Removes a previously added MessageProcessingModel from the dispatcher.
      Specified by:
      removeMessageProcessingModel in interface MessageDispatcher
      Parameters:
      model - a MessageProcessingModel instance.

    • getMessageProcessingModel

      public MessageProcessingModel getMessageProcessingModel(int messageProcessingModel)
      Description copied from interface: MessageDispatcher
      Gets the MessageProcessingModel for the supplied message processing model ID.
      Specified by:
      getMessageProcessingModel in interface MessageDispatcher
      Parameters:
      messageProcessingModel - a message processing model ID (see MessageProcessingModel.getID()).
      Returns:
      a MessageProcessingModel instance if the ID is known, otherwise null

    • addTransportMapping

      public void addTransportMapping(TransportMapping<? extends Address> transport)
      Description copied from interface: MessageDispatcher
      Adds a TransportMapping to the dispatcher. The transport mapping is used to send and receive messages to/from the network.
      Specified by:
      addTransportMapping in interface MessageDispatcher
      Parameters:
      transport - a TransportMapping instance.

    • removeTransportMapping

      public TransportMapping removeTransportMapping(TransportMapping<? extends Address> transport)
      Description copied from interface: MessageDispatcher
      Removes a previously added TransportMapping from the dispatcher.
      Specified by:
      removeTransportMapping in interface MessageDispatcher
      Parameters:
      transport - a TransportMapping instance.
      Returns:
      the TransportMapping instance supplied if it could be successfully removed, null otherwise.

    • getTransportMappings

      public Collection<TransportMapping> getTransportMappings()
      Description copied from interface: MessageDispatcher
      Gets the Collection of transport mappings in this message dispatcher.
      Specified by:
      getTransportMappings in interface MessageDispatcher
      Returns:
      a Collection with the registered transport mappings.

    • addCommandResponder

      public void addCommandResponder(CommandResponder listener)
      Description copied from interface: MessageDispatcher
      Adds a CommandResponder instance to the message dispatcher. Successfully processed SNMP messages will be presented to all command responder (in the order in which they have been added) until a responder uses the CommandResponderEvent.setProcessed(boolean processed) to set the processed status of the event to true.
      Specified by:
      addCommandResponder in interface MessageDispatcher
      Parameters:
      listener - a CommandResponder instance.

    • removeCommandResponder

      public void removeCommandResponder(CommandResponder listener)
      Description copied from interface: MessageDispatcher
      Removes a previously added CommandResponder instance from the message dispatcher.
      Specified by:
      removeCommandResponder in interface MessageDispatcher
      Parameters:
      listener - a CommandResponder instance.

    • sendPdu

      public PduHandle sendPdu(Target target, PDU pdu, boolean expectResponse) throws MessageException
      Description copied from interface: MessageDispatcher
      Sends a PDU to the supplied transport address. This method behaves like a call to MessageDispatcher.sendPdu(TransportMapping transportMapping, Target target, PDU pdu, boolean expectResponse) with transportMapping set to null.
      Specified by:
      sendPdu in interface MessageDispatcher
      Parameters:
      target - the target which identifies, transport address, message processing model, security model, security name and level.
      pdu - the SNMP Protocol Data Unit
      expectResponse - true if a response is expected and a state reference should be saved (if needed for the supplied message processing model).
      Returns:
      an PduHandle that uniquely identifies this request.
      Throws:
      MessageException - if sending of the PDU failed.

    • sendPdu

      public PduHandle sendPdu(TransportMapping transportMapping, Target target, PDU pdu, boolean expectResponse) throws MessageException
      Description copied from interface: MessageDispatcher
      Sends a PDU to the supplied transport address.
      Specified by:
      sendPdu in interface MessageDispatcher
      Parameters:
      transportMapping - the TransportMapping to be used to send the PDU. If transportMapping is null the message dispatcher will determine the appropriate transport mapping for the given transport address.
      target - the target which identifies, transport address, message processing model, security model, security name and level.
      pdu - the SNMP Protocol Data Unit
      expectResponse - true if a response is expected and a state reference should be saved (if needed for the supplied message processing model).
      Returns:
      an PduHandle that uniquely identifies this request.
      Throws:
      MessageException - if sending of the PDU failed.

    • sendPdu

      public PduHandle sendPdu(TransportMapping transportMapping, Target target, PDU pdu, boolean expectResponse, PduHandleCallback<PDU> callback) throws MessageException
      Description copied from interface: MessageDispatcher
      Sends a PDU to the supplied transport address and returns the PduHandle that uniquely identifies the request as response after the request has been sent and optional, if a PduHandleCallback is given, it returns also the PduHandle just before the request is sent through the the callback interface.
      Specified by:
      sendPdu in interface MessageDispatcher
      Parameters:
      transportMapping - the TransportMapping to be used to send the PDU. If transportMapping is null the message dispatcher will determine the appropriate transport mapping for the given transport address.
      target - the target which identifies, transport address, message processing model, security model, security name and level.
      pdu - the SNMP Protocol Data Unit
      expectResponse - true if a response is expected and a state reference should be saved (if needed for the supplied message processing model).
      callback - an optional callback instance that is informed (if not null) about the newly assigned PduHandle just before the message is sent out.
      Returns:
      an PduHandle that uniquely identifies this request.
      Throws:
      MessageException - if sending of the PDU failed.

    • returnResponsePdu

      public int returnResponsePdu(int messageProcessingModel, int securityModel, byte[] securityName, int securityLevel, PDU pdu, int maxSizeResponseScopedPDU, StateReference stateReference, StatusInformation statusInformation) throws MessageException
      Description copied from interface: MessageDispatcher
      Returns a response PDU to the sender of the corresponding request PDU.
      Specified by:
      returnResponsePdu in interface MessageDispatcher
      Parameters:
      messageProcessingModel - int
      securityModel - int
      securityName - byte[]
      securityLevel - int
      pdu - PDU
      maxSizeResponseScopedPDU - int
      stateReference - StateReference
      statusInformation - StatusInformation
      Returns:
      an MP error status or SnmpConstants.SNMP_MP_OK if the operation was successful.
      Throws:
      MessageException - if message processing fails with a fatal error.

    • releaseStateReference

      public void releaseStateReference(int messageProcessingModel, PduHandle pduHandle)
      Description copied from interface: MessageDispatcher
      Release any state references associated with the supplied PduHandle in the specified message processing model.
      Specified by:
      releaseStateReference in interface MessageDispatcher
      Parameters:
      messageProcessingModel - a message processing model ID.
      pduHandle - the PduHandle that identifies a confirmed class message.
      See Also:

    • getTransport

      public TransportMapping getTransport(Address destAddress)
      Description copied from interface: MessageDispatcher
      Returns a transport mapping that can handle the supplied address.
      Specified by:
      getTransport in interface MessageDispatcher
      Parameters:
      destAddress - an Address instance.
      Returns:
      a TransportMapping instance that can be used to sent a SNMP message to destAddress or null if such a transport mapping does not exists.

    • processMessage

      public void processMessage(TransportMapping sourceTransport, Address incomingAddress, ByteBuffer wholeMessage, TransportStateReference tmStateReference)
      Description copied from interface: MessageDispatcher
      Process an incoming SNMP message. The message is processed and dispatched according to the message's content, the message processing models, and the command responder available to the dispatcher.
      Specified by:
      processMessage in interface MessageDispatcher
      Specified by:
      processMessage in interface TransportListener
      Parameters:
      sourceTransport - a TransportMapping instance denoting the transport that received the message and that will be used to send any responses to this message. The sourceTransport has to support the incomingAddress's implementation class.
      incomingAddress - the Address from which the message has been received.
      wholeMessage - an ByteBuffer containing the received SNMP message.
      tmStateReference - the transport model state reference as defined by RFC 5590.