Package PamguardMVC

Class ThreadedObserver

java.lang.Object
PamguardMVC.ThreadedObserver
All Implemented Interfaces:
PamObserver
public class ThreadedObserver extends Object implements PamObserver
This is a decorator class for PamObservers which intercepts any data being sent to that observer and puts the data into a list which will then be re-read in a separate thread, rather than sending if for direct execution.

There is a bit of jiggledy piggledy to get the data history times right since they may need to be extended slightly to allow for data that are not yet used.

Author:
Doug Gillespie

  • Field Details

    • MODULEEXCEPTIONLINE

      public static String MODULEEXCEPTIONLINE

  • Constructor Details

    • ThreadedObserver

      public ThreadedObserver(PamObservable pamObservable, PamObserver singleThreadObserver)
      Make an intermediate observer of a PamObservable (i.e. datablock) which will queue the data for analysis in a different thread.
      Parameters:
      pamObservable -
      singleThreadObserver -

  • Method Details

    • getObserverObject

      public PamObserver getObserverObject()
      Specified by:
      getObserverObject in interface PamObserver
      Returns:
      the actual observer. In most cases concrete classes will just return 'this' in response. The exception is the Threaded observer, which will return the single thread observer.

    • getObserverName

      public String getObserverName()
      Specified by:
      getObserverName in interface PamObserver

    • getRequiredDataHistory

      public long getRequiredDataHistory(PamObservable o, Object arg)
      Specified by:
      getRequiredDataHistory in interface PamObserver
      Parameters:
      arg - optional argument from PamObservable
      Returns:
      time in milliseconds required by data held in PamObservable

    • getInterThreadListSize

      public int getInterThreadListSize()
      Get the number of objects in the queue.
      Returns:
      number of objests

    • noteNewSettings

      public void noteNewSettings()
      Specified by:
      noteNewSettings in interface PamObserver

    • terminateThread

      public void terminateThread()
      Terminate the threaded observer by setting the flag that causes the observing loop to drop out.

    • removeObservable

      public void removeObservable(PamObservable o)
      Description copied from interface: PamObserver
      called when an Observable (PamDataBlock) is removed from the system
      Specified by:
      removeObservable in interface PamObserver

    • setSampleRate

      public void setSampleRate(float sampleRate, boolean notify)
      Description copied from interface: PamObserver
      New sample rate
      Specified by:
      setSampleRate in interface PamObserver
      Parameters:
      sampleRate -
      notify - Notify other PamObservers and PamObservables in the chain.

    • masterClockUpdate

      public void masterClockUpdate(long milliSeconds, long sampleNumber)
      Specified by:
      masterClockUpdate in interface PamObserver

    • addData

      public void addData(PamObservable o, PamDataUnit newDataUnit)
      Description copied from interface: PamObserver
      Informs the PamObserver that new data have been added to the Observable class
      Specified by:
      addData in interface PamObserver

    • updateData

      public void updateData(PamObservable observable, PamDataUnit pamDataUnit)
      Description copied from interface: PamObserver
      Informs the PamObserver that existing data have been updated
      Specified by:
      updateData in interface PamObserver

    • receiveSourceNotification

      public void receiveSourceNotification(int type, Object object)
      Description copied from interface: PamObserver
      Receive a notification from the data source - typically a change in DAQ status. See the constants listed in AcquisitionProcess for potential change types.
      Specified by:
      receiveSourceNotification in interface PamObserver
      Parameters:
      type - the type of change
      object - generic object added here so that we can include anything in the future

    • getQueueLimits

      public long[] getQueueLimits()
      Get the millisecond times of the first and last items in the queue.
      Returns:
      first and last times, or null if the queue is empty.

    • waitForQueueToBeReady

      protected void waitForQueueToBeReady(ObservedObject theObject)
      Check to see if the queue is ready to accept a new Object. If the queue is currently full, then wait inside this method until the queue has emptied out.

      Note that the object will be added to the queue when this method returns, so all delays must be done in here.

      Parameters:
      theObject - The Object waiting to be added to the queue

    • waitToEmpty

      public long waitToEmpty(long timeout)
      Wait for the queue to be empty. This REALLY must not get called from the NewObserverThread or you'll get a thread lock, so don't
      Parameters:
      timeout - maximum time to wait for thread.
      Returns:
      +ve integer number of millis if it ended normally, negative for an error code. -1 for a timeout or -2 for it calling within it's own observer thread.

    • sleepWriter

      public void sleepWriter()
      Sleep the writing thread by jittersleep (default 10ms)

    • isEmptyRead

      public boolean isEmptyRead()
      Returns:

    • getMaxJitter

      public long getMaxJitter()
      This is the maximum amount of data in milliseconds that can sit in the queue. Normally it's about a second.
      Returns:
      the maxJitter

    • setMaxJitter

      public void setMaxJitter(long maxJitter)
      Parameters:
      maxJitter - the maxJitter to set

    • clearEverything

      public void clearEverything()

    • dumpBufferStatus

      public void dumpBufferStatus(String message, boolean sayEmpties)