Class PriorityTaskQueue

All Implemented Interfaces:
QueueStatus, NamedObjectOps

public class PriorityTaskQueue extends TaskQueue<PriorityTaskQueue.PriorityParam>
Priority task queue. Entries are taken off the queue according to a priority. For two entries with the same priority, FIFO order is used.
  • Constructor Details

    • PriorityTaskQueue

      public PriorityTaskQueue(Simulation sim, boolean intern)
      Constructor for unnamed priority task queues. If interned, a name will be automatically generated.
      Parameters:
      sim - the simulation
      intern - true of the queue should be interned in the simulation's name table; false otherwise
    • PriorityTaskQueue

      public PriorityTaskQueue(Simulation sim, String name, boolean intern) throws IllegalArgumentException
      Constructor for named priority task queues.
      Parameters:
      sim - the simulation
      name - the name for the queue
      intern - true of the queue should be interned in the simulation's name table; false otherwise
      Throws:
      IllegalArgumentException - typically means a name is already in use
  • Method Details

    • add

      public SimulationEvent add(Callable callable, int priority, long interval)
      Add a Callable to the queue.
      Parameters:
      callable - the Callable to add
      priority - the priority for the Callable to be added
      interval - the interval between when callable is scheduled to be called and when it is actually called, representing the service time for this queue entry.
      Returns:
      the SimulationEvent created
    • add

      public SimulationEvent add(SimObjectCallable callable, int priority, long interval)
      Add a SimObjectCallable to the queue.
      Parameters:
      callable - the SimObjectCallable to add
      priority - the priority for the Callable to be added
      interval - the interval between when callable is scheduled to be called and when it is actually called, representing the service time for this queue entry.
      Returns:
      the SimulationEvent created
    • addCallScript

      public SimulationEvent addCallScript(String script, int priority, long interval)
      Add a script to execute to the queue. When the script reaches the head of the queue and is then processed, it will be evaluated.
      Parameters:
      script - the script to add to the queue
      priority - the priority for the Callable to be added
      interval - the interval between when callable is scheduled to be called and when it is actually called, representing the service time for this queue entry.
      Returns:
      the SimulationEvent created; null if the script cannot be queued
    • addCallObject

      public SimulationEvent addCallObject(Object scriptObject, int priority, long interval)
      Add a script object to execute to the queue. When the object reaches the head of the queue and is scheduled, it's call() method will be invoked.
      Parameters:
      scriptObject - the script object to add
      priority - the priority for the Callable to be added
      interval - the interval between when callable is scheduled to be called and when it is actually called, representing the service time for this queue entry.
      Returns:
      the SimulationEvent created
    • add

      public SimulationEvent add(Runnable runnable, int priority, long interval)
      Add a Runnable to the queue.
      Parameters:
      runnable - the Runnable to add to the queue
      priority - the priority for Runnable to be added
      interval - the interval between when runnable is scheduled to be started and when it is actually started, representing the service time for this queue entry.
      Returns:
      the SimulationEvent created
    • add

      public SimulationEvent add(SimObjectRunnable runnable, int priority, long interval)
      Add a SimObjectRunnable to the queue.
      Parameters:
      runnable - the SimObjectRunnable to add to the queue
      priority - the priority for Runnable to be added
      interval - the interval between when runnable is scheduled to be started and when it is actually started, representing the service time for this queue entry.
      Returns:
      the SimulationEvent created
    • addTaskScript

      public SimulationEvent addTaskScript(String script, int priority, long interval)
      Add a script to run in a task to the queue.
      Parameters:
      script - the script to add to the queue
      priority - the priority for Runnable to be added
      interval - the interval between when runnable is scheduled to be started and when it is actually started, representing the service time for this queue entry.
      Returns:
      the SimulationEvent created; null if the script could not be queued
    • addTaskObject

      public SimulationEvent addTaskObject(Object scriptObject, int priority, long interval)
      Add a script object to run in a task to the queue.
      Parameters:
      scriptObject - the object to add to the queue
      priority - the priority for Runnable to be added
      interval - the interval between when runnable is scheduled to be started and when it is actually started, representing the service time for this queue entry.
      Returns:
      the SimulationEvent created; null if the object could not be queued
    • addCurrentTask

      public void addCurrentTask(int priority, long interval) throws IllegalStateException
      Add the currently running task thread to a priority queue.
      Parameters:
      priority - the priority for task to be added
      interval - the interval between when runnable is scheduled to be started and when it is actually started, representing the service time for this queue entry.
      Throws:
      IllegalStateException
    • addCurrentTask

      public void addCurrentTask(int priority, long interval, SimEventCallable callable) throws IllegalStateException
      Add the currently running task thread to a priority queue allowing for cancellation.
      Parameters:
      priority - the priority for task thread to be added
      interval - the interval between when runnable is scheduled to be started and when it is actually started, representing the service time for this queue entry.
      callable - this argument's call method will be run when the event is scheduled and will be passed a simulation event (e.g., to store the event to allow the event to be canceled)
      Throws:
      IllegalStateException
    • addCurrentTaskObject

      public SimulationEvent addCurrentTaskObject(int priority, long interval) throws IllegalStateException
      Add the currently running task thread to a queue and return the SimulationEvent generated.
      Parameters:
      priority - the priority for task thread to be added
      interval - the interval between when runnable is scheduled to be started and when it is actually started, representing the service time for this queue entry.
      Returns:
      a simulation event on success; null on failure in which case the current thread will continue to run
      Throws:
      IllegalStateException
    • getInterval

      protected long getInterval(PriorityTaskQueue.PriorityParam parameter)
      Description copied from class: TaskQueue
      Find the interval used to schedule a queue entry based on entry's parameters or a default value.
      Specified by:
      getInterval in class TaskQueue<PriorityTaskQueue.PriorityParam>
      Parameters:
      parameter - the parameters for a queue entry
      Returns:
      the interval in units of simulation ticks
    • getSize

      protected int getSize()
      Description copied from class: TaskQueue
      Get the raw size of the queue. The size does not include the currently scheduled event. It does contain any events that were canceled but could not be removed.
      Specified by:
      getSize in class TaskQueue<PriorityTaskQueue.PriorityParam>
      Returns:
      the queue size
    • canPreempt

      public boolean canPreempt()
      Description copied from class: TaskQueue
      Determine if a a task queue supports preempt mode.
      Overrides:
      canPreempt in class TaskQueue<PriorityTaskQueue.PriorityParam>
      Returns:
      true if preempt mode is supported; false otherwise
      See Also:
    • offerToQueue

      Description copied from class: TaskQueue
      Put an event on the queue. This method should be implemented by subclasses, which should also provide a queue on which to store an event. Normally an event is just added to the end of the queue. For some cases (e.g., a LIFO queue), one may need to preempt a currently scheduled event. If preemption is necessary, the preempted event's time parameters will have to be adjusted and the new event will have to become the scheduled event. The latter operation is handled by replaceScheduledEvent. If replaceScheduledEvent is used, care must be taken if the queue insertion could fail (e.g., the case of a finite-sized queue). For modifying the event parameters (e.g., to allow for time already attributed to processing an event), the methods getOffQueueTime and getEventParameters may be useful.
      Specified by:
      offerToQueue in class TaskQueue<PriorityTaskQueue.PriorityParam>
      Parameters:
      event - the event
      scheduled - the event that is currently scheduled for processing; null if there is none or if preempt mode is turned off
      Returns:
      true if an event was successfully added to the queue; false otherwise
    • pollFromQueue

      Description copied from class: TaskQueue
      Take an event off the queue. This method should be implemented by subclasses, which should also provide a queue on which to store an event.
      Specified by:
      pollFromQueue in class TaskQueue<PriorityTaskQueue.PriorityParam>
      Returns:
      the event; null if the queue is empty
    • clone

      protected Object clone() throws CloneNotSupportedException
      Creates and returns a copy of this object. This method will throw the exception CloneNotSupportedException if the object is interned.
      Overrides:
      clone in class Object
      Throws:
      CloneNotSupportedException - a clone could not be created
      See Also:
    • isInterned

      public boolean isInterned()
      Determine if an object is interned in a object namer's tables.
      Specified by:
      isInterned in interface NamedObjectOps
      Returns:
      true if the object is interned; false if not
    • getObjectNamer

      protected Simulation getObjectNamer()
      Get the object namer for a named object.
      Returns:
      the object namer for this named object
    • getName

      public final String getName()
      Get an object's name.
      Specified by:
      getName in interface NamedObjectOps
      Returns:
      the name of the object
    • delete

      public final boolean delete()
      Delete an object. An object can only be deleted once. If this method returns true, the object (if interned) will have been removed from the object namer tables.

      The implementations provided by DefaultNamedObect and generated because of a @NamedObject annotation provide a protected method named onDelete. A subclass that overrides onDelete() must call the onDelete method of its superclass after it's onDelete method has been called and any cleanup actions performed. In some cases, this may happen at a later time (e.g., if a thread is used for some of the cleanup operations or if it is otherwise necessary to wait).

      Specified by:
      delete in interface NamedObjectOps
      Returns:
      true if the deletion request was accepted; false otherwise
    • isDeleted

      public final boolean isDeleted()
      Determine if an object has been deleted. An object is deleted if the method delete() has been called and returned true.
      Specified by:
      isDeleted in interface NamedObjectOps
      Returns:
      true if deleted; false otherwise
    • deletePending

      public final boolean deletePending()
      Determine if an object is being deleted. An deletion is pending if the method delete() has been called and returned true but the deletion has not been completed.
      Specified by:
      deletePending in interface NamedObjectOps
      Returns:
      true if deletion is pending; false otherwise