Class LifoTaskQueue

All Implemented Interfaces:
QueueStatus, NamedObjectOps

public class LifoTaskQueue extends DelayTaskQueue
LIFO (Last In First Out) delay queue.
  • Constructor Details

    • LifoTaskQueue

      public LifoTaskQueue(Simulation sim, boolean intern)
      Constructor.
      Parameters:
      sim - the simulation
      intern - true if the queue should be interned, false otherwise.
    • LifoTaskQueue

      public LifoTaskQueue(Simulation sim, String name, boolean intern) throws IllegalArgumentException
      Constructor with name.
      Parameters:
      sim - the simulation
      name - the name of the queue
      intern - true if the queue should be interned, false otherwise.
      Throws:
      IllegalArgumentException - typically means a name is already in use
  • Method Details

    • 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<DelayTaskQueue.Parameter>
      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<DelayTaskQueue.Parameter>
      Returns:
      true if preempt mode is supported; false otherwise
      See Also:
    • offerToQueue

      protected boolean offerToQueue(TaskQueueSimEvent<DelayTaskQueue.Parameter> event, TaskQueueSimEvent<DelayTaskQueue.Parameter> scheduled)
      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<DelayTaskQueue.Parameter>
      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

      protected TaskQueueSimEvent<DelayTaskQueue.Parameter> 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<DelayTaskQueue.Parameter>
      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