QueueBased (DESMO-J 2.5.1c API)

java.lang.Object
- desmoj.core.simulator.NamedObject
- - desmoj.core.simulator.ModelComponent
  - - desmoj.core.simulator.Reportable
    - - desmoj.core.simulator.QueueBased

All Implemented Interfaces:

Subject<QueueBased,QueueBased.QueueAction>

Direct Known Subclasses:

Berth, Bin, CondQueue, CranesSystem, Entrepot, ProcessQueue, Queue, Res, Stock, TransporterSystem, WaitQueue, WorkStation
```
public abstract class QueueBased
extends Reportable
implements Subject<QueueBased,QueueBased.QueueAction>
```
Provides the typical statistics common to all ModelComponents based on Queues. It is set abstract to prevent users to use it straight without deriving a class first because it only provides the functionality for statistical data extraction, not the functionality for actually queueing Entities. The statistical values provided are the queue's length and its elements' waiting times with minimum, maximum, mean and standard deviation for each. This class should be used when any type of ModelComponent using Queues is created. In combination with class QueueList an automatic insert/remove mechanism including search functionality with condition checking can be set up within a few lines of code. It also provides full automatic statistical data about the Queue used.

Version:

DESMO-J, Ver. 2.5.1c copyright (c) 2015

Author:

Tim Lechler, modified by Soenke Claassen Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

See Also:

QueueList

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class QueueBased.QueueAction
Enum to representing the actions of adding and removing an item to/from the queue.

Nested Classes
Modifier and Type	Class and Description
`static class`	`QueueBased.QueueAction` Enum to representing the actions of adding and removing an item to/from the queue.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`FIFO` Defining a constant for the FIFO (First In First Out) service discipline of the underlying queue: An Entity inserted into the queue is removed after all entities already enqueued with the same priority.
`static int`	`LIFO` Defining a constant for the LIFO (Last In First Out) service discipline of the underlying queue: An Entity inserted into the queue is removed before all entities already enqueued with the same priority.
`static int`	`RANDOM` Defining a constant for the random service discipline of the underlying queue: An Entity inserted into the queue may be removed before or after any other Entity with the same priority.
`static double`	`UNDEFINED` Represents the value returned if for a given statistics no valid value can be returned.

Constructor Summary

Constructors
Constructor and Description
`QueueBased(Model owner, java.lang.String name, boolean showInReport, boolean showInTrace)` Creates a QueueBased object and initializes all statistical counters.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addObserver(Observer<QueueBased,QueueBased.QueueAction> observer)` This method adds an observer to the subject
`double`	`averageLength()` Returns the average length of the underlying queue since the last reset.
`TimeSpan`	`averageWaitTime()` Returns the average waiting time of all objects who have exited the queue.
`void`	`deleteObserver(Observer<QueueBased,QueueBased.QueueAction> observer)` This method deletes an observer from the subject
`int`	`getQueueLimit()` Returns the maximum possible number of entities in the underlying queue.
`int`	`length()` Returns the current length of the underlying queue.
`int`	`maxLength()` Returns the maximum length of the underlying queue since the last reset.
`TimeInstant`	`maxLengthAt()` Returns the point of simulation time with the maximum number of objects waiting inside the underlying queue.
`TimeSpan`	`maxWaitTime()` Returns the maximum duration in simulation time that an object has spent waiting inside the underlying queue.
`TimeInstant`	`maxWaitTimeAt()` Returns the point of simulation time when the object with the maximum waiting time exited the underlying queue.
`int`	`minLength()` Returns the minimumn length of the underlying queue since the last reset.
`TimeInstant`	`minLengthAt()` Returns the point of simulation time with the minimum number of objects waiting inside the underlying queue.
`void`	`notifyObservers(QueueBased subject, QueueBased.QueueAction eventObject)` This method is used to notify the registerd observers
`void`	`reset()` Resets all statistical counters to their default values.
`void`	`setQueueImpWarning(boolean warnFlag)` Method switches on warnings issued from the underlying queue implementation if parameter given is `true`.
`double`	`stdDevLength()` Returns the standard deviation of the queue's length.
`TimeSpan`	`stdDevWaitTime()` Returns the standard deviation of the queue's objects waiting times.
`long`	`zeroWaits()` Returns the number of objects that have passed through the queue without spending time waiting.

Methods inherited from class desmoj.core.simulator.Reportable
getCorrespondingSchedulable, getDescription, getObservations, getReporter, incrementObservations, incrementObservations, reportIsOn, reportOff, reportOn, resetAt, setCorrespondingSchedulable, setDescription, setReporter

Methods inherited from class desmoj.core.simulator.ModelComponent
current, currentEntity, currentEntityAll, currentEvent, currentModel, currentSimProcess, debugIsOn, debugOff, debugOn, getModel, isExperimentCompatible, isModelCompatible, presentTime, sendDebugNote, sendMessage, sendTraceNote, sendWarning, skipTraceNote, skipTraceNote, traceIsOn, traceOff, traceOn

Methods inherited from class desmoj.core.simulator.NamedObject
getName, getQuotedName, toString

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - UNDEFINED
```
public static final double UNDEFINED
```
    Represents the value returned if for a given statistics no valid value can be returned.
    
    See Also:
    
    Constant Field Values
  - FIFO
```
public static final int FIFO
```
    Defining a constant for the FIFO (First In First Out) service discipline of the underlying queue: An Entity inserted into the queue is removed after all entities already enqueued with the same priority.
    
    See Also:
    
    Constant Field Values
  - LIFO
```
public static final int LIFO
```
    Defining a constant for the LIFO (Last In First Out) service discipline of the underlying queue: An Entity inserted into the queue is removed before all entities already enqueued with the same priority.
    
    See Also:
    
    Constant Field Values
  - RANDOM
```
public static final int RANDOM
```
    Defining a constant for the random service discipline of the underlying queue: An Entity inserted into the queue may be removed before or after any other Entity with the same priority.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - QueueBased
```
public QueueBased(Model owner,
                  java.lang.String name,
                  boolean showInReport,
                  boolean showInTrace)
```
    Creates a QueueBased object and initializes all statistical counters. If this standard constructor is used a queue with Fifo sort order and no limited capacity will be created.
    
    Parameters:
    
    owner - desmoj.Model : The model it belongs to
    
    name - java.lang.String : The name for this QueueBased object
    
    showInReport - boolean : Flag if values are shown in report
    
    showInTrace - boolean : Flag if QueueBased writes trace messages
- Method Detail
  - addObserver
```
public void addObserver(Observer<QueueBased,QueueBased.QueueAction> observer)
```
    Description copied from interface: Subject
    
    This method adds an observer to the subject
    
    Specified by:
    
    addObserver in interface Subject<QueueBased,QueueBased.QueueAction>
    
    Parameters:
    
    observer - the observer which should be added to the subject
  - averageLength
```
public double averageLength()
```
    Returns the average length of the underlying queue since the last reset. Current length of that queue will be returned, if the time span since the last reset is smaller than the smallest distinguishable timespan epsilon.
    
    Returns:
    
    double : The average queue length since last reset or current length of queue if no distinguishable periode of time has passed
  - averageWaitTime
```
public TimeSpan averageWaitTime()
```
    Returns the average waiting time of all objects who have exited the queue. Value is valid for the time span since the last reset. Returns 0 (zero) if no objects have exited the queue after the last reset.
    
    Returns:
    
    TimeSpan : Average waiting time of all objects since last reset or 0 if no objects have exited the queue
  - deleteObserver
```
public void deleteObserver(Observer<QueueBased,QueueBased.QueueAction> observer)
```
    Description copied from interface: Subject
    
    This method deletes an observer from the subject
    
    Specified by:
    
    deleteObserver in interface Subject<QueueBased,QueueBased.QueueAction>
    
    Parameters:
    
    observer - the observer which should be deleted
  - getQueueLimit
```
public int getQueueLimit()
```
    Returns the maximum possible number of entities in the underlying queue.
    
    Returns:
    
    int : the maximum number of entities in the queue.
  - length
```
public int length()
```
    Returns the current length of the underlying queue.
    
    Returns:
    
    int : The current queue length, zero if empty.
  - maxLength
```
public int maxLength()
```
    Returns the maximum length of the underlying queue since the last reset.
    
    Returns:
    
    int : The maximum queue length since last reset
  - maxLengthAt
```
public TimeInstant maxLengthAt()
```
    Returns the point of simulation time with the maximum number of objects waiting inside the underlying queue. The value is valid for the period since the last reset.
    
    Returns:
    
    desmoj.TimeInstant : Point of time with maximum queue length since last reset
  - maxWaitTime
```
public TimeSpan maxWaitTime()
```
    Returns the maximum duration in simulation time that an object has spent waiting inside the underlying queue. The value is valid for the period since the last reset.
    
    Returns:
    
    desmoj.TimeSpan : Longest waiting time of an object in the queue since last reset
  - maxWaitTimeAt
```
public TimeInstant maxWaitTimeAt()
```
    Returns the point of simulation time when the object with the maximum waiting time exited the underlying queue. The value is valid for the period since the last reset.
    
    Returns:
    
    desmoj.TimeInstant : The point of simulation time when the object with the maximum waiting time exited the queue
  - minLength
```
public int minLength()
```
    Returns the minimumn length of the underlying queue since the last reset.
    
    Returns:
    
    int : The minimum queue length since last reset
  - minLengthAt
```
public TimeInstant minLengthAt()
```
    Returns the point of simulation time with the minimum number of objects waiting inside the underlying queue. The value is valid for the period since the last reset.
    
    Returns:
    
    desmoj.TimeInstant : Point of time with minimum queue length since last reset
  - notifyObservers
```
public void notifyObservers(QueueBased subject,
                            QueueBased.QueueAction eventObject)
```
    Description copied from interface: Subject
    
    This method is used to notify the registerd observers
    
    Specified by:
    
    notifyObservers in interface Subject<QueueBased,QueueBased.QueueAction>
    
    Parameters:
    
    subject - reference to the actual subject
    
    eventObject - an eventtype to distinguish different notification types like itemAdded or itemRemoved
  - reset
```
public void reset()
```
    Resets all statistical counters to their default values. The mininum and maximum length of the queue are set to the current number of queued objects.
    
    Overrides:
    
    reset in class Reportable
  - setQueueImpWarning
```
public void setQueueImpWarning(boolean warnFlag)
```
    Method switches on warnings issued from the underlying queue implementation if parameter given is true. Warnings are suppressed if false is given. This method is used for internal debugging only.
    
    Parameters:
    
    warnFlag - boolean :true switches warnings on, false switches warnings off
  - stdDevLength
```
public double stdDevLength()
```
    Returns the standard deviation of the queue's length. Value is weighted over time.
    
    Returns:
    
    double : The standard deviation for the queue's length weighted over time
  - stdDevWaitTime
```
public TimeSpan stdDevWaitTime()
```
    Returns the standard deviation of the queue's objects waiting times.
    
    Returns:
    
    double : The standard deviation for the queue's objects waiting times
  - zeroWaits
```
public long zeroWaits()
```
    Returns the number of objects that have passed through the queue without spending time waiting.
    
    Returns:
    
    long : The number of elements who have passed the queue without waiting

Class QueueBased

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class desmoj.core.simulator.Reportable

Methods inherited from class desmoj.core.simulator.ModelComponent

Methods inherited from class desmoj.core.simulator.NamedObject

Methods inherited from class java.lang.Object

Field Detail

UNDEFINED

FIFO

LIFO

RANDOM

Constructor Detail

QueueBased

Method Detail

addObserver

averageLength

averageWaitTime

deleteObserver

getQueueLimit

length

maxLength

maxLengthAt

maxWaitTime

maxWaitTimeAt

minLength

minLengthAt

notifyObservers

reset

setQueueImpWarning

stdDevLength

stdDevWaitTime

zeroWaits