desmoj.core.advancedModellingFeatures

Class Stock

java.lang.Object

desmoj.core.simulator.NamedObject

desmoj.core.simulator.ModelComponent

desmoj.core.simulator.Reportable

desmoj.core.simulator.QueueBased

desmoj.core.advancedModellingFeatures.Stock

All Implemented Interfaces:

Subject<QueueBased,QueueBased.QueueAction>

Direct Known Subclasses:

StockAnimation

public class Stock
extends QueueBased

Stock is the place where a certain kind of product can be stored by producers and retrieved by consumers. There is no difference between the units of one kind of product, the units are indistinguishable. Producers are producing products and store them using store() in the Stock. Consumers make the Stock retrieve() the products to use them up. A Stock is also providing a process synchronization between producers and consumers. If no or not enough units of a product are available for the consumers, they have to wait in a queue until new units are delivered by a producer. The Stock has a certain capacity. If the Stock is filled to it's capacity producers have to wait in a queue until consumers are arriving and taking units out of the Stock. Then the producers can fill up the freed space. This is the major difference to the Bin. The first sort criterion of the queues is highest queueing priorities first (i.e. not using scheduling priorities - note that this is a somewhat arbitrary choice, as the Stock combines queueing and scheduling features). The second criterion, if a tie-breaker is needed, is the queueing discipline of the underlying queues, e.g. FIFO. The capacity limits can be determined by the user. Stock is derived from QueueBased, which provides all the statistical functionality for the consumer queue. The producer queue is managed by an internal ProcessQueue.

Version:

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

Author:

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:

QueueBased, Bin

Nested Class Summary

Nested classes/interfaces inherited from class desmoj.core.simulator.QueueBased

QueueBased.QueueAction

Field Summary

Fields inherited from class desmoj.core.simulator.QueueBased

FIFO, LIFO, RANDOM, UNDEFINED

Constructor Summary

Constructors

Constructor and Description
Stock(Model owner, java.lang.String name, int prodSortOrder, int prodQCapacity, int consSortOrder, int consQCapacity, long initialUnits, long capacity, boolean showInReport, boolean showInTrace) Constructor for a Stock with a certain capacity and a certain number of initial units of a product in it.
Stock(Model owner, java.lang.String name, long initialUnits, long capacity, boolean showInReport, boolean showInTrace) Constructor for a Stock with a certain capacity and a certain number of initial units of a product in it.

Method Summary

Modifier and Type	Method and Description
void	addPropertyChangeListener(java.beans.PropertyChangeListener listener) The addPropertyChangeListener method was generated to support the propertyChange field.
void	addPropertyChangeListener(java.lang.String propertyName, java.beans.PropertyChangeListener listener) The addPropertyChangeListener method was generated to support the propertyChange field.
double	avgAvail() Returning the average number of units available in the Stock over the time since the last reset of the Stock.
Reporter	createDefaultReporter() Returns a Reporter to produce a report about this Stock.
void	firePropertyChange(java.beans.PropertyChangeEvent evt) The firePropertyChange method was generated to support the propertyChange field.
void	firePropertyChange(java.lang.String propertyName, boolean oldValue, boolean newValue) The firePropertyChange method was generated to support the propertyChange field.
void	firePropertyChange(java.lang.String propertyName, int oldValue, int newValue) The firePropertyChange method was generated to support the propertyChange field.
void	firePropertyChange(java.lang.String propertyName, java.lang.Object oldValue, java.lang.Object newValue) The firePropertyChange method was generated to support the propertyChange field.
long	getAvail() Gets the available number of products in the Stock at the moment.
long	getCapacity() Gets the capacity property (long) value of this Stock, that is the number of units this stock can hold at max.
java.lang.String	getConsQueueStrategy() Returns the implemented queueing discipline of the underlying consumer queue as a String, so it can be displayed in the report.
long	getConsRefused() Returns the number of consumers that were refused to be enqueued because the queue for consumers was full.
long	getConsumers() Gets the consumers property (long) value.
long	getInitial() Gets the initial number of products the Stock starts with.
long	getMaximum() Gets the maximum number of products in the Stock.
long	getMinimum() Gets the minimum number of units in the Stock so far (since the last reset).
boolean	getPassByConsumers() Returns whether entities can pass by other entities which are enqueued before them in the queue.
boolean	getPassByProducers() Returns whether entities can pass by other entities which are enqueued before them in the queue.
java.lang.String	getProdQueueStrategy() Returns the implemented queueing discipline of the underlying queue for producers as a String, so it can be displayed in the report.
long	getProdRefused() Returns the number of producers that were refused to be enqueued because the queue for producers was full.
ProcessQueue<SimProcess>	getProducerQueue() Returns the queue where the producers are waiting to deliver their units.
long	getProducers() Gets the producers property (long) value.
long	getRefused() Gets the refused property (long) value.
java.lang.String	getWhere() Gets the where property (String) value denoting the method, where something has gone wrong.
boolean	hasListeners(java.lang.String propertyName) The hasListeners method was generated to support the propertyChange field.
void	removePropertyChangeListener(java.beans.PropertyChangeListener listener) The removePropertyChangeListener method was generated to support the propertyChange field.
void	removePropertyChangeListener(java.lang.String propertyName, java.beans.PropertyChangeListener listener) The removePropertyChangeListener method was generated to support the propertyChange field.
void	reset() Resets all statistical counters of this Stock to their default values.
boolean	retrieve(long n) Method for consumers to make the Stock retrieve a number of n units.
void	setPassByConsumers(boolean newPassBy) Sets the flag passBy to a new value.
void	setPassByProducers(boolean newPassBy) Sets the flag passBy to a new value.
boolean	store(long n) Method for producers to make the Stock store a number of n units.

Methods inherited from class desmoj.core.simulator.QueueBased

addObserver, averageLength, averageWaitTime, deleteObserver, getQueueLimit, length, maxLength, maxLengthAt, maxWaitTime, maxWaitTimeAt, minLength, minLengthAt, notifyObservers, setQueueImpWarning, stdDevLength, stdDevWaitTime, zeroWaits

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

Constructor Detail

Stock

public Stock(Model owner,
             java.lang.String name,
             int prodSortOrder,
             int prodQCapacity,
             int consSortOrder,
             int consQCapacity,
             long initialUnits,
             long capacity,
             boolean showInReport,
             boolean showInTrace)

Constructor for a Stock with a certain capacity and a certain number of initial units of a product in it. Waiting producer and consumer processes are sorted (and thus activated) according to their queueing priorities (highest first) and (if equal) by a queuing discipline as defined by QueueBased, e.g. QueueBased.FIFO or QueueBased.LIFO. The capacities of the underlying queues for waiting processes can be chosen, too.

Parameters:

owner - desmoj.Model : The model this Stock is associated to.

name - java.lang.String : The Stock's name, should indicate the kind of product stored in this Stock.

prodSortOrder - int : determines the sort order of the underlying queue implementation for the producers. Choose a constant from QueueBased like QueueBased.FIFO or QueueBased.LIFO or ...

prodQCapacity - int : The capacity of the producers queue, that is how many processes can be enqueued. Zero (0) means unlimited capacity.

consSortOrder - int : determines the sort order of the underlying queue implementation for the consumers. Choose a constant from QueueBased like QueueBased.FIFO or QueueBased.LIFO or ...

consQCapacity - int : The capacity of the consumers queue, that is how many processes can be enqueued. Zero (0) means unlimited capacity.

initialUnits - long : The units of a product the Stock starts with. Must be positive!

capacity - long : The maximum capacity of products this Stock can hold.

showInReport - boolean : Flag, if this Stock should produce a report or not.

showInTrace - boolean : Flag for trace to produce trace messages.

Stock

public Stock(Model owner,
             java.lang.String name,
             long initialUnits,
             long capacity,
             boolean showInReport,
             boolean showInTrace)

Constructor for a Stock with a certain capacity and a certain number of initial units of a product in it. Waiting producer and consumer processes are sorted (and thus activated) according to their queueing priorities (highest first) and (if equal) by FIFO. The capacities of the underlying queues for waiting processes are unlimited.

Parameters:

owner - desmoj.Model : The model this Stock is associated to.

name - java.lang.String : The Stock's name, should indicate the kind of product stored in this Stock.

initialUnits - long : The units of a product the Stock starts with. Must be positive!

capacity - long : The maximum capacity of products this Stock can hold.

showInReport - boolean : Flag, if this Stock should produce a report or not.

showInTrace - boolean : Flag for trace to produce trace messages.

Method Detail

addPropertyChangeListener

public void addPropertyChangeListener(java.beans.PropertyChangeListener listener)

The addPropertyChangeListener method was generated to support the propertyChange field.

addPropertyChangeListener

public void addPropertyChangeListener(java.lang.String propertyName,
                                      java.beans.PropertyChangeListener listener)

The addPropertyChangeListener method was generated to support the propertyChange field.

avgAvail

public double avgAvail()

Returning the average number of units available in the Stock over the time since the last reset of the Stock.

Returns:

double : The average number of units available in the Stock over the time since the last reset of the Stock.

createDefaultReporter

public Reporter createDefaultReporter()

Returns a Reporter to produce a report about this Stock.

Returns:

desmoj.report.Reporter : The Reporter reporting about the statistics of the two queues (producer and consumer) of this Stock.

firePropertyChange

public void firePropertyChange(java.beans.PropertyChangeEvent evt)

The firePropertyChange method was generated to support the propertyChange field.

firePropertyChange

public void firePropertyChange(java.lang.String propertyName,
                               int oldValue,
                               int newValue)

The firePropertyChange method was generated to support the propertyChange field.

firePropertyChange

public void firePropertyChange(java.lang.String propertyName,
                               java.lang.Object oldValue,
                               java.lang.Object newValue)

The firePropertyChange method was generated to support the propertyChange field.

firePropertyChange

public void firePropertyChange(java.lang.String propertyName,
                               boolean oldValue,
                               boolean newValue)

The firePropertyChange method was generated to support the propertyChange field.

getAvail

public long getAvail()

Gets the available number of products in the Stock at the moment.

Returns:

long : The available number of products in the Stock at the moment.

getCapacity

public long getCapacity()

Gets the capacity property (long) value of this Stock, that is the number of units this stock can hold at max.

Returns:

long : The capacity property value, that is the number of units this stock can hold at max.

getConsQueueStrategy

public java.lang.String getConsQueueStrategy()

Returns the implemented queueing discipline of the underlying consumer queue as a String, so it can be displayed in the report.

Returns:

String : The String indicating the queueing discipline.

getConsRefused

public long getConsRefused()

Returns the number of consumers that were refused to be enqueued because the queue for consumers was full.

Returns:

long : The number of consumers that were refused to be enqueued because the queue for consumers was full.

getConsumers

public long getConsumers()

Gets the consumers property (long) value.

Returns:

The consumers property value.

getInitial

public long getInitial()

Gets the initial number of products the Stock starts with.

Returns:

long : The initial number of products the Stock starts with.

getMaximum

public long getMaximum()

Gets the maximum number of products in the Stock.

Returns:

long : The maximum number of products in the Stock.

getMinimum

public long getMinimum()

Gets the minimum number of units in the Stock so far (since the last reset).

Returns:

long : The minimum number of units in the Stock since the last reset.

getPassByConsumers

public boolean getPassByConsumers()

Returns whether entities can pass by other entities which are enqueued before them in the queue.

Returns:

boolean : Indicates whether entities can pass by other entities which are enqueued before them in the queue.

getPassByProducers

public boolean getPassByProducers()

Returns whether entities can pass by other entities which are enqueued before them in the queue.

Returns:

boolean : Indicates whether entities can pass by other entities which are enqueued before them in the queue.

getProdQueueStrategy

public java.lang.String getProdQueueStrategy()

Returns the implemented queueing discipline of the underlying queue for producers as a String, so it can be displayed in the report.

Returns:

String : The String indicating the queueing discipline.

getProdRefused

public long getProdRefused()

Returns the number of producers that were refused to be enqueued because the queue for producers was full.

Returns:

long : The number of producers that were refused to be enqueued because the queue for producers was full.

getProducerQueue

public ProcessQueue<SimProcess> getProducerQueue()

Returns the queue where the producers are waiting to deliver their units.

Returns:

desmoj.ProcessQueue : the queue where the producers are waiting to deliver their units.

getProducers

public long getProducers()

Gets the producers property (long) value.

Returns:

The producers property value.

getRefused

public long getRefused()

Gets the refused property (long) value.

Returns:

The refused property value.

getWhere

public java.lang.String getWhere()

Gets the where property (String) value denoting the method, where something has gone wrong.

Returns:

java.lang.String : The where property value denoting the method, where something has gone wrong.

hasListeners

public boolean hasListeners(java.lang.String propertyName)

The hasListeners method was generated to support the propertyChange field.

removePropertyChangeListener

public void removePropertyChangeListener(java.beans.PropertyChangeListener listener)

The removePropertyChangeListener method was generated to support the propertyChange field.

removePropertyChangeListener

public void removePropertyChangeListener(java.lang.String propertyName,
                                         java.beans.PropertyChangeListener listener)

The removePropertyChangeListener method was generated to support the propertyChange field.

reset

public void reset()

Resets all statistical counters of this Stock to their default values. Both, producer queue and consumer queue are reset. The number of available units at this moment and the consumer and producer processes waiting in their queues remain unchanged. The maximum length of the queues are set to the current number of enqueued processes.

Overrides:

reset in class QueueBased

retrieve

public boolean retrieve(long n)
                 throws SuspendExecution

Method for consumers to make the Stock retrieve a number of n units. When there are not enough units available or another consumer is first in the queue to be served (and it is not possible to pass by), the current consumer process will be blocked and inserted in the waiting-queue (for consumers). The order of retrieving (and, thus, process re-activation) depends on the order of the internal queue, which is based on the consumer processes' queueing priorities and (if queueing priorities are equal, requiring a tie-breaker) by FIFO or a different discipline as defined in the constructor.

Parameters:

n - long : The number of units the Stock is retrieving for the consumer; must be positive.

Returns:

boolean : Is true if the specified number of units can been retrieved successfully, false otherwise (i.e. capacity limit of the queue is reached).

Throws:

SuspendExecution

setPassByConsumers

public void setPassByConsumers(boolean newPassBy)

Sets the flag passBy to a new value. PassBy is indicating whether entities can pass by other entities which are enqueued before them in the queue.

Parameters:

newPassBy - boolean : The new value of passBy. Set it to true if you want entities to pass by other entities which are enqueued before them in the queue. Set it to false if you don't want entities to overtake other entities in the queue.

setPassByProducers

public void setPassByProducers(boolean newPassBy)

Sets the flag passBy to a new value. PassBy is indicating whether entities can pass by other entities which are enqueued before them in the queue.

Parameters:

newPassBy - boolean : The new value of passBy. Set it to true if you want entities to pass by other entities which are enqueued before them in the queue. Set it to false if you don't want entities to overtake other entities in the queue.

store

public boolean store(long n)
              throws SuspendExecution

Method for producers to make the Stock store a number of n units. When the capacity of the stock can not hold the additional incoming units or another producer is already waiting at first position in the queue (and it is not possible to pass by), the current producer process will be blocked and inserted in the queue (for producers). The order of storing (and, thus, process re-activation) depends on the order of the internal queue, which is based on the producers processes' queueing priorities and (if queueing priorities are equal, requiring a tie-breaker) by FIFO or a different discipline as defined in the constructor.

Parameters:

n - long : The number of units the Stock is receiving from the producer to store. n must be positive.

Returns:

boolean : Is true if the specified number of units can been stored successfully, false otherwise (i.e. capacity limit of the queue is reached).

Throws:

SuspendExecution