ikr.simlib.events.calendar

Class Calendar

java.lang.Object

ikr.simlib.events.calendar.Calendar

Direct Known Subclasses:

OrderedTreeSetCalendar, SimpleOrderedCalendar, StdOrderedCalendar

public abstract class Calendar
extends java.lang.Object

Calendars are special event handlers derived from the abstract base class Calendar. The classes store references to callback methods ( CalendarCallback) and associated points in time (PointInTime) when the callbacks are to be executed.

In addition to the event time, a priority of the event can be provided. These priorities come into effect if events are scheduled to be executed at the same time. In that case, they are processed in the order of decreasing priority, i.e., the event with the highest priority is processed first.

When posting an event, the calendar returns an instance of EventToken , which can be used to query the state of the event and to cancel the event.

With the method processNextEvent() the events can be executed in the scheduled order. Calendars are used by models, see Model for more details.

Event priorities are integer numbers and may be negative. The default priority is 0. The processing order of events with the same time and the same priority is not defined and may vary in-between calendar implementations.

Field Summary

Fields

Modifier and Type	Field and Description
protected static Calendar	CALENDAR reference to calendar
protected int	concurrentEvents counter to count the number of events with exact same time stamp
protected UnweightedSampleCollector<java.lang.Double>	eventsWithSameTimeStat
protected PointInTime	systemTime the current simulation time

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Calendar()

Method Summary

Methods

Modifier and Type	Method and Description
abstract void	cancelAllEvents() Cancel all events which are currently posted.
static Calendar	getInstance() calendar access method
PointInTime	getSystemTime() Returns the current simulation time
static boolean	hasInstance()
abstract boolean	isEventAvailable() Return true if there are events in the calendar.
abstract PointInTime	peekNextEventTime() Returns the time stamp of the next event in the calendar without removing it.
EventToken	postEvent(CalendarCallback onExecute, CalendarCallback onCancel, PointInTime eventTime) As postEvent(CalendarCallback, CalendarCallback, PointInTime, int), but sets the eventPriority to 0.
abstract EventToken	postEvent(CalendarCallback onExecute, CalendarCallback onCancel, PointInTime eventTime, int eventPriority) Creates a new entry in the calendar.
abstract void	processNextEvent() Gets the next event on the schedule and calls its onExecute method.
static void	setInstance(Calendar calendar)
void	setSameTimeEventStatistic(UnweightedSampleCollector<java.lang.Double> collector) If set, the number of events with the exact same time stamp are collected in the given UnweightedSampleCollector.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

CALENDAR

protected static Calendar CALENDAR

reference to calendar

systemTime

protected PointInTime systemTime

the current simulation time

eventsWithSameTimeStat

protected UnweightedSampleCollector<java.lang.Double> eventsWithSameTimeStat

concurrentEvents

protected int concurrentEvents

counter to count the number of events with exact same time stamp

Constructor Detail

Calendar

protected Calendar()

Method Detail

getInstance

public static Calendar getInstance()

calendar access method

setInstance

public static void setInstance(Calendar calendar)

hasInstance

public static boolean hasInstance()

postEvent

public abstract EventToken postEvent(CalendarCallback onExecute,
                   CalendarCallback onCancel,
                   PointInTime eventTime,
                   int eventPriority)

Creates a new entry in the calendar.

Parameters:

onExecute - Function to call when the event is processed. May be null.

onCancel - Function to call when the event is cancelled. May be null.

eventTime - Time at which to call the onExecute function. Must be later or equal than the current system time returned by getSystemTime().

eventPriority - Key used for sorting to break ties for two entries with the same eventTime.

Returns:

An object which allows event-specific interaction with the calendar.

postEvent

public EventToken postEvent(CalendarCallback onExecute,
                   CalendarCallback onCancel,
                   PointInTime eventTime)

As postEvent(CalendarCallback, CalendarCallback, PointInTime, int), but sets the eventPriority to 0.

cancelAllEvents

public abstract void cancelAllEvents()

Cancel all events which are currently posted.

isEventAvailable

public abstract boolean isEventAvailable()

Return true if there are events in the calendar.

peekNextEventTime

public abstract PointInTime peekNextEventTime()

Returns the time stamp of the next event in the calendar without removing it.

Returns:

preview onto the time stamp of the next event in the calendar

getSystemTime

public PointInTime getSystemTime()

Returns the current simulation time

Returns:

the simulation time

processNextEvent

public abstract void processNextEvent()

Gets the next event on the schedule and calls its onExecute method.

setSameTimeEventStatistic

public void setSameTimeEventStatistic(UnweightedSampleCollector<java.lang.Double> collector)

If set, the number of events with the exact same time stamp are collected in the given UnweightedSampleCollector. The number of events with same time stamp