javax.realtime
Class RationalTime

java.lang.Object
  javax.realtime.HighResolutionTime
      javax.realtime.RelativeTime
          javax.realtime.RationalTime

All Implemented Interfaces:

Comparable

public class RationalTime

extends RelativeTime

An object that represents a time interval millis/1E3+nanos/1E9 seconds long that is divided into subintervals by some frequency. This is generally used in periodic events, threads, and feasibility analysis to specify periods where there is a basic period that must be adhered to strictly (the interval), but within that interval the periodic events aresupposed to happenfrequencytimes,asuniformly spaced as possible,butclock and scheduling jitter is moderately acceptable. If the value of any of the millisecond or nanosecond fields is negative the variable is set to negative value. Although logically this may represent time before the epoch, invalid results may occur if an instance of AbsoluteTime representing time before the epoch is given as a parameter to the a method.

Caution: This class is explicitly unsafe in multithreaded situations when it is being changed. No synchronization is done. It is assumed that users of this class who are mutating instances will be doing their own synchronization at a higher level.

Author:

Angelo Corsaro

Field Summary

protected int

frequency

Fields inherited from class javax.realtime.HighResolutionTime

millis, nanos

Constructor Summary

RationalTime(int frequency)
Construct a new Object of RationalTime Equivalent to new Rational-Time( 1000, 0, frequency)---essentially a cycles-per-second value.

RationalTime(int frequency, long millis, int nanos)
Construct a new Object of RationalTime.

RationalTime(int frequency, RelativeTime interval)
Construct a new Object of RationalTime from the given RelativeTime.

Method Summary

void	addInterarrivalTo(AbsoluteTime destination) Add thistime to an AbsoluteTime.
int	getFrequency() Gets the frequency associated with this.
RelativeTime	getInterarrivalTime() Gets the time duration between two consecutive ticks using frequency.
void	getInterarrivalTime(RelativeTime destination) Gets the time duration between two consecutive ticks using frequency.
void	set(long millis, int nanos) Change the indicated interval of this to the sum of the values of the arguments.
void	setFrequency(int frequency) Set the frequency of this.

Methods inherited from class javax.realtime.RelativeTime

absolute, absolute, add, add, add, add, decrement, increment, subtract, subtract, toString

Methods inherited from class javax.realtime.HighResolutionTime

compareTo, compareTo, equals, equals, getMilliseconds, getNanoseconds, hashCode, set, set, waitForObject

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

frequency

protected int frequency

Constructor Detail

RationalTime

public RationalTime(int frequency)

Construct a new Object of RationalTime Equivalent to new Rational-Time( 1000, 0, frequency)---essentially a cycles-per-second value.

Parameters:

frequency - the frequency value of this RationalTime.

RationalTime

public RationalTime(int frequency,
                    long millis,
                    int nanos)
             throws IllegalArgumentException

Construct a new Object of RationalTime. All arguments must be >= 0.

Parameters:

frequency - the frequency value of this RationalTime.

millis - the milli seconds value of this RationalTime.

nanos - the nano seconds value of this RationalTime.

RationalTime

public RationalTime(int frequency,
                    RelativeTime interval)
             throws IllegalArgumentException

Construct a new Object of RationalTime from the given RelativeTime.

Parameters:

frequency - the frequency value of this RationalTime.

interval - the interval that defines this RationalTime.

Throws:

IllegalArgumentException - if an error occurs

Method Detail

addInterarrivalTo

public void addInterarrivalTo(AbsoluteTime destination)

Add thistime to an AbsoluteTime. It is almost the same dest.add(this, dest) except that it accounts for(ie. divides by) the frequency.

Parameters:

destination - the AbsoluteTime that will be augmented with the interarrival-time associated to this RationalTime.

getFrequency

public int getFrequency()

Gets the frequency associated with this.

Returns:

Return the frequency of this.

getInterarrivalTime

public RelativeTime getInterarrivalTime()

Gets the time duration between two consecutive ticks using frequency.

Returns:

the interarrival-time

getInterarrivalTime

public void getInterarrivalTime(RelativeTime destination)

Gets the time duration between two consecutive ticks using frequency.

Parameters:

destination - the destination for the interarrival-time

set

public void set(long millis,
                int nanos)
         throws IllegalArgumentException

Change the indicated interval of this to the sum of the values of the arguments.

Overrides:

set in class HighResolutionTime

Parameters:

millis - the millisecond component.

nanos - the nanosecond component.

Throws:

IllegalArgumentException - if any of the argument is negative.

setFrequency

public void setFrequency(int frequency)
                  throws ArithmeticException

Set the frequency of this.

Parameters:

frequency - the frequency value.

Throws:

ArithmeticException - if the frequency is not positive.