Package EDU.oswego.cs.dl.util.concurrent

Class SynchronizedDouble

java.lang.Object

EDU.oswego.cs.dl.util.concurrent.SynchronizedVariable

EDU.oswego.cs.dl.util.concurrent.SynchronizedDouble

All Implemented Interfaces:

Executor, Cloneable, Comparable

Direct Known Subclasses:

WaitableDouble

public class SynchronizedDouble
extends SynchronizedVariable
implements Comparable, Cloneable

A class useful for offloading synch for double instance variables.

[ Introduction to this package. ]

Field Summary

Fields

Modifier and Type	Field	Description
protected double	value_

Fields inherited from class EDU.oswego.cs.dl.util.concurrent.SynchronizedVariable

lock_

Constructor Summary

Constructors

Constructor	Description
SynchronizedDouble(double initialValue)	Make a new SynchronizedDouble with the given initial value, and using its own internal lock.
SynchronizedDouble(double initialValue, Object lock)	Make a new SynchronizedDouble with the given initial value, and using the supplied lock.

Method Summary

Modifier and Type	Method	Description
double	add(double amount)	Add amount to value (i.e., set value += amount)
boolean	commit(double assumedValue, double newValue)	Set value to newValue only if it is currently assumedValue.
int	compareTo(double other)
int	compareTo(SynchronizedDouble other)
int	compareTo(Object other)
double	divide(double factor)	Divide value by factor (i.e., set value /= factor)
boolean	equals(Object other)
double	get()	Return the current value
int	hashCode()
double	multiply(double factor)	Multiply value by factor (i.e., set value *= factor)
double	set(double newValue)	Set to newValue.
double	subtract(double amount)	Subtract amount from value (i.e., set value -= amount)
double	swap(SynchronizedDouble other)	Atomically swap values with another SynchronizedDouble.
String	toString()

Methods inherited from class EDU.oswego.cs.dl.util.concurrent.SynchronizedVariable

execute, getLock

Methods inherited from class java.lang.Object

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

Field Detail

value_

protected double value_

Constructor Detail

SynchronizedDouble

public SynchronizedDouble(double initialValue)

Make a new SynchronizedDouble with the given initial value, and using its own internal lock.

SynchronizedDouble

public SynchronizedDouble(double initialValue,
                          Object lock)

Make a new SynchronizedDouble with the given initial value, and using the supplied lock.

Method Detail

get

public final double get()

Return the current value

set

public double set(double newValue)

Set to newValue.

Returns:

the old value

commit

public boolean commit(double assumedValue,
                      double newValue)

Set value to newValue only if it is currently assumedValue.

Returns:

true if successful

swap

public double swap(SynchronizedDouble other)

Atomically swap values with another SynchronizedDouble. Uses identityHashCode to avoid deadlock when two SynchronizedDoubles attempt to simultaneously swap with each other. (Note: Ordering via identyHashCode is not strictly guaranteed by the language specification to return unique, orderable values, but in practice JVMs rely on them being unique.)

Returns:

the new value

add

public double add(double amount)

Add amount to value (i.e., set value += amount)

Returns:

the new value

subtract

public double subtract(double amount)

Subtract amount from value (i.e., set value -= amount)

Returns:

the new value

multiply

public double multiply(double factor)

Multiply value by factor (i.e., set value *= factor)

Returns:

the new value

divide

public double divide(double factor)

Divide value by factor (i.e., set value /= factor)

Returns:

the new value

compareTo

public int compareTo(double other)

compareTo

public int compareTo(SynchronizedDouble other)

compareTo

public int compareTo(Object other)

Specified by:

compareTo in interface Comparable

equals

public boolean equals(Object other)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object