org.apache.river.concurrent

Class TimedReferrer<T>

java.lang.Object

org.apache.river.concurrent.TimedReferrer<T>

All Implemented Interfaces:

Referrer<T>, TimeBomb, UntouchableReferrer<T>

class TimedReferrer<T>
extends Object
implements UntouchableReferrer<T>, TimeBomb

Author:

Peter Firmstone.

Field Summary

Fields

Modifier and Type	Field and Description
private long	clock
private boolean	enqued
private Object	lock
private TimedRefQueue	queue
private long	read
private T	referent

Constructor Summary

Constructors

Constructor and Description
TimedReferrer(T k, TimedRefQueue q)

Method Summary

Modifier and Type	Method and Description
void	clear()
boolean	enqueue()
boolean	equals(Object o) Equals is calculated on IDENTITY or EQUALITY.
T	get()
int	hashCode() Standard hashCode calculation for IDENTITY based references, where k is the referent.
boolean	isEnqueued()
T	lookDontTouch()
String	toString()
void	updateClock(long time)

Methods inherited from class java.lang.Object

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

Field Detail

clock

private volatile long clock

read

private volatile long read

queue

private final TimedRefQueue queue

referent

private final T referent

enqued

private volatile boolean enqued

lock

private final Object lock

Constructor Detail

TimedReferrer

TimedReferrer(T k,
              TimedRefQueue q)

Method Detail

get

public T get()

Specified by:

get in interface Referrer<T>

See Also:

Reference.get()

clear

public void clear()

Specified by:

clear in interface Referrer<T>

See Also:

Reference.clear()

isEnqueued

public boolean isEnqueued()

Specified by:

isEnqueued in interface Referrer<T>

Returns:

true if enqueued.

See Also:

Reference.isEnqueued()

enqueue

public boolean enqueue()

Specified by:

enqueue in interface Referrer<T>

Returns:

true if successfully enqueued.

See Also:

Reference.enqueue()

updateClock

public void updateClock(long time)

Specified by:

updateClock in interface TimeBomb

equals

public boolean equals(Object o)

Description copied from interface: Referrer

Equals is calculated on IDENTITY or EQUALITY.

IDENTITY calculation:

if (this == o) return true;
if (!(o instanceof Referrer)) return false;
Object k1 = get();
Object k2 = ((Referrer) o).get();
if ( k1 != null && k1 == k2 ) return true;
return ( k1 == null && k2 == null && hashCode() == o.hashCode());

EQUALITY calculation:

if (this == o) return true; // Same reference.
if (!(o instanceof Referrer)) return false;
Object k1 = get();
Object k2 = ((Referrer) o).get();
if ( k1 != null && k1.equals(k2)) return true;
return ( k1 == null && k2 == null && hashCode() == o.hashCode());



Specified by:

equals in interface Referrer<T>

Overrides:

equals in class Object

Returns:

true if equal

See Also:

Ref

hashCode

public int hashCode()

Description copied from interface: Referrer

Standard hashCode calculation for IDENTITY based references, where k is the referent. This may be stored in a final field:

int hash = 7;
hash = 29 * hash + System.identityHashCode(k);
hash = 29 * hash + k.getClass().hashCode();


Standard hashCode calculation for EQUALITY based references, where k is the referent:

int hash = 7;
hash = 29 * hash + k.hashCode();
hash = 29 * hash + k.getClass().hashCode();


The hash must be calculated during construction and if the reference is cleared, the recorded hashCode returned. While the referent remains reachable the hashCode must be calculated each time.

Specified by:

hashCode in interface Referrer<T>

Overrides:

hashCode in class Object

Returns:

hash

toString

public String toString()

Overrides:

toString in class Object

lookDontTouch

public T lookDontTouch()

Specified by:

lookDontTouch in interface UntouchableReferrer<T>