EDU.oswego.cs.dl.util.concurrent
Class WaitableRef

java.lang.Object
  EDU.oswego.cs.dl.util.concurrent.SynchronizedVariable
      EDU.oswego.cs.dl.util.concurrent.SynchronizedRef
          EDU.oswego.cs.dl.util.concurrent.WaitableRef

All Implemented Interfaces:

Executor

public class WaitableRef
extends SynchronizedRef

A class useful for offloading synch for Object reference instance variables.

[ Introduction to this package. ]

Field Summary

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

value_

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

lock_

Constructor Summary

WaitableRef(java.lang.Object initialValue)
Create a WaitableRef initially holding the given reference and using its own internal lock.

WaitableRef(java.lang.Object initialValue, java.lang.Object lock)
Make a new WaitableRef with the given initial value, and using the supplied lock.

Method Summary

boolean	commit(java.lang.Object assumedValue, java.lang.Object newValue) Set value to newValue only if it is currently assumedValue.
java.lang.Object	set(java.lang.Object newValue) Set to newValue.
void	whenEqual(java.lang.Object c, java.lang.Runnable action) Wait until value equals c, then run action if nonnull.
void	whenNotEqual(java.lang.Object c, java.lang.Runnable action) wait until value not equal to c, then run action if nonnull.
void	whenNotNull(java.lang.Runnable action) wait until value is nonnull, then run action if nonnull.
void	whenNull(java.lang.Runnable action) Wait until value is null, then run action if nonnull.

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

get, swap

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

execute, getLock

Methods inherited from class java.lang.Object

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

Constructor Detail

WaitableRef

public WaitableRef(java.lang.Object initialValue)

Create a WaitableRef initially holding the given reference and using its own internal lock.

WaitableRef

public WaitableRef(java.lang.Object initialValue,
                   java.lang.Object lock)

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

Method Detail

set

public java.lang.Object set(java.lang.Object newValue)

Description copied from class: SynchronizedRef

Set to newValue.

Overrides:

set in class SynchronizedRef

Returns:

the old value

commit

public boolean commit(java.lang.Object assumedValue,
                      java.lang.Object newValue)

Description copied from class: SynchronizedRef

Set value to newValue only if it is currently assumedValue.

Overrides:

commit in class SynchronizedRef

Returns:

true if successful

whenNull

public void whenNull(java.lang.Runnable action)
              throws java.lang.InterruptedException

Wait until value is null, then run action if nonnull. The action is run with the synchronization lock held.

Throws:

java.lang.InterruptedException

whenNotNull

public void whenNotNull(java.lang.Runnable action)
                 throws java.lang.InterruptedException

wait until value is nonnull, then run action if nonnull. The action is run with the synchronization lock held.

Throws:

java.lang.InterruptedException

whenEqual

public void whenEqual(java.lang.Object c,
                      java.lang.Runnable action)
               throws java.lang.InterruptedException

Wait until value equals c, then run action if nonnull. The action is run with the synchronization lock held.

Throws:

java.lang.InterruptedException

whenNotEqual

public void whenNotEqual(java.lang.Object c,
                         java.lang.Runnable action)
                  throws java.lang.InterruptedException

wait until value not equal to c, then run action if nonnull. The action is run with the synchronization lock held.

Throws:

java.lang.InterruptedException