view src/EDU/oswego/cs/dl/util/concurrent/WaitableLong.java @ 27:511648fa4d64 Version 2.1

Version to 2.1
author Dan Creswell <dan.creswell@gmail.com>
date Mon, 04 Jan 2010 13:00:40 +0000
parents 3dc0c5604566
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/*
  File: WaitableLong.java

  Originally written by Doug Lea and released into the public domain.
  This may be used for any purposes whatsoever without acknowledgment.
  Thanks for the assistance and support of Sun Microsystems Labs,
  and everyone contributing, testing, and using this code.

  History:
  Date       Who                What
  23Jun1998  dl               Create public version
*/

package EDU.oswego.cs.dl.util.concurrent;

/**
 * A class useful for offloading waiting and signalling operations
 * on single long variables. 
 * <p>
 * <p>[<a href="http://gee.cs.oswego.edu/dl/classes/EDU/oswego/cs/dl/util/concurrent/intro.html"> Introduction to this package. </a>]
 **/

public class WaitableLong extends SynchronizedLong {
  /** 
   * Make a new WaitableLong with the given initial value,
   * and using its own internal lock.
   **/
  public WaitableLong(long initialValue) { 
    super(initialValue); 
  }

  /** 
   * Make a new WaitableLong with the given initial value,
   * and using the supplied lock.
   **/
  public WaitableLong(long initialValue, Object lock) { 
    super(initialValue, lock); 
  }


  public long set(long newValue) { 
    synchronized (lock_) {
      lock_.notifyAll();
      return super.set(newValue);
    }
  }

  public boolean commit(long assumedValue, long newValue) {
    synchronized (lock_) {
      boolean success = super.commit(assumedValue, newValue);
      if (success) lock_.notifyAll();
      return success;
    }
  }

  public long increment() { 
    synchronized (lock_) {
      lock_.notifyAll();
      return super.increment();
    }
  }

  public long decrement() { 
    synchronized (lock_) {
      lock_.notifyAll();
      return super.decrement();
    }
  }

  public long add(long amount) { 
    synchronized (lock_) {
      lock_.notifyAll();
      return super.add(amount);
    }
  }

  public long subtract(long amount) { 
    synchronized (lock_) {
      lock_.notifyAll();
      return super.subtract(amount);
    }
  }

  public long multiply(long factor) { 
    synchronized (lock_) {
      lock_.notifyAll();
      return super.multiply(factor);
    }
  }

  public long divide(long factor) { 
    synchronized (lock_) {
      lock_.notifyAll();
      return super.divide(factor);
    }
  }


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

  public void whenEqual(long c, Runnable action) throws InterruptedException {
    synchronized(lock_) {
      while (!(value_ == c)) lock_.wait();
      if (action != null) action.run();
    }
  }

  /**
   * wait until value not equal to c, then run action if nonnull.
   * The action is run with the synchronization lock held.
   **/
  public void whenNotEqual(long c, Runnable action) throws InterruptedException {
    synchronized (lock_) {
      while (!(value_ != c)) lock_.wait();
      if (action != null) action.run();
    }
  }

  /**
   * wait until value less than or equal to c, then run action if nonnull.
   * The action is run with the synchronization lock held.
   **/
  public void whenLessEqual(long c, Runnable action) throws InterruptedException {
    synchronized (lock_) {
      while (!(value_ <= c)) lock_.wait();
      if (action != null) action.run();
    }
  }

  /**
   * wait until value less than c, then run action if nonnull.
   * The action is run with the synchronization lock held.
   **/
  public void whenLess(long c, Runnable action) throws InterruptedException {
    synchronized (lock_) {
      while (!(value_ < c)) lock_.wait();
      if (action != null) action.run();
    }
  }

  /**
   * wait until value greater than or equal to c, then run action if nonnull.
   * The action is run with the synchronization lock held.
   **/
  public void whenGreaterEqual(long c, Runnable action) throws InterruptedException {
    synchronized (lock_) {
      while (!(value_ >= c)) lock_.wait();
      if (action != null) action.run();
    }
  }

  /**
   * wait until value greater than c, then run action if nonnull.
   * The action is run with the synchronization lock held.
   **/
  public void whenGreater(long c, Runnable action) throws InterruptedException {
    synchronized (lock_) {
      while (!(value_ > c)) lock_.wait();
      if (action != null) action.run();
    }
  }

}