waitableshort.java

来自「一个很好的微工作流内核」· Java 代码 · 共 168 行

/*
  File: WaitableShort.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 short 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 WaitableShort extends SynchronizedShort {
  /** 
   * Make a new WaitableShort with the given initial value,
   * and using its own internal lock.
   **/
  public WaitableShort(short initialValue) { 
    super(initialValue); 
  }

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


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

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

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

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

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

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

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

  public short divide(short 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(short 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(short 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(short 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(short 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(short 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(short c, Runnable action) throws InterruptedException {
    synchronized (lock_) {
      while (!(value_ > c)) lock_.wait();
      if (action != null) action.run();
    }
  }

}