ContinueImpl.java

package au.com.phiware.util.concurrent;

import java.util.Date;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;

public class ContinueImpl implements Continue {
	private boolean isPaused;
    private ReentrantLock pauseLock = new ReentrantLock();
    private Condition unpaused = pauseLock.newCondition();

    /* (non-Javadoc)
	 * @see au.com.phiware.util.concurrent.Continue#checkIn()
	 */
    @Override
	public void checkIn() throws InterruptedException {
    	if (isPaused) {
    	    pauseLock.lock();
            try {
            	while (isPaused)
            		unpaused.await();
            } finally {
            	pauseLock.unlock();
            }
    	}
    }

    /* (non-Javadoc)
	 * @see au.com.phiware.util.concurrent.Continue#checkInUntil(java.util.Date)
	 */
    @Override
	public void checkInUntil(Date deadline) throws InterruptedException {
    	if (isPaused) {
    	    pauseLock.lock();
            try {
            	while (isPaused)
            		unpaused.awaitUntil(deadline);
            } finally {
            	pauseLock.unlock();
            }
    	}
    }

    /* (non-Javadoc)
	 * @see au.com.phiware.util.concurrent.Continue#checkIn(long)
	 */
    @Override
	public void checkIn(long nanosTimeout) throws InterruptedException {
    	if (isPaused) {
    	    pauseLock.lock();
            try {
            	while (isPaused)
            		unpaused.awaitNanos(nanosTimeout);
            } finally {
            	pauseLock.unlock();
            }
    	}
    }

    /* (non-Javadoc)
	 * @see au.com.phiware.util.concurrent.Continue#checkIn(long, java.util.concurrent.TimeUnit)
	 */
    @Override
	public void checkIn(long time, TimeUnit unit) throws InterruptedException {
    	if (isPaused) {
    	    pauseLock.lock();
            try {
            	while (isPaused)
            		unpaused.await(time, unit);
            } finally {
            	pauseLock.unlock();
            }
    	}
    }

    /* (non-Javadoc)
	 * @see au.com.phiware.util.concurrent.Continue#checkInUninterruptibly()
	 */
    @Override
	public void checkInUninterruptibly() {
    	if (isPaused) {
    	    pauseLock.lock();
            try {
            	while (isPaused)
            		unpaused.awaitUninterruptibly();
            } finally {
            	pauseLock.unlock();
            }
    	}
    }

    /* (non-Javadoc)
	 * @see au.com.phiware.util.concurrent.Continue#isPaused()
	 */
    @Override
	public boolean isPaused() {
    	return isPaused;
    }

    /* (non-Javadoc)
	 * @see au.com.phiware.util.concurrent.Continue#pause()
	 */
    @Override
	public void pause() {
	    pauseLock.lock();
        try {
        	isPaused = true;
        } finally {
        	pauseLock.unlock();
        }
    }

	/* (non-Javadoc)
	 * @see au.com.phiware.util.concurrent.Continue#resume()
	 */
	@Override
	public void resume() {
    	pauseLock.lock();
        try {
            if (isPaused) {
                isPaused = false;
                unpaused.signalAll();
            }
        } finally {
        	pauseLock.unlock();
        }
    }
}