DelayedFutureTask

gistfile1.java

package org.robotninjas.audio;

import com.google.common.base.Ticker;
import com.google.common.primitives.Longs;

import java.util.concurrent.Callable;
import java.util.concurrent.Delayed;
import java.util.concurrent.FutureTask;
import java.util.concurrent.TimeUnit;

import static java.util.concurrent.TimeUnit.NANOSECONDS;

public class DelayedFutureTask<V> extends FutureTask<V> implements Delayed {

  private final Ticker ticker;
  private final long deadline;

  public DelayedFutureTask(Callable<V> callable, Ticker ticker, long delay, TimeUnit unit) {
    super(callable);
    this.ticker = ticker;
    this.deadline = ticker.read() + NANOSECONDS.convert(delay, unit);
  }

  @Override
  public long getDelay(TimeUnit unit) {
    final long now = ticker.read();
    final long remaining = deadline - now;
    return unit.convert(remaining, NANOSECONDS);
  }

  @Override
  public int compareTo(Delayed o) {

    if (o == this) {
      return 0;
    }

    if (o instanceof DelayedFutureTask) {
      final DelayedFutureTask<?> other = (DelayedFutureTask) o;
      return Longs.compare(deadline, other.deadline);
    }
    return Longs.compare(getDelay(NANOSECONDS), o.getDelay(NANOSECONDS));

  }

}