package test;
import java.util.LinkedList;

public class ThreadPool
{
  private final int nThreads;

  private final PoolWorker[] threads;

  private final LinkedList<Runnable> queue;

  public ThreadPool(int nThreads)
  {
    this.nThreads = nThreads;
    queue = new LinkedList<Runnable>();
    threads = new PoolWorker[this.nThreads];

    for (int i = 0; i < this.nThreads; i++)
    {
      threads[i] = new PoolWorker();
      threads[i].start();
    }
  }

  public void execute(Runnable r)
  {
    synchronized (queue)
    {
      queue.addLast(r);
      queue.notifyAll();
    }
  }

  private class PoolWorker extends Thread
  {
    public void run()
    {
      Runnable r;

//      while (true)
//      {
        synchronized (queue)
        {
          while (queue.isEmpty())
          {
            try
            {
              queue.wait();
            } catch (InterruptedException ignored)
            {
            }
          }

          r = (Runnable) queue.removeFirst();
        }

        try
        {
          r.run();
        } catch (RuntimeException e)
        {
        }
//      }
    }
  }
}