--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/EDU/oswego/cs/dl/util/concurrent/Executor.java	Sat Mar 21 11:00:06 2009 +0000
@@ -0,0 +1,66 @@
+/*
+  File: Executor.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
+  19Jun1998  dl               Create public version
+*/
+
+package EDU.oswego.cs.dl.util.concurrent;
+
+/**
+ * Interface for objects that execute Runnables,
+ * as well as various objects that can be wrapped
+ * as Runnables.
+ * The main reason to use Executor throughout a program or
+ * subsystem is to provide flexibility: You can easily
+ * change from using thread-per-task to using pools or
+ * queuing, without needing to change most of your code that
+ * generates tasks.
+ * <p>
+ * The general intent is that execution be asynchronous,
+ * or at least independent of the caller. For example,
+ * one of the simplest implementations of <code>execute</code>
+ * (as performed in ThreadedExecutor)
+ * is <code>new Thread(command).start();</code>.
+ * However, this interface allows implementations that instead
+ * employ queueing or pooling, or perform additional
+ * bookkeeping.
+ * <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 interface Executor {
+  /** 
+   * Execute the given command. This method is guaranteed
+   * only to arrange for execution, that may actually
+   * occur sometime later; for example in a new
+   * thread. However, in fully generic use, callers
+   * should be prepared for execution to occur in
+   * any fashion at all, including immediate direct
+   * execution.
+   * <p>
+   * The method is defined not to throw 
+   * any checked exceptions during execution of the command. Generally,
+   * any problems encountered will be asynchronous and
+   * so must be dealt with via callbacks or error handler
+   * objects. If necessary, any context-dependent 
+   * catastrophic errors encountered during
+   * actions that arrange for execution could be accompanied
+   * by throwing context-dependent unchecked exceptions.
+   * <p>
+   * However, the method does throw InterruptedException:
+   * It will fail to arrange for execution
+   * if the current thread is currently interrupted.
+   * Further, the general contract of the method is to avoid,
+   * suppress, or abort execution if interruption is detected
+   * in any controllable context surrounding execution.
+   **/
+  public void execute(Runnable command) throws InterruptedException;
+
+}