1 files changed, 159 insertions, 0 deletions
diff --git a/visualizer/org.eclipse.cdt.visualizer.ui/src/org/eclipse/cdt/visualizer/ui/util/RunnableWithResult.java b/visualizer/org.eclipse.cdt.visualizer.ui/src/org/eclipse/cdt/visualizer/ui/util/RunnableWithResult.java
new file mode 100644
index 00000000000..952d17730da
--- /dev/null
+++ b/visualizer/org.eclipse.cdt.visualizer.ui/src/org/eclipse/cdt/visualizer/ui/util/RunnableWithResult.java
@@ -0,0 +1,159 @@
+/*******************************************************************************
+ * Copyright (c) 2012 Tilera Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     William R. Swanson (Tilera Corporation)
+ *******************************************************************************/
+
+package org.eclipse.cdt.visualizer.ui.util;
+
+import java.util.concurrent.Callable;
+
+
+/**
+ * Runnable object that returns a result object.
+ * 
+ * This is like Future<V> from the concurrent package,
+ * but with a few less bells and whistles.
+ * 
+ * Intended to be used, for example, as follows:
+ * 
+ * RunnableWithResult<X> runnable = new RunnableWithResult<X>() {
+ *   public X call() {
+ *     ... do work, return an X object ...
+ *   }
+ * }
+ * 
+ * Thread thread = new Thread(runnable);
+ * thread.start();
+ * X result = runnable.getResult(0);
+ * 
+ * or, to run it on the UI thread...
+ * 
+ * GUIUtils.execAndWait(runnable);
+ * X result = runnable.getResult(0);
+ * 
+ * Note: if you're invoking this from the UI thread,
+ * it's important to use execAndWait(), so that the runnable
+ * gets a turn on the event loop, otherwise you'll hang the UI!
+ * 
+ */
+public class RunnableWithResult<V>
+	implements Runnable, Callable<V>
+{
+	// --- members ---
+
+	/** Result to return */
+	protected V m_result = null;
+	
+	/** Whether run() has completed */
+	protected boolean m_done = false;
+	
+	
+	// --- constructors/destructors ---
+	
+	/** Constructor. */
+	public RunnableWithResult() {
+	}
+	
+	/** Dispose method. */
+	public void dispose() {
+		m_result = null;
+	}
+
+	
+	// --- accessors ---
+
+	/** Sets result value */
+	public void setResult(V result) {
+		m_result = result;
+	}
+	
+	/** Gets result value. */
+	public V getResult() {
+		return m_result;
+	}
+
+	
+	// --- Runnable implementation ---
+
+	/** Run method.
+	 *  Derived types should override call() rather than this method.
+	 */
+	public void run() {
+		m_done = false;
+		setResult(call());
+		m_done = true;
+		synchronized (this) {
+			notifyAll();
+		}
+	}
+	
+	
+	// --- Callable implementation ---
+	
+	/** Method that returns the value.
+	 *  Default implementation returns null.
+	 */
+	public V call() {
+		return null;
+	}
+
+	
+	// --- methods ---
+	
+	/** Waits for result and returns it. */
+	public V waitForResult() {
+		return waitForResult(0, null);
+	}
+	
+	/** Waits for result and returns it. */
+	public V waitForResult(long timeout) {
+		return waitForResult(timeout, null);
+	}
+	
+	/** Waits for result and returns it.
+	 *  Returns null if specified timeout is exceeded.
+	 */
+	public V waitForResult(long timeout, V defaultValue) {
+		V result = defaultValue;
+		try {
+			if (timeout == 0) {
+				// wait forever
+				// (guard against spurious thread wakeup -- see wait() Javadoc)
+				while (! m_done) {
+					synchronized (this) {
+						this.wait(0);
+					}
+				}
+			}
+			else {
+				// wait until specified timeout
+				// (guard against spurious thread wakeup -- see wait() Javadoc)
+				long then = now();
+				long waitstep = timeout / 10;
+				if (waitstep == 0) waitstep = 1;
+				do {
+					synchronized (this) {
+						this.wait(waitstep);
+					}
+				}
+				while (! m_done && ((now() - then) < timeout));
+			}
+		}
+		catch (InterruptedException e) {
+		}
+		if (m_done) result = getResult();
+		return result;
+	}
+	
+	/** Returns current time in milliseconds. */
+	protected static long now() {
+		return System.currentTimeMillis();
+	}
+}
+