X-Git-Url: https://feistymeow.org/gitweb/?a=blobdiff_plain;f=kona%2Fsrc%2Forg%2Ffeistymeow%2Fprocess%2Fethread.java;h=e23d7d89d33e0c1dedf940c63d8a1fd58b1f3e0e;hb=ef338226ccf699c8d8a149d9b74e9888175c7099;hp=913af7a1a04351003d1e8c91a1c42016657aa546;hpb=f2aa040bbb4b45acf77d75675934176e52d26df5;p=feisty_meow.git

diff --git a/kona/src/org/feistymeow/process/ethread.java b/kona/src/org/feistymeow/process/ethread.java
index 913af7a1..e23d7d89 100644
--- a/kona/src/org/feistymeow/process/ethread.java
+++ b/kona/src/org/feistymeow/process/ethread.java
@@ -8,8 +8,8 @@ import org.apache.commons.logging.LogFactory;
  * 
  * @author Chris Koeritz
  * @copyright Copyright (c) 2010-$now By Feisty Meow Concerns Ltd.
- * @license This file is free software; you can modify and redistribute it under the terms of the
- *          Apache License v2.0: http://www.apache.org/licenses/LICENSE-2.0
+ * @license This file is free software; you can modify and redistribute it under the terms of the Apache License v2.0:
+ *          http://www.apache.org/licenses/LICENSE-2.0
  */
 public abstract class ethread implements Runnable
 {
@@ -19,14 +19,37 @@ public abstract class ethread implements Runnable
 	private volatile Thread c_RealThread = null;
 	// provides synchronization for the thread.
 	private volatile Object c_lock = new Object();
+	// this is the timing period, for a timed thread. if zero, then this is a single shot thread.
+	private long c_period = 0;
+	// records whether the thread should shut down or not.
+	private boolean c_stopThread = false;
+	// snooze between checks on the stop timer.
+	final long SNOOZE_PERIOD = 20;
 
 	/**
-	 * creates a new ethread without starting it.
+	 * creates a new single-shot ethread without starting it. this type of thread will run just once.
 	 */
 	public ethread()
 	{
 	}
 
+	/**
+	 * creates a new periodic ethread without starting it. this type of thread runs every "period" milliseconds until stopped or until the
+	 * performActivity method returns false.
+	 */
+	public ethread(long period)
+	{
+		c_period = period;
+	}
+
+	/**
+	 * this is the main function that derived classes must implement. it does the actual work that the thread is intended to perform. note
+	 * that the derived version must not do anything to cause the thread to be ripped out while performActivity is still being invoked. the
+	 * return value should be true if the thread can continue executing. this is meaningless for single shot threads executed via runOnce, but
+	 * matters for the periodic threads started with runPeriodic.
+	 */
+	abstract public boolean performActivity();
+
 	/**
 	 * Begins execution of the thread.
 	 */
@@ -45,8 +68,28 @@ public abstract class ethread implements Runnable
 	 * Stops execution of the thread, or at least attempts to.
 	 */
 	public void stop()
+	{
+		cancel();
+		while (true) {
+			if (threadAlive()) {
+				try {
+					Thread.sleep(40);
+				} catch (InterruptedException e) {
+					// ignoring this since we'll keep snoozing as needed.
+				}
+			} else {
+				break;
+			}
+		}
+	}
+
+	/**
+	 * Signals the thread to stop executing, but does not wait for it.
+	 */
+	void cancel()
 	{
 		synchronized (c_lock) {
+			c_stopThread = true;
 			Thread goAway = c_RealThread;
 			c_RealThread = null;
 			if (null != goAway) {
@@ -56,39 +99,63 @@ public abstract class ethread implements Runnable
 	}
 
 	/**
-	 * this is the main function that derived classes must implement. it does the actual work that
-	 * the thread is intended to perform. note that the derived version must not do anything to
-	 * cause the thread to be ripped out while performActivity is still being invoked.
+	 * Returns true if the thread object is still alive. this does not necessarily mean it is currently active.
 	 */
-	// hmmm: should this stay void, or use a bool status to indicate if the thread should die?
-	abstract void performActivity();
+	public boolean threadAlive()
+	{
+		synchronized (c_lock) {
+			return this.c_RealThread != null;
+		}
+	}
 
 	/**
-	 * Returns true if the thread isn't null.
+	 * returns true if the thread has been told to stop running.
 	 */
-	public boolean threadRunning()
+	public boolean shouldStop()
 	{
 		synchronized (c_lock) {
-			return (null != this.c_RealThread);
+			return c_stopThread;
 		}
 	}
 
 	/**
-	 * this is the override from Runnable that allows us to call our own performActivity method.
-	 * implementors should not override this; they should override performActivity instead.
+	 * this is the override from Runnable that allows us to call our own performActivity method. implementors should not override this; they
+	 * should override performActivity instead.
 	 */
+	@Override
 	public void run()
 	{
-		synchronized (c_lock) {
-			if (false == threadRunning()) {
-				return; // stopped before it ever started. how can this be? we just got invoked.
+		if (!threadAlive()) {
+			return; // stopped before it ever started. how can this be? we just got invoked.
+		}
+		try {
+			while (true) {
+				boolean keepGoing = performActivity();
+				if (!keepGoing) {
+					c_logger.debug("thread returned false, signifying it wants to exit.  now dropping it.");
+					break;
+				}
+				if (c_period == 0) {
+					// not a periodic thread, so we're done now.
+					break;
+				}
+				long nextRun = System.currentTimeMillis() + c_period;
+				while (System.currentTimeMillis() < nextRun) {
+					if (shouldStop()) {
+						break;
+					}
+					try {
+						Thread.sleep(SNOOZE_PERIOD);
+					} catch (InterruptedException e) {
+						// well, we'll hit it again soon.
+					}
+				}
 			}
-			performActivity();
+		} catch (Throwable t) {
+			c_logger.info("exception thrown from performActivity: " + t.getLocalizedMessage(), t);
 		}
+		// reset the thread held since we're leaving right now.
+		c_stopThread = true;
+		c_RealThread = null;
 	}
 }
-
-// hmmm: still in progress...
-// hmmm: missing the timed features of ethread.
-// hmmm: missing cancel, exempt_stop, sleep_time, should_stop,
-