[infinispan-commits] Infinispan SVN: r435 - in trunk/core/src: test/java/org/infinispan/util and 1 other directories.

[infinispan-commits at lists.jboss.org]

Author: manik.surtani at jboss.com
Date: 2009-06-10 22:51:56 -0400 (Wed, 10 Jun 2009)
New Revision: 435

Added:
   trunk/core/src/main/java/org/infinispan/util/concurrent/ValueNotifier.java
   trunk/core/src/test/java/org/infinispan/util/concurrent/
   trunk/core/src/test/java/org/infinispan/util/concurrent/ValueNotifierTest.java
Log:
Added value notifier to watch for value changes, based on AQS

Added: trunk/core/src/main/java/org/infinispan/util/concurrent/ValueNotifier.java
===================================================================
--- trunk/core/src/main/java/org/infinispan/util/concurrent/ValueNotifier.java	                        (rev 0)
+++ trunk/core/src/main/java/org/infinispan/util/concurrent/ValueNotifier.java	2009-06-11 02:51:56 UTC (rev 435)
@@ -0,0 +1,56 @@
+package org.infinispan.util.concurrent;
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.AbstractQueuedSynchronizer;
+
+/**
+ * Allows threads to watch a variable and be notified when the state of the variable reaches a specific value.
+ * <p/>
+ * E.g.,
+ * <p/>
+ * ValueNotifier v = new ValueNotifier(0);
+ * <p/>
+ * Thread1:
+ * <p/>
+ * v.setValue(10);
+ * <p/>
+ * Thread2:
+ * <p/>
+ * v.awaitValue(5); // will block until another thread sets the value to 5
+ *
+ * @author Manik Surtani
+ * @since 4.0
+ */
+public class ValueNotifier extends AbstractQueuedSynchronizer {
+   private static final long serialVersionUID = 1744280161777661090l;
+
+   public ValueNotifier(int initValue) {
+      setState(initValue);
+   }
+
+   @Override
+   public final int tryAcquireShared(int value) {
+      // return 1 if we allow the requestor to proceed, -1 if we want the requestor to block.
+      return getState() == value ? 1 : -1;
+   }
+
+   @Override
+   public final boolean tryReleaseShared(int state) {
+      // used as a mechanism to set the state of the Sync.
+      setState(state);
+      return true;
+   }
+
+   public final void setValue(int value) {
+      // do not use setState() directly since this won't notify parked threads.
+      releaseShared(value);
+   }
+
+   public final void awaitValue(int value) throws InterruptedException {
+      acquireSharedInterruptibly(value);
+   }
+
+   public final boolean awaitValue(int value, long time, TimeUnit unit) throws InterruptedException {
+      return tryAcquireSharedNanos(value, unit.toNanos(time));
+   }
+}


Property changes on: trunk/core/src/main/java/org/infinispan/util/concurrent/ValueNotifier.java
___________________________________________________________________
Name: svn:keywords
   + Id Revision
Name: svn:eol-style
   + LF

Added: trunk/core/src/test/java/org/infinispan/util/concurrent/ValueNotifierTest.java
===================================================================
--- trunk/core/src/test/java/org/infinispan/util/concurrent/ValueNotifierTest.java	                        (rev 0)
+++ trunk/core/src/test/java/org/infinispan/util/concurrent/ValueNotifierTest.java	2009-06-11 02:51:56 UTC (rev 435)
@@ -0,0 +1,65 @@
+package org.infinispan.util.concurrent;
+
+import org.testng.annotations.Test;
+
+import java.util.LinkedList;
+import java.util.List;
+
+ at Test(groups = "unit")
+public class ValueNotifierTest {
+   public void testNotifier() throws InterruptedException {
+      final ValueNotifier vn = new ValueNotifier(10);
+      final List<Integer> threadsCompleted = new LinkedList<Integer>();
+
+
+      Thread t1 = new Thread() {
+         public void run() {
+            try {
+               vn.awaitValue(50);
+               threadsCompleted.add(1);
+            } catch (Exception e) {
+               throw new RuntimeException(e);
+            }
+         }
+      };
+
+      Thread t2 = new Thread() {
+         public void run() {
+            try {
+               vn.awaitValue(50);
+               threadsCompleted.add(2);
+            } catch (Exception e) {
+               throw new RuntimeException(e);
+            }
+         }
+      };
+
+      Thread t3 = new Thread() {
+         public void run() {
+            try {
+               vn.awaitValue(40);
+               threadsCompleted.add(3);
+            } catch (Exception e) {
+               throw new RuntimeException(e);
+            }
+         }
+      };
+
+      t1.start();
+      t2.start();
+      t3.start();
+
+      Thread.sleep(100);
+      assert threadsCompleted.isEmpty();
+      vn.setValue(50);
+      Thread.sleep(100);
+      assert threadsCompleted.size() == 2;
+      assert threadsCompleted.contains(1);
+      assert threadsCompleted.contains(2);
+
+      vn.setValue(40);
+      Thread.sleep(100);
+      assert threadsCompleted.size() == 3;
+      assert threadsCompleted.contains(3);
+   }
+}


Property changes on: trunk/core/src/test/java/org/infinispan/util/concurrent/ValueNotifierTest.java
___________________________________________________________________
Name: svn:keywords
   + Id Revision
Name: svn:eol-style
   + LF