--- jsr166/src/test/loops/LockLoops.java	2016/06/08 20:11:01	1.13
+++ jsr166/src/test/loops/LockLoops.java	2016/06/09 15:28:19	1.15
@@ -3,8 +3,9 @@
  * Expert Group and released to the public domain, as explained at
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
+
 /*
- * A simple test program. Feel free to play.
+ * Simple benchmark comparing various locking techniques.
  */
 
 import java.util.*;
@@ -91,6 +92,11 @@ public final class LockLoops {
             Thread.sleep(10);
 
             if (print)
+                System.out.print("ReentrantReadLock    ");
+            new ReentrantReadLockLoop().test(v, nthreads, iters);
+            Thread.sleep(10);
+
+            if (print)
                 System.out.print("ReentrantReadWriteLock");
             new ReentrantReadWriteLockLoop().test(v, nthreads, iters);
             Thread.sleep(10);
@@ -139,8 +145,13 @@ public final class LockLoops {
             Thread.sleep(10);
 
             if (print)
+                System.out.print("StampedLockOptRead");
+            new StampedLockOptimisticReadLoop().test(v, nthreads, iters);
+            Thread.sleep(10);
+
+            if (print)
                 System.out.print("StampedLockReadWrite");
-            new StampedLockReadLoop().test(v, nthreads, iters);
+            new StampedLockReadWriteLoop().test(v, nthreads, iters);
             Thread.sleep(10);
         }
     }
@@ -278,6 +289,24 @@ public final class LockLoops {
         }
     }
 
+    private static class ReentrantReadLockLoop extends LockLoop {
+        private final Lock lock = new ReentrantReadWriteLock().readLock();
+        final int loop(int n) {
+            int sum = 0;
+            while (n-- > 0) {
+                lock.lock();
+                try {
+                    v = LoopHelpers.compute1(v);
+                }
+                finally {
+                    lock.unlock();
+                }
+                sum += LoopHelpers.compute2(v);
+            }
+            return sum;
+        }
+    }
+
     private static class ReentrantReadWriteLockLoop extends LockLoop {
         private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
         final int loop(int n) {
@@ -427,6 +456,22 @@ public final class LockLoops {
                 sum += LoopHelpers.compute2(v);
             }
             return sum;
+        }
+    }
+
+    private static class StampedLockOptimisticReadLoop extends LockLoop {
+        private final StampedLock lock = new StampedLock();
+        final int loop(int n) {
+            int sum = 0;
+            while (n-- > 0) {
+                long stamp;
+                do {
+                    stamp = lock.tryOptimisticRead();
+                    v = LoopHelpers.compute1(v);
+                } while (!lock.validate(stamp));
+                sum += LoopHelpers.compute2(v);
+            }
+            return sum;
         }
     }