--- jsr166/src/test/loops/LockLoops.java	2009/10/29 23:09:07	1.3
+++ jsr166/src/test/loops/LockLoops.java	2016/06/08 20:01:45	1.12
@@ -1,15 +1,15 @@
 /*
  * Written by Doug Lea with assistance from members of JCP JSR-166
  * Expert Group and released to the public domain, as explained at
- * http://creativecommons.org/licenses/publicdomain
+ * http://creativecommons.org/publicdomain/zero/1.0/
  */
 /*
  * A simple test program. Feel free to play.
  */
 
+import java.util.*;
 import java.util.concurrent.*;
 import java.util.concurrent.locks.*;
-import java.util.*;
 
 public final class LockLoops {
     static final ExecutorService pool = Executors.newCachedThreadPool();
@@ -18,7 +18,8 @@ public final class LockLoops {
     static boolean doBuiltin = true;
     static boolean doReadWrite = true;
     static boolean doSemaphore = true;
-    static boolean doFair =  true;
+    static boolean doStampedLock = true;
+    static boolean doFair = true;
 
     public static void main(String[] args) throws Exception {
         int maxThreads = 100;
@@ -93,7 +94,6 @@ public final class LockLoops {
                 System.out.print("ReentrantReadWriteLock");
             new ReentrantReadWriteLockLoop().test(v, nthreads, iters);
             Thread.sleep(10);
-
         }
 
         if (doSemaphore) {
@@ -106,7 +106,6 @@ public final class LockLoops {
                 System.out.print("FairSemaphore         ");
             new FairSemaphoreLoop().test(v, nthreads, iters);
             Thread.sleep(10);
-
         }
 
         if (doFair) {
@@ -126,12 +125,22 @@ public final class LockLoops {
                 new FairReentrantReadWriteLockLoop().test(v, nthreads, iters);
                 Thread.sleep(10);
             }
-
         }
 
+        if (doStampedLock) {
+            if (print)
+                System.out.print("StampedLockWrite   ");
+            new StampedLockWriteLoop().test(v, nthreads, iters);
+            Thread.sleep(10);
+
+            if (print)
+                System.out.print("StampedLockRead    ");
+            new StampedLockReadLoop().test(v, nthreads, iters);
+            Thread.sleep(10);
+        }
     }
 
-    static abstract class LockLoop implements Runnable {
+    abstract static class LockLoop implements Runnable {
         int v;
         int iters;
         volatile int result;
@@ -150,7 +159,7 @@ public final class LockLoops {
             if (print) {
                 long tpi = time / (iters * nthreads);
                 System.out.print("\t" + LoopHelpers.rightJustify(tpi) + " ns per update");
-                //                double secs = (double)(time) / 1000000000.0;
+                //                double secs = (double) time / 1000000000.0;
                 //                System.out.print("\t " + secs + "s run time");
                 System.out.println();
             }
@@ -176,7 +185,7 @@ public final class LockLoops {
         final int loop(int n) {
             int sum = 0;
             while (n-- > 0) {
-                synchronized(this) {
+                synchronized (this) {
                     v = LoopHelpers.compute1(v);
                 }
                 sum += LoopHelpers.compute2(v);
@@ -198,7 +207,7 @@ public final class LockLoops {
     }
 
     private static class NoLockVolatileLoop extends LockLoop {
-        volatile private int vv;
+        private volatile int vv;
         final int loop(int n) {
             int sum = 0;
             while (n-- > 0) {
@@ -211,7 +220,7 @@ public final class LockLoops {
     }
 
     private static class ReentrantLockLoop extends LockLoop {
-        final private ReentrantLock lock = new ReentrantLock();
+        private final ReentrantLock lock = new ReentrantLock();
         final int loop(int n) {
             int sum = 0;
             while (n-- > 0) {
@@ -229,7 +238,7 @@ public final class LockLoops {
     }
 
     private static class FairReentrantLockLoop extends LockLoop {
-        final private ReentrantLock lock = new ReentrantLock(true);
+        private final ReentrantLock lock = new ReentrantLock(true);
         final int loop(int n) {
             int sum = 0;
             while (n-- > 0) {
@@ -247,7 +256,7 @@ public final class LockLoops {
     }
 
     private static class ReentrantWriteLockLoop extends LockLoop {
-        final private Lock lock = new ReentrantReadWriteLock().writeLock();
+        private final Lock lock = new ReentrantReadWriteLock().writeLock();
         final int loop(int n) {
             int sum = 0;
             while (n-- > 0) {
@@ -265,7 +274,7 @@ public final class LockLoops {
     }
 
     private static class ReentrantReadWriteLockLoop extends LockLoop {
-        final private ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
+        private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
         final int loop(int n) {
             int sum = 0;
             while (n-- > 0) {
@@ -309,7 +318,7 @@ public final class LockLoops {
     }
 
     private static class SemaphoreLoop extends LockLoop {
-        final private Semaphore sem = new Semaphore(1, false);
+        private final Semaphore sem = new Semaphore(1, false);
         final int loop(int n) {
             int sum = 0;
             try {
@@ -330,8 +339,9 @@ public final class LockLoops {
             return sum;
         }
     }
+
     private static class FairSemaphoreLoop extends LockLoop {
-        final private Semaphore sem = new Semaphore(1, true);
+        private final Semaphore sem = new Semaphore(1, true);
         final int loop(int n) {
             int sum = 0;
             try {
@@ -354,7 +364,7 @@ public final class LockLoops {
     }
 
     private static class FairReentrantReadWriteLockLoop extends LockLoop {
-        final private ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
+        private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
         final int loop(int n) {
             int sum = 0;
             while (n-- > 0) {
@@ -379,5 +389,39 @@ public final class LockLoops {
         }
     }
 
+    private static class StampedLockWriteLoop extends LockLoop {
+        private final StampedLock lock = new StampedLock();
+        final int loop(int n) {
+            int sum = 0;
+            while (n-- > 0) {
+                long stamp = lock.writeLock();
+                try {
+                    v = LoopHelpers.compute1(v);
+                }
+                finally {
+                    lock.unlockWrite(stamp);
+                }
+                sum += LoopHelpers.compute2(v);
+            }
+            return sum;
+        }
+    }
 
+    private static class StampedLockReadLoop extends LockLoop {
+        private final StampedLock lock = new StampedLock();
+        final int loop(int n) {
+            int sum = 0;
+            while (n-- > 0) {
+                long stamp = lock.readLock();
+                try {
+                    v = LoopHelpers.compute1(v);
+                }
+                finally {
+                    lock.unlockRead(stamp);
+                }
+                sum += LoopHelpers.compute2(v);
+            }
+            return sum;
+        }
+    }
 }