--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/util/concurrent/ConcurrentLinkedQueue/ConcurrentQueueLoops.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,146 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file:
+ *
+ * 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
+ */
+
+/*
+ * @test
+ * @bug 4486658
+ * @compile -source 1.5 ConcurrentQueueLoops.java
+ * @run main/timeout=230 ConcurrentQueueLoops
+ * @summary Checks that a set of threads can repeatedly get and modify items
+ */
+
+import java.util.*;
+import java.util.concurrent.*;
+import java.util.concurrent.atomic.*;
+
+public class ConcurrentQueueLoops {
+    static final ExecutorService pool = Executors.newCachedThreadPool();
+    static AtomicInteger totalItems;
+    static boolean print = false;
+
+    public static void main(String[] args) throws Exception {
+        int maxStages = 8;
+        int items = 100000;
+
+        if (args.length > 0)
+            maxStages = Integer.parseInt(args[0]);
+
+        print = false;
+        System.out.println("Warmup...");
+        oneRun(1, items);
+        Thread.sleep(100);
+        oneRun(1, items);
+        Thread.sleep(100);
+        print = true;
+
+        for (int i = 1; i <= maxStages; i += (i+1) >>> 1) {
+            oneRun(i, items);
+        }
+        pool.shutdown();
+        if (! pool.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS))
+            throw new Error();
+   }
+
+    static class Stage implements Callable<Integer> {
+        final Queue<Integer> queue;
+        final CyclicBarrier barrier;
+        int items;
+        Stage (Queue<Integer> q, CyclicBarrier b, int items) {
+            queue = q;
+            barrier = b;
+            this.items = items;
+        }
+
+        public Integer call() {
+            // Repeatedly take something from queue if possible,
+            // transform it, and put back in.
+            try {
+                barrier.await();
+                int l = 4321;
+                int takes = 0;
+                for (;;) {
+                    Integer item = queue.poll();
+                    if (item != null) {
+                        ++takes;
+                        l = LoopHelpers.compute2(item.intValue());
+                    }
+                    else if (takes != 0) {
+                        totalItems.getAndAdd(-takes);
+                        takes = 0;
+                    }
+                    else if (totalItems.get() <= 0)
+                        break;
+                    l = LoopHelpers.compute1(l);
+                    if (items > 0) {
+                        --items;
+                        queue.offer(new Integer(l));
+                    }
+                    else if ( (l & (3 << 5)) == 0) // spinwait
+                        Thread.sleep(1);
+                }
+                return new Integer(l);
+            }
+            catch (Exception ie) {
+                ie.printStackTrace();
+                throw new Error("Call loop failed");
+            }
+        }
+    }
+
+    static void oneRun(int n, int items) throws Exception {
+        Queue<Integer> q = new ConcurrentLinkedQueue<Integer>();
+        LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
+        CyclicBarrier barrier = new CyclicBarrier(n + 1, timer);
+        totalItems = new AtomicInteger(n * items);
+        ArrayList<Future<Integer>> results = new ArrayList<Future<Integer>>(n);
+        for (int i = 0; i < n; ++i)
+            results.add(pool.submit(new Stage(q, barrier, items)));
+
+        if (print)
+            System.out.print("Threads: " + n + "\t:");
+        barrier.await();
+        int total = 0;
+        for (int i = 0; i < n; ++i) {
+            Future<Integer> f = results.get(i);
+            Integer r = f.get();
+            total += r.intValue();
+        }
+        long endTime = System.nanoTime();
+        long time = endTime - timer.startTime;
+        if (print)
+            System.out.println(LoopHelpers.rightJustify(time / (items * n)) + " ns per item");
+        if (total == 0) // avoid overoptimization
+            System.out.println("useless result: " + total);
+
+    }
+}