Merge

jdk/make/java/java/FILES_java.gmk

@@ -286,11 +286,18 @@ JAVA_JAVA_java = \
     java/util/concurrent/ExecutorService.java \
     java/util/concurrent/ExecutorCompletionService.java \
     java/util/concurrent/Executors.java \
+    java/util/concurrent/ForkJoinPool.java \
+    java/util/concurrent/ForkJoinTask.java \
+    java/util/concurrent/ForkJoinWorkerThread.java \
     java/util/concurrent/Future.java \
     java/util/concurrent/FutureTask.java \
     java/util/concurrent/LinkedBlockingDeque.java \
     java/util/concurrent/LinkedBlockingQueue.java \
+    java/util/concurrent/LinkedTransferQueue.java \
+    java/util/concurrent/Phaser.java \
     java/util/concurrent/PriorityBlockingQueue.java \
+    java/util/concurrent/RecursiveAction.java \
+    java/util/concurrent/RecursiveTask.java \
     java/util/concurrent/RejectedExecutionException.java \
     java/util/concurrent/RejectedExecutionHandler.java \
     java/util/concurrent/RunnableFuture.java \
@@ -301,9 +308,11 @@ JAVA_JAVA_java = \
     java/util/concurrent/Semaphore.java \
     java/util/concurrent/SynchronousQueue.java \
     java/util/concurrent/ThreadFactory.java \
+    java/util/concurrent/ThreadLocalRandom.java \
     java/util/concurrent/ThreadPoolExecutor.java \
     java/util/concurrent/TimeUnit.java \
     java/util/concurrent/TimeoutException.java \
+    java/util/concurrent/TransferQueue.java \
     java/util/concurrent/atomic/AtomicBoolean.java \
     java/util/concurrent/atomic/AtomicInteger.java \
     java/util/concurrent/atomic/AtomicIntegerArray.java \

jdk/src/share/classes/java/util/AbstractList.java

@@ -256,9 +256,8 @@ public abstract class AbstractList<E> extends AbstractCollection<E> implements L
     public boolean addAll(int index, Collection<? extends E> c) {
         rangeCheckForAdd(index);
         boolean modified = false;
-        Iterator<? extends E> e = c.iterator();
-        while (e.hasNext()) {
-            add(index++, e.next());
+        for (E e : c) {
+            add(index++, e);
             modified = true;
         }
         return modified;

jdk/src/share/classes/java/util/AbstractQueue.java

@@ -183,11 +183,9 @@ public abstract class AbstractQueue<E>
         if (c == this)
             throw new IllegalArgumentException();
         boolean modified = false;
-        Iterator<? extends E> e = c.iterator();
-        while (e.hasNext()) {
-            if (add(e.next()))
+        for (E e : c)
+            if (add(e))
                 modified = true;
-        }
         return modified;
     }
 

jdk/src/share/classes/java/util/HashMap.java

@@ -448,11 +448,9 @@ public class HashMap<K,V>
     }
 
     private void putAllForCreate(Map<? extends K, ? extends V> m) {
-        for (Iterator<? extends Map.Entry<? extends K, ? extends V>> i = m.entrySet().iterator(); i.hasNext(); ) {
-            Map.Entry<? extends K, ? extends V> e = i.next();
+        for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
             putForCreate(e.getKey(), e.getValue());
     }
-    }
 
     /**
      * Rehashes the contents of this map into a new array with a
@@ -536,11 +534,9 @@ public class HashMap<K,V>
                 resize(newCapacity);
         }
 
-        for (Iterator<? extends Map.Entry<? extends K, ? extends V>> i = m.entrySet().iterator(); i.hasNext(); ) {
-            Map.Entry<? extends K, ? extends V> e = i.next();
+        for (Map.Entry<? extends K, ? extends V> e : m.entrySet())
             put(e.getKey(), e.getValue());
     }
-    }
 
     /**
      * Removes the mapping for the specified key from this map if present.

jdk/src/share/classes/java/util/HashSet.java

@@ -280,8 +280,8 @@ public class HashSet<E>
         s.writeInt(map.size());
 
         // Write out all elements in the proper order.
-        for (Iterator i=map.keySet().iterator(); i.hasNext(); )
-            s.writeObject(i.next());
+        for (E e : map.keySet())
+            s.writeObject(e);
     }
 
     /**

jdk/src/share/classes/java/util/Random.java

@@ -50,6 +50,18 @@ import sun.misc.Unsafe;
  * <p>
  * Many applications will find the method {@link Math#random} simpler to use.
  *
+ * <p>Instances of {@code java.util.Random} are threadsafe.
+ * However, the concurrent use of the same {@code java.util.Random}
+ * instance across threads may encounter contention and consequent
+ * poor performance. Consider instead using
+ * {@link java.util.concurrent.ThreadLocalRandom} in multithreaded
+ * designs.
+ *
+ * <p>Instances of {@code java.util.Random} are not cryptographically
+ * secure.  Consider instead using {@link java.security.SecureRandom} to
+ * get a cryptographically secure pseudo-random number generator for use
+ * by security-sensitive applications.
+ *
  * @author  Frank Yellin
  * @since   1.0
  */

jdk/src/share/classes/java/util/concurrent/ArrayBlockingQueue.java

@@ -218,8 +218,8 @@ public class ArrayBlockingQueue<E> extends AbstractQueue<E>
         if (capacity < c.size())
             throw new IllegalArgumentException();
 
-        for (Iterator<? extends E> it = c.iterator(); it.hasNext();)
-            add(it.next());
+        for (E e : c)
+            add(e);
     }
 
     /**

jdk/src/share/classes/java/util/concurrent/ConcurrentLinkedQueue.java

@@ -250,8 +250,8 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
      *         of its elements are null
      */
     public ConcurrentLinkedQueue(Collection<? extends E> c) {
-        for (Iterator<? extends E> it = c.iterator(); it.hasNext();)
-            add(it.next());
+        for (E e : c)
+            add(e);
     }
 
     // Have to override just to update the javadoc

jdk/src/share/classes/java/util/concurrent/ConcurrentSkipListMap.java

@@ -895,7 +895,7 @@ public class ConcurrentSkipListMap<K,V> extends AbstractMap<K,V>
                 if (n != null) {
                     Node<K,V> f = n.next;
                     if (n != b.next)               // inconsistent read
-                        break;;
+                        break;
                     Object v = n.value;
                     if (v == null) {               // n is deleted
                         n.helpDelete(b, f);

jdk/src/share/classes/java/util/concurrent/CountDownLatch.java

@@ -148,7 +148,8 @@ import java.util.concurrent.atomic.*;
  *
  * </pre>
  *
- * <p>Memory consistency effects: Actions in a thread prior to calling
+ * <p>Memory consistency effects: Until the count reaches
+ * zero, actions in a thread prior to calling
  * {@code countDown()}
  * <a href="package-summary.html#MemoryVisibility"><i>happen-before</i></a>
  * actions following a successful return from a corresponding

jdk/src/share/classes/java/util/concurrent/ExecutorService.java

@@ -332,8 +332,8 @@ public interface ExecutorService extends Executor {
      * @param tasks the collection of tasks
      * @return the result returned by one of the tasks
      * @throws InterruptedException if interrupted while waiting
-     * @throws NullPointerException if tasks or any of its elements
-     *         are <tt>null</tt>
+     * @throws NullPointerException if tasks or any element task
+     *         subject to execution is <tt>null</tt>
      * @throws IllegalArgumentException if tasks is empty
      * @throws ExecutionException if no task successfully completes
      * @throws RejectedExecutionException if tasks cannot be scheduled
@@ -356,8 +356,8 @@ public interface ExecutorService extends Executor {
      * @param unit the time unit of the timeout argument
      * @return the result returned by one of the tasks.
      * @throws InterruptedException if interrupted while waiting
-     * @throws NullPointerException if tasks, any of its elements, or
-     *         unit are <tt>null</tt>
+     * @throws NullPointerException if tasks, or unit, or any element
+     *         task subject to execution is <tt>null</tt>
      * @throws TimeoutException if the given timeout elapses before
      *         any task successfully completes
      * @throws ExecutionException if no task successfully completes

jdk/src/share/classes/java/util/concurrent/ForkJoinWorkerThread.java

@@ -0,0 +1,827 @@
+/*
+ * 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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * 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
+ */
+
+package java.util.concurrent;
+
+import java.util.Collection;
+
+/**
+ * A thread managed by a {@link ForkJoinPool}.  This class is
+ * subclassable solely for the sake of adding functionality -- there
+ * are no overridable methods dealing with scheduling or execution.
+ * However, you can override initialization and termination methods
+ * surrounding the main task processing loop.  If you do create such a
+ * subclass, you will also need to supply a custom {@link
+ * ForkJoinPool.ForkJoinWorkerThreadFactory} to use it in a {@code
+ * ForkJoinPool}.
+ *
+ * @since 1.7
+ * @author Doug Lea
+ */
+public class ForkJoinWorkerThread extends Thread {
+    /*
+     * Algorithm overview:
+     *
+     * 1. Work-Stealing: Work-stealing queues are special forms of
+     * Deques that support only three of the four possible
+     * end-operations -- push, pop, and deq (aka steal), and only do
+     * so under the constraints that push and pop are called only from
+     * the owning thread, while deq may be called from other threads.
+     * (If you are unfamiliar with them, you probably want to read
+     * Herlihy and Shavit's book "The Art of Multiprocessor
+     * programming", chapter 16 describing these in more detail before
+     * proceeding.)  The main work-stealing queue design is roughly
+     * similar to "Dynamic Circular Work-Stealing Deque" by David
+     * Chase and Yossi Lev, SPAA 2005
+     * (http://research.sun.com/scalable/pubs/index.html).  The main
+     * difference ultimately stems from gc requirements that we null
+     * out taken slots as soon as we can, to maintain as small a
+     * footprint as possible even in programs generating huge numbers
+     * of tasks. To accomplish this, we shift the CAS arbitrating pop
+     * vs deq (steal) from being on the indices ("base" and "sp") to
+     * the slots themselves (mainly via method "casSlotNull()"). So,
+     * both a successful pop and deq mainly entail CAS'ing a non-null
+     * slot to null.  Because we rely on CASes of references, we do
+     * not need tag bits on base or sp.  They are simple ints as used
+     * in any circular array-based queue (see for example ArrayDeque).
+     * Updates to the indices must still be ordered in a way that
+     * guarantees that (sp - base) > 0 means the queue is empty, but
+     * otherwise may err on the side of possibly making the queue
+     * appear nonempty when a push, pop, or deq have not fully
+     * committed. Note that this means that the deq operation,
+     * considered individually, is not wait-free. One thief cannot
+     * successfully continue until another in-progress one (or, if
+     * previously empty, a push) completes.  However, in the
+     * aggregate, we ensure at least probabilistic
+     * non-blockingness. If an attempted steal fails, a thief always
+     * chooses a different random victim target to try next. So, in
+     * order for one thief to progress, it suffices for any
+     * in-progress deq or new push on any empty queue to complete. One
+     * reason this works well here is that apparently-nonempty often
+     * means soon-to-be-stealable, which gives threads a chance to
+     * activate if necessary before stealing (see below).
+     *
+     * This approach also enables support for "async mode" where local
+     * task processing is in FIFO, not LIFO order; simply by using a
+     * version of deq rather than pop when locallyFifo is true (as set
+     * by the ForkJoinPool).  This allows use in message-passing
+     * frameworks in which tasks are never joined.
+     *
+     * Efficient implementation of this approach currently relies on
+     * an uncomfortable amount of "Unsafe" mechanics. To maintain
+     * correct orderings, reads and writes of variable base require
+     * volatile ordering.  Variable sp does not require volatile write
+     * but needs cheaper store-ordering on writes.  Because they are
+     * protected by volatile base reads, reads of the queue array and
+     * its slots do not need volatile load semantics, but writes (in
+     * push) require store order and CASes (in pop and deq) require
+     * (volatile) CAS semantics.  (See "Idempotent work stealing" by
+     * Michael, Saraswat, and Vechev, PPoPP 2009
+     * http://portal.acm.org/citation.cfm?id=1504186 for an algorithm
+     * with similar properties, but without support for nulling
+     * slots.)  Since these combinations aren't supported using
+     * ordinary volatiles, the only way to accomplish these
+     * efficiently is to use direct Unsafe calls. (Using external
+     * AtomicIntegers and AtomicReferenceArrays for the indices and
+     * array is significantly slower because of memory locality and
+     * indirection effects.)
+     *
+     * Further, performance on most platforms is very sensitive to
+     * placement and sizing of the (resizable) queue array.  Even
+     * though these queues don't usually become all that big, the
+     * initial size must be large enough to counteract cache
+     * contention effects across multiple queues (especially in the
+     * presence of GC cardmarking). Also, to improve thread-locality,
+     * queues are currently initialized immediately after the thread
+     * gets the initial signal to start processing tasks.  However,
+     * all queue-related methods except pushTask are written in a way
+     * that allows them to instead be lazily allocated and/or disposed
+     * of when empty. All together, these low-level implementation
+     * choices produce as much as a factor of 4 performance
+     * improvement compared to naive implementations, and enable the
+     * processing of billions of tasks per second, sometimes at the
+     * expense of ugliness.
+     *
+     * 2. Run control: The primary run control is based on a global
+     * counter (activeCount) held by the pool. It uses an algorithm
+     * similar to that in Herlihy and Shavit section 17.6 to cause
+     * threads to eventually block when all threads declare they are
+     * inactive. For this to work, threads must be declared active
+     * when executing tasks, and before stealing a task. They must be
+     * inactive before blocking on the Pool Barrier (awaiting a new
+     * submission or other Pool event). In between, there is some free
+     * play which we take advantage of to avoid contention and rapid
+     * flickering of the global activeCount: If inactive, we activate
+     * only if a victim queue appears to be nonempty (see above).
+     * Similarly, a thread tries to inactivate only after a full scan
+     * of other threads.  The net effect is that contention on
+     * activeCount is rarely a measurable performance issue. (There
+     * are also a few other cases where we scan for work rather than
+     * retry/block upon contention.)
+     *
+     * 3. Selection control. We maintain policy of always choosing to
+     * run local tasks rather than stealing, and always trying to
+     * steal tasks before trying to run a new submission. All steals
+     * are currently performed in randomly-chosen deq-order. It may be
+     * worthwhile to bias these with locality / anti-locality
+     * information, but doing this well probably requires more
+     * lower-level information from JVMs than currently provided.
+     */
+
+    /**
+     * Capacity of work-stealing queue array upon initialization.
+     * Must be a power of two. Initial size must be at least 2, but is
+     * padded to minimize cache effects.
+     */
+    private static final int INITIAL_QUEUE_CAPACITY = 1 << 13;
+
+    /**
+     * Maximum work-stealing queue array size.  Must be less than or
+     * equal to 1 << 28 to ensure lack of index wraparound. (This
+     * is less than usual bounds, because we need leftshift by 3
+     * to be in int range).
+     */
+    private static final int MAXIMUM_QUEUE_CAPACITY = 1 << 28;
+
+    /**
+     * The pool this thread works in. Accessed directly by ForkJoinTask.
+     */
+    final ForkJoinPool pool;
+
+    /**
+     * The work-stealing queue array. Size must be a power of two.
+     * Initialized when thread starts, to improve memory locality.
+     */
+    private ForkJoinTask<?>[] queue;
+
+    /**
+     * Index (mod queue.length) of next queue slot to push to or pop
+     * from. It is written only by owner thread, via ordered store.
+     * Both sp and base are allowed to wrap around on overflow, but
+     * (sp - base) still estimates size.
+     */
+    private volatile int sp;
+
+    /**
+     * Index (mod queue.length) of least valid queue slot, which is
+     * always the next position to steal from if nonempty.
+     */
+    private volatile int base;
+
+    /**
+     * Activity status. When true, this worker is considered active.
+     * Must be false upon construction. It must be true when executing
+     * tasks, and BEFORE stealing a task. It must be false before
+     * calling pool.sync.
+     */
+    private boolean active;
+
+    /**
+     * Run state of this worker. Supports simple versions of the usual
+     * shutdown/shutdownNow control.
+     */
+    private volatile int runState;
+
+    /**
+     * Seed for random number generator for choosing steal victims.
+     * Uses Marsaglia xorshift. Must be nonzero upon initialization.
+     */
+    private int seed;
+
+    /**
+     * Number of steals, transferred to pool when idle
+     */
+    private int stealCount;
+
+    /**
+     * Index of this worker in pool array. Set once by pool before
+     * running, and accessed directly by pool during cleanup etc.
+     */
+    int poolIndex;
+
+    /**
+     * The last barrier event waited for. Accessed in pool callback
+     * methods, but only by current thread.
+     */
+    long lastEventCount;
+
+    /**
+     * True if use local fifo, not default lifo, for local polling
+     */
+    private boolean locallyFifo;
+
+    /**
+     * Creates a ForkJoinWorkerThread operating in the given pool.
+     *
+     * @param pool the pool this thread works in
+     * @throws NullPointerException if pool is null
+     */
+    protected ForkJoinWorkerThread(ForkJoinPool pool) {
+        if (pool == null) throw new NullPointerException();
+        this.pool = pool;
+        // Note: poolIndex is set by pool during construction
+        // Remaining initialization is deferred to onStart
+    }
+
+    // Public access methods
+
+    /**
+     * Returns the pool hosting this thread.
+     *
+     * @return the pool
+     */
+    public ForkJoinPool getPool() {
+        return pool;
+    }
+
+    /**
+     * Returns the index number of this thread in its pool.  The
+     * returned value ranges from zero to the maximum number of
+     * threads (minus one) that have ever been created in the pool.
+     * This method may be useful for applications that track status or
+     * collect results per-worker rather than per-task.
+     *
+     * @return the index number
+     */
+    public int getPoolIndex() {
+        return poolIndex;
+    }
+
+    /**
+     * Establishes local first-in-first-out scheduling mode for forked
+     * tasks that are never joined.
+     *
+     * @param async if true, use locally FIFO scheduling
+     */
+    void setAsyncMode(boolean async) {
+        locallyFifo = async;
+    }
+
+    // Runstate management
+
+    // Runstate values. Order matters
+    private static final int RUNNING     = 0;
+    private static final int SHUTDOWN    = 1;
+    private static final int TERMINATING = 2;
+    private static final int TERMINATED  = 3;
+
+    final boolean isShutdown()    { return runState >= SHUTDOWN;  }
+    final boolean isTerminating() { return runState >= TERMINATING;  }
+    final boolean isTerminated()  { return runState == TERMINATED; }
+    final boolean shutdown()      { return transitionRunStateTo(SHUTDOWN); }
+    final boolean shutdownNow()   { return transitionRunStateTo(TERMINATING); }
+
+    /**
+     * Transitions to at least the given state.
+     *
+     * @return {@code true} if not already at least at given state
+     */
+    private boolean transitionRunStateTo(int state) {
+        for (;;) {
+            int s = runState;
+            if (s >= state)
+                return false;
+            if (UNSAFE.compareAndSwapInt(this, runStateOffset, s, state))
+                return true;
+        }
+    }
+
+    /**
+     * Tries to set status to active; fails on contention.
+     */
+    private boolean tryActivate() {
+        if (!active) {
+            if (!pool.tryIncrementActiveCount())
+                return false;
+            active = true;
+        }
+        return true;
+    }
+
+    /**
+     * Tries to set status to inactive; fails on contention.
+     */
+    private boolean tryInactivate() {
+        if (active) {
+            if (!pool.tryDecrementActiveCount())
+                return false;
+            active = false;
+        }
+        return true;
+    }
+
+    /**
+     * Computes next value for random victim probe.  Scans don't
+     * require a very high quality generator, but also not a crummy
+     * one.  Marsaglia xor-shift is cheap and works well.
+     */
+    private static int xorShift(int r) {
+        r ^= (r << 13);
+        r ^= (r >>> 17);
+        return r ^ (r << 5);
+    }
+
+    // Lifecycle methods
+
+    /**
+     * This method is required to be public, but should never be
+     * called explicitly. It performs the main run loop to execute
+     * ForkJoinTasks.
+     */
+    public void run() {
+        Throwable exception = null;
+        try {
+            onStart();
+            pool.sync(this); // await first pool event
+            mainLoop();
+        } catch (Throwable ex) {
+            exception = ex;
+        } finally {
+            onTermination(exception);
+        }
+    }
+
+    /**
+     * Executes tasks until shut down.
+     */
+    private void mainLoop() {
+        while (!isShutdown()) {
+            ForkJoinTask<?> t = pollTask();
+            if (t != null || (t = pollSubmission()) != null)
+                t.quietlyExec();
+            else if (tryInactivate())
+                pool.sync(this);
+        }
+    }
+
+    /**
+     * Initializes internal state after construction but before
+     * processing any tasks. If you override this method, you must
+     * invoke super.onStart() at the beginning of the method.
+     * Initialization requires care: Most fields must have legal
+     * default values, to ensure that attempted accesses from other
+     * threads work correctly even before this thread starts
+     * processing tasks.
+     */
+    protected void onStart() {
+        // Allocate while starting to improve chances of thread-local
+        // isolation
+        queue = new ForkJoinTask<?>[INITIAL_QUEUE_CAPACITY];
+        // Initial value of seed need not be especially random but
+        // should differ across workers and must be nonzero
+        int p = poolIndex + 1;
+        seed = p + (p << 8) + (p << 16) + (p << 24); // spread bits
+    }
+
+    /**
+     * Performs cleanup associated with termination of this worker
+     * thread.  If you override this method, you must invoke
+     * {@code super.onTermination} at the end of the overridden method.
+     *
+     * @param exception the exception causing this thread to abort due
+     * to an unrecoverable error, or {@code null} if completed normally
+     */
+    protected void onTermination(Throwable exception) {
+        // Execute remaining local tasks unless aborting or terminating
+        while (exception == null && pool.isProcessingTasks() && base != sp) {
+            try {
+                ForkJoinTask<?> t = popTask();
+                if (t != null)
+                    t.quietlyExec();
+            } catch (Throwable ex) {
+                exception = ex;
+            }
+        }
+        // Cancel other tasks, transition status, notify pool, and
+        // propagate exception to uncaught exception handler
+        try {
+            do {} while (!tryInactivate()); // ensure inactive
+            cancelTasks();
+            runState = TERMINATED;
+            pool.workerTerminated(this);
+        } catch (Throwable ex) {        // Shouldn't ever happen
+            if (exception == null)      // but if so, at least rethrown
+                exception = ex;
+        } finally {
+            if (exception != null)
+                ForkJoinTask.rethrowException(exception);
+        }
+    }
+
+    // Intrinsics-based support for queue operations.
+
+    private static long slotOffset(int i) {
+        return ((long) i << qShift) + qBase;
+    }
+
+    /**
+     * Adds in store-order the given task at given slot of q to null.
+     * Caller must ensure q is non-null and index is in range.
+     */
+    private static void setSlot(ForkJoinTask<?>[] q, int i,
+                                ForkJoinTask<?> t) {
+        UNSAFE.putOrderedObject(q, slotOffset(i), t);
+    }
+
+    /**
+     * CAS given slot of q to null. Caller must ensure q is non-null
+     * and index is in range.
+     */
+    private static boolean casSlotNull(ForkJoinTask<?>[] q, int i,
+                                       ForkJoinTask<?> t) {
+        return UNSAFE.compareAndSwapObject(q, slotOffset(i), t, null);
+    }
+
+    /**
+     * Sets sp in store-order.
+     */
+    private void storeSp(int s) {
+        UNSAFE.putOrderedInt(this, spOffset, s);
+    }
+
+    // Main queue methods
+
+    /**
+     * Pushes a task. Called only by current thread.
+     *
+     * @param t the task. Caller must ensure non-null.
+     */
+    final void pushTask(ForkJoinTask<?> t) {
+        ForkJoinTask<?>[] q = queue;
+        int mask = q.length - 1;
+        int s = sp;
+        setSlot(q, s & mask, t);
+        storeSp(++s);
+        if ((s -= base) == 1)
+            pool.signalWork();
+        else if (s >= mask)
+            growQueue();
+    }
+
+    /**
+     * Tries to take a task from the base of the queue, failing if
+     * either empty or contended.
+     *
+     * @return a task, or null if none or contended
+     */
+    final ForkJoinTask<?> deqTask() {
+        ForkJoinTask<?> t;
+        ForkJoinTask<?>[] q;
+        int i;
+        int b;
+        if (sp != (b = base) &&
+            (q = queue) != null && // must read q after b
+            (t = q[i = (q.length - 1) & b]) != null &&
+            casSlotNull(q, i, t)) {
+            base = b + 1;
+            return t;
+        }
+        return null;
+    }
+
+    /**
+     * Tries to take a task from the base of own queue, activating if
+     * necessary, failing only if empty. Called only by current thread.
+     *
+     * @return a task, or null if none
+     */
+    final ForkJoinTask<?> locallyDeqTask() {
+        int b;
+        while (sp != (b = base)) {
+            if (tryActivate()) {
+                ForkJoinTask<?>[] q = queue;
+                int i = (q.length - 1) & b;
+                ForkJoinTask<?> t = q[i];
+                if (t != null && casSlotNull(q, i, t)) {
+                    base = b + 1;
+                    return t;
+                }
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Returns a popped task, or null if empty. Ensures active status
+     * if non-null. Called only by current thread.
+     */
+    final ForkJoinTask<?> popTask() {
+        int s = sp;
+        while (s != base) {
+            if (tryActivate()) {
+                ForkJoinTask<?>[] q = queue;
+                int mask = q.length - 1;
+                int i = (s - 1) & mask;
+                ForkJoinTask<?> t = q[i];
+                if (t == null || !casSlotNull(q, i, t))
+                    break;
+                storeSp(s - 1);
+                return t;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Specialized version of popTask to pop only if
+     * topmost element is the given task. Called only
+     * by current thread while active.
+     *
+     * @param t the task. Caller must ensure non-null.
+     */
+    final boolean unpushTask(ForkJoinTask<?> t) {
+        ForkJoinTask<?>[] q = queue;
+        int mask = q.length - 1;
+        int s = sp - 1;
+        if (casSlotNull(q, s & mask, t)) {
+            storeSp(s);
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Returns next task or null if empty or contended
+     */
+    final ForkJoinTask<?> peekTask() {
+        ForkJoinTask<?>[] q = queue;
+        if (q == null)
+            return null;
+        int mask = q.length - 1;
+        int i = locallyFifo ? base : (sp - 1);
+        return q[i & mask];
+    }
+
+    /**
+     * Doubles queue array size. Transfers elements by emulating
+     * steals (deqs) from old array and placing, oldest first, into
+     * new array.
+     */
+    private void growQueue() {
+        ForkJoinTask<?>[] oldQ = queue;
+        int oldSize = oldQ.length;
+        int newSize = oldSize << 1;
+        if (newSize > MAXIMUM_QUEUE_CAPACITY)
+            throw new RejectedExecutionException("Queue capacity exceeded");
+        ForkJoinTask<?>[] newQ = queue = new ForkJoinTask<?>[newSize];
+
+        int b = base;
+        int bf = b + oldSize;
+        int oldMask = oldSize - 1;
+        int newMask = newSize - 1;
+        do {
+            int oldIndex = b & oldMask;
+            ForkJoinTask<?> t = oldQ[oldIndex];
+            if (t != null && !casSlotNull(oldQ, oldIndex, t))
+                t = null;
+            setSlot(newQ, b & newMask, t);
+        } while (++b != bf);
+        pool.signalWork();
+    }
+
+    /**
+     * Tries to steal a task from another worker. Starts at a random
+     * index of workers array, and probes workers until finding one
+     * with non-empty queue or finding that all are empty.  It
+     * randomly selects the first n probes. If these are empty, it
+     * resorts to a full circular traversal, which is necessary to
+     * accurately set active status by caller. Also restarts if pool
+     * events occurred since last scan, which forces refresh of
+     * workers array, in case barrier was associated with resize.
+     *
+     * This method must be both fast and quiet -- usually avoiding
+     * memory accesses that could disrupt cache sharing etc other than
+     * those needed to check for and take tasks. This accounts for,
+     * among other things, updating random seed in place without
+     * storing it until exit.
+     *
+     * @return a task, or null if none found
+     */
+    private ForkJoinTask<?> scan() {
+        ForkJoinTask<?> t = null;
+        int r = seed;                    // extract once to keep scan quiet
+        ForkJoinWorkerThread[] ws;       // refreshed on outer loop
+        int mask;                        // must be power 2 minus 1 and > 0
+        outer:do {
+            if ((ws = pool.workers) != null && (mask = ws.length - 1) > 0) {
+                int idx = r;
+                int probes = ~mask;      // use random index while negative
+                for (;;) {
+                    r = xorShift(r);     // update random seed
+                    ForkJoinWorkerThread v = ws[mask & idx];
+                    if (v == null || v.sp == v.base) {
+                        if (probes <= mask)
+                            idx = (probes++ < 0) ? r : (idx + 1);
+                        else
+                            break;
+                    }
+                    else if (!tryActivate() || (t = v.deqTask()) == null)
+                        continue outer;  // restart on contention
+                    else
+                        break outer;
+                }
+            }
+        } while (pool.hasNewSyncEvent(this)); // retry on pool events
+        seed = r;
+        return t;
+    }
+
+    /**
+     * Gets and removes a local or stolen task.
+     *
+     * @return a task, if available
+     */
+    final ForkJoinTask<?> pollTask() {
+        ForkJoinTask<?> t = locallyFifo ? locallyDeqTask() : popTask();
+        if (t == null && (t = scan()) != null)
+            ++stealCount;
+        return t;
+    }
+
+    /**
+     * Gets a local task.
+     *
+     * @return a task, if available
+     */
+    final ForkJoinTask<?> pollLocalTask() {
+        return locallyFifo ? locallyDeqTask() : popTask();
+    }
+
+    /**
+     * Returns a pool submission, if one exists, activating first.
+     *
+     * @return a submission, if available
+     */
+    private ForkJoinTask<?> pollSubmission() {
+        ForkJoinPool p = pool;
+        while (p.hasQueuedSubmissions()) {
+            ForkJoinTask<?> t;
+            if (tryActivate() && (t = p.pollSubmission()) != null)
+                return t;
+        }
+        return null;
+    }
+
+    // Methods accessed only by Pool
+
+    /**
+     * Removes and cancels all tasks in queue.  Can be called from any
+     * thread.
+     */
+    final void cancelTasks() {
+        ForkJoinTask<?> t;
+        while (base != sp && (t = deqTask()) != null)
+            t.cancelIgnoringExceptions();
+    }
+
+    /**
+     * Drains tasks to given collection c.
+     *
+     * @return the number of tasks drained
+     */
+    final int drainTasksTo(Collection<? super ForkJoinTask<?>> c) {
+        int n = 0;
+        ForkJoinTask<?> t;
+        while (base != sp && (t = deqTask()) != null) {
+            c.add(t);
+            ++n;
+        }
+        return n;
+    }
+
+    /**
+     * Gets and clears steal count for accumulation by pool.  Called
+     * only when known to be idle (in pool.sync and termination).
+     */
+    final int getAndClearStealCount() {
+        int sc = stealCount;
+        stealCount = 0;
+        return sc;
+    }
+
+    /**
+     * Returns {@code true} if at least one worker in the given array
+     * appears to have at least one queued task.
+     *
+     * @param ws array of workers
+     */
+    static boolean hasQueuedTasks(ForkJoinWorkerThread[] ws) {
+        if (ws != null) {
+            int len = ws.length;
+            for (int j = 0; j < 2; ++j) { // need two passes for clean sweep
+                for (int i = 0; i < len; ++i) {
+                    ForkJoinWorkerThread w = ws[i];
+                    if (w != null && w.sp != w.base)
+                        return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    // Support methods for ForkJoinTask
+
+    /**
+     * Returns an estimate of the number of tasks in the queue.
+     */
+    final int getQueueSize() {
+        // suppress momentarily negative values
+        return Math.max(0, sp - base);
+    }
+
+    /**
+     * Returns an estimate of the number of tasks, offset by a
+     * function of number of idle workers.
+     */
+    final int getEstimatedSurplusTaskCount() {
+        // The halving approximates weighting idle vs non-idle workers
+        return (sp - base) - (pool.getIdleThreadCount() >>> 1);
+    }
+
+    /**
+     * Scans, returning early if joinMe done.
+     */
+    final ForkJoinTask<?> scanWhileJoining(ForkJoinTask<?> joinMe) {
+        ForkJoinTask<?> t = pollTask();
+        if (t != null && joinMe.status < 0 && sp == base) {
+            pushTask(t); // unsteal if done and this task would be stealable
+            t = null;
+        }
+        return t;
+    }
+
+    /**
+     * Runs tasks until {@code pool.isQuiescent()}.
+     */
+    final void helpQuiescePool() {
+        for (;;) {
+            ForkJoinTask<?> t = pollTask();
+            if (t != null)
+                t.quietlyExec();
+            else if (tryInactivate() && pool.isQuiescent())
+                break;
+        }
+        do {} while (!tryActivate()); // re-activate on exit
+    }
+
+    // Unsafe mechanics
+
+    private static final sun.misc.Unsafe UNSAFE = sun.misc.Unsafe.getUnsafe();
+    private static final long spOffset =
+        objectFieldOffset("sp", ForkJoinWorkerThread.class);
+    private static final long runStateOffset =
+        objectFieldOffset("runState", ForkJoinWorkerThread.class);
+    private static final long qBase;
+    private static final int qShift;
+
+    static {
+        qBase = UNSAFE.arrayBaseOffset(ForkJoinTask[].class);
+        int s = UNSAFE.arrayIndexScale(ForkJoinTask[].class);
+        if ((s & (s-1)) != 0)
+            throw new Error("data type scale not a power of two");
+        qShift = 31 - Integer.numberOfLeadingZeros(s);
+    }
+
+    private static long objectFieldOffset(String field, Class<?> klazz) {
+        try {
+            return UNSAFE.objectFieldOffset(klazz.getDeclaredField(field));
+        } catch (NoSuchFieldException e) {
+            // Convert Exception to corresponding Error
+            NoSuchFieldError error = new NoSuchFieldError(field);
+            error.initCause(e);
+            throw error;
+        }
+    }
+}

jdk/src/share/classes/java/util/concurrent/RecursiveAction.java

@@ -0,0 +1,179 @@
+/*
+ * 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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * 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
+ */
+
+package java.util.concurrent;
+
+/**
+ * A recursive resultless {@link ForkJoinTask}.  This class
+ * establishes conventions to parameterize resultless actions as
+ * {@code Void} {@code ForkJoinTask}s. Because {@code null} is the
+ * only valid value of type {@code Void}, methods such as join always
+ * return {@code null} upon completion.
+ *
+ * <p><b>Sample Usages.</b> Here is a sketch of a ForkJoin sort that
+ * sorts a given {@code long[]} array:
+ *
+ *  <pre> {@code
+ * class SortTask extends RecursiveAction {
+ *   final long[] array; final int lo; final int hi;
+ *   SortTask(long[] array, int lo, int hi) {
+ *     this.array = array; this.lo = lo; this.hi = hi;
+ *   }
+ *   protected void compute() {
+ *     if (hi - lo < THRESHOLD)
+ *       sequentiallySort(array, lo, hi);
+ *     else {
+ *       int mid = (lo + hi) >>> 1;
+ *       invokeAll(new SortTask(array, lo, mid),
+ *                 new SortTask(array, mid, hi));
+ *       merge(array, lo, hi);
+ *     }
+ *   }
+ * }}</pre>
+ *
+ * You could then sort {@code anArray} by creating {@code new
+ * SortTask(anArray, 0, anArray.length-1) } and invoking it in a
+ * ForkJoinPool.  As a more concrete simple example, the following
+ * task increments each element of an array:
+ *  <pre> {@code
+ * class IncrementTask extends RecursiveAction {
+ *   final long[] array; final int lo; final int hi;
+ *   IncrementTask(long[] array, int lo, int hi) {
+ *     this.array = array; this.lo = lo; this.hi = hi;
+ *   }
+ *   protected void compute() {
+ *     if (hi - lo < THRESHOLD) {
+ *       for (int i = lo; i < hi; ++i)
+ *         array[i]++;
+ *     }
+ *     else {
+ *       int mid = (lo + hi) >>> 1;
+ *       invokeAll(new IncrementTask(array, lo, mid),
+ *                 new IncrementTask(array, mid, hi));
+ *     }
+ *   }
+ * }}</pre>
+ *
+ * <p>The following example illustrates some refinements and idioms
+ * that may lead to better performance: RecursiveActions need not be
+ * fully recursive, so long as they maintain the basic
+ * divide-and-conquer approach. Here is a class that sums the squares
+ * of each element of a double array, by subdividing out only the
+ * right-hand-sides of repeated divisions by two, and keeping track of
+ * them with a chain of {@code next} references. It uses a dynamic
+ * threshold based on method {@code getSurplusQueuedTaskCount}, but
+ * counterbalances potential excess partitioning by directly
+ * performing leaf actions on unstolen tasks rather than further
+ * subdividing.
+ *
+ *  <pre> {@code
+ * double sumOfSquares(ForkJoinPool pool, double[] array) {
+ *   int n = array.length;
+ *   Applyer a = new Applyer(array, 0, n, null);
+ *   pool.invoke(a);
+ *   return a.result;
+ * }
+ *
+ * class Applyer extends RecursiveAction {
+ *   final double[] array;
+ *   final int lo, hi;
+ *   double result;
+ *   Applyer next; // keeps track of right-hand-side tasks
+ *   Applyer(double[] array, int lo, int hi, Applyer next) {
+ *     this.array = array; this.lo = lo; this.hi = hi;
+ *     this.next = next;
+ *   }
+ *
+ *   double atLeaf(int l, int h) {
+ *     double sum = 0;
+ *     for (int i = l; i < h; ++i) // perform leftmost base step
+ *       sum += array[i] * array[i];
+ *     return sum;
+ *   }
+ *
+ *   protected void compute() {
+ *     int l = lo;
+ *     int h = hi;
+ *     Applyer right = null;
+ *     while (h - l > 1 && getSurplusQueuedTaskCount() <= 3) {
+ *        int mid = (l + h) >>> 1;
+ *        right = new Applyer(array, mid, h, right);
+ *        right.fork();
+ *        h = mid;
+ *     }
+ *     double sum = atLeaf(l, h);
+ *     while (right != null) {
+ *        if (right.tryUnfork()) // directly calculate if not stolen
+ *          sum += right.atLeaf(right.lo, right.hi);
+ *       else {
+ *          right.helpJoin();
+ *          sum += right.result;
+ *        }
+ *        right = right.next;
+ *      }
+ *     result = sum;
+ *   }
+ * }}</pre>
+ *
+ * @since 1.7
+ * @author Doug Lea
+ */
+public abstract class RecursiveAction extends ForkJoinTask<Void> {
+    private static final long serialVersionUID = 5232453952276485070L;
+
+    /**
+     * The main computation performed by this task.
+     */
+    protected abstract void compute();
+
+    /**
+     * Always returns null.
+     */
+    public final Void getRawResult() { return null; }
+
+    /**
+     * Requires null completion value.
+     */
+    protected final void setRawResult(Void mustBeNull) { }
+
+    /**
+     * Implements execution conventions for RecursiveActions.
+     */
+    protected final boolean exec() {
+        compute();
+        return true;
+    }
+
+}

jdk/src/share/classes/java/util/concurrent/RecursiveTask.java

@@ -0,0 +1,97 @@
+/*
+ * 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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * 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
+ */
+
+package java.util.concurrent;
+
+/**
+ * A recursive result-bearing {@link ForkJoinTask}.
+ *
+ * <p>For a classic example, here is a task computing Fibonacci numbers:
+ *
+ *  <pre> {@code
+ * class Fibonacci extends RecursiveTask<Integer> {
+ *   final int n;
+ *   Fibonacci(int n) { this.n = n; }
+ *   Integer compute() {
+ *     if (n <= 1)
+ *        return n;
+ *     Fibonacci f1 = new Fibonacci(n - 1);
+ *     f1.fork();
+ *     Fibonacci f2 = new Fibonacci(n - 2);
+ *     return f2.compute() + f1.join();
+ *   }
+ * }}</pre>
+ *
+ * However, besides being a dumb way to compute Fibonacci functions
+ * (there is a simple fast linear algorithm that you'd use in
+ * practice), this is likely to perform poorly because the smallest
+ * subtasks are too small to be worthwhile splitting up. Instead, as
+ * is the case for nearly all fork/join applications, you'd pick some
+ * minimum granularity size (for example 10 here) for which you always
+ * sequentially solve rather than subdividing.
+ *
+ * @since 1.7
+ * @author Doug Lea
+ */
+public abstract class RecursiveTask<V> extends ForkJoinTask<V> {
+    private static final long serialVersionUID = 5232453952276485270L;
+
+    /**
+     * The result of the computation.
+     */
+    V result;
+
+    /**
+     * The main computation performed by this task.
+     */
+    protected abstract V compute();
+
+    public final V getRawResult() {
+        return result;
+    }
+
+    protected final void setRawResult(V value) {
+        result = value;
+    }
+
+    /**
+     * Implements execution conventions for RecursiveTask.
+     */
+    protected final boolean exec() {
+        result = compute();
+        return true;
+    }
+
+}

jdk/src/share/classes/java/util/concurrent/ScheduledThreadPoolExecutor.java

@@ -61,6 +61,14 @@ import java.util.*;
  * causes tasks to be immediately removed from the work queue at
  * time of cancellation.
  *
+ * <p>Successive executions of a task scheduled via
+ * <code>scheduleAtFixedRate</code> or
+ * <code>scheduleWithFixedDelay</code> do not overlap. While different
+ * executions may be performed by different threads, the effects of
+ * prior executions <a
+ * href="package-summary.html#MemoryVisibility"><i>happen-before</i></a>
+ * those of subsequent ones.
+ *
  * <p>While this class inherits from {@link ThreadPoolExecutor}, a few
  * of the inherited tuning methods are not useful for it. In
  * particular, because it acts as a fixed-sized pool using

jdk/src/share/classes/java/util/concurrent/ThreadLocalRandom.java

@@ -0,0 +1,228 @@
+/*
+ * 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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * 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
+ */
+
+package java.util.concurrent;
+
+import java.util.Random;
+
+/**
+ * A random number generator isolated to the current thread.  Like the
+ * global {@link java.util.Random} generator used by the {@link
+ * java.lang.Math} class, a {@code ThreadLocalRandom} is initialized
+ * with an internally generated seed that may not otherwise be
+ * modified. When applicable, use of {@code ThreadLocalRandom} rather
+ * than shared {@code Random} objects in concurrent programs will
+ * typically encounter much less overhead and contention.  Use of
+ * {@code ThreadLocalRandom} is particularly appropriate when multiple
+ * tasks (for example, each a {@link ForkJoinTask}) use random numbers
+ * in parallel in thread pools.
+ *
+ * <p>Usages of this class should typically be of the form:
+ * {@code ThreadLocalRandom.current().nextX(...)} (where
+ * {@code X} is {@code Int}, {@code Long}, etc).
+ * When all usages are of this form, it is never possible to
+ * accidently share a {@code ThreadLocalRandom} across multiple threads.
+ *
+ * <p>This class also provides additional commonly used bounded random
+ * generation methods.
+ *
+ * @since 1.7
+ * @author Doug Lea
+ */
+public class ThreadLocalRandom extends Random {
+    // same constants as Random, but must be redeclared because private
+    private final static long multiplier = 0x5DEECE66DL;
+    private final static long addend = 0xBL;
+    private final static long mask = (1L << 48) - 1;
+
+    /**
+     * The random seed. We can't use super.seed.
+     */
+    private long rnd;
+
+    /**
+     * Initialization flag to permit the first and only allowed call
+     * to setSeed (inside Random constructor) to succeed.  We can't
+     * allow others since it would cause setting seed in one part of a
+     * program to unintentionally impact other usages by the thread.
+     */
+    boolean initialized;
+
+    // Padding to help avoid memory contention among seed updates in
+    // different TLRs in the common case that they are located near
+    // each other.
+    private long pad0, pad1, pad2, pad3, pad4, pad5, pad6, pad7;
+
+    /**
+     * The actual ThreadLocal
+     */
+    private static final ThreadLocal<ThreadLocalRandom> localRandom =
+        new ThreadLocal<ThreadLocalRandom>() {
+            protected ThreadLocalRandom initialValue() {
+                return new ThreadLocalRandom();
+            }
+    };
+
+
+    /**
+     * Constructor called only by localRandom.initialValue.
+     * We rely on the fact that the superclass no-arg constructor
+     * invokes setSeed exactly once to initialize.
+     */
+    ThreadLocalRandom() {
+        super();
+    }
+
+    /**
+     * Returns the current thread's {@code ThreadLocalRandom}.
+     *
+     * @return the current thread's {@code ThreadLocalRandom}
+     */
+    public static ThreadLocalRandom current() {
+        return localRandom.get();
+    }
+
+    /**
+     * Throws {@code UnsupportedOperationException}.  Setting seeds in
+     * this generator is not supported.
+     *
+     * @throws UnsupportedOperationException always
+     */
+    public void setSeed(long seed) {
+        if (initialized)
+            throw new UnsupportedOperationException();
+        initialized = true;
+        rnd = (seed ^ multiplier) & mask;
+    }
+
+    protected int next(int bits) {
+        rnd = (rnd * multiplier + addend) & mask;
+        return (int) (rnd >>> (48-bits));
+    }
+
+    /**
+     * Returns a pseudorandom, uniformly distributed value between the
+     * given least value (inclusive) and bound (exclusive).
+     *
+     * @param least the least value returned
+     * @param bound the upper bound (exclusive)
+     * @throws IllegalArgumentException if least greater than or equal
+     * to bound
+     * @return the next value
+     */
+    public int nextInt(int least, int bound) {
+        if (least >= bound)
+            throw new IllegalArgumentException();
+        return nextInt(bound - least) + least;
+    }
+
+    /**
+     * Returns a pseudorandom, uniformly distributed value
+     * between 0 (inclusive) and the specified value (exclusive).
+     *
+     * @param n the bound on the random number to be returned.  Must be
+     *        positive.
+     * @return the next value
+     * @throws IllegalArgumentException if n is not positive
+     */
+    public long nextLong(long n) {
+        if (n <= 0)
+            throw new IllegalArgumentException("n must be positive");
+        // Divide n by two until small enough for nextInt. On each
+        // iteration (at most 31 of them but usually much less),
+        // randomly choose both whether to include high bit in result
+        // (offset) and whether to continue with the lower vs upper
+        // half (which makes a difference only if odd).
+        long offset = 0;
+        while (n >= Integer.MAX_VALUE) {
+            int bits = next(2);
+            long half = n >>> 1;
+            long nextn = ((bits & 2) == 0) ? half : n - half;
+            if ((bits & 1) == 0)
+                offset += n - nextn;
+            n = nextn;
+        }
+        return offset + nextInt((int) n);
+    }
+
+    /**
+     * Returns a pseudorandom, uniformly distributed value between the
+     * given least value (inclusive) and bound (exclusive).
+     *
+     * @param least the least value returned
+     * @param bound the upper bound (exclusive)
+     * @return the next value
+     * @throws IllegalArgumentException if least greater than or equal
+     * to bound
+     */
+    public long nextLong(long least, long bound) {
+        if (least >= bound)
+            throw new IllegalArgumentException();
+        return nextLong(bound - least) + least;
+    }
+
+    /**
+     * Returns a pseudorandom, uniformly distributed {@code double} value
+     * between 0 (inclusive) and the specified value (exclusive).
+     *
+     * @param n the bound on the random number to be returned.  Must be
+     *        positive.
+     * @return the next value
+     * @throws IllegalArgumentException if n is not positive
+     */
+    public double nextDouble(double n) {
+        if (n <= 0)
+            throw new IllegalArgumentException("n must be positive");
+        return nextDouble() * n;
+    }
+
+    /**
+     * Returns a pseudorandom, uniformly distributed value between the
+     * given least value (inclusive) and bound (exclusive).
+     *
+     * @param least the least value returned
+     * @param bound the upper bound (exclusive)
+     * @return the next value
+     * @throws IllegalArgumentException if least greater than or equal
+     * to bound
+     */
+    public double nextDouble(double least, double bound) {
+        if (least >= bound)
+            throw new IllegalArgumentException();
+        return nextDouble() * (bound - least) + least;
+    }
+
+    private static final long serialVersionUID = -5851777807851030925L;
+}

jdk/src/share/classes/java/util/concurrent/TransferQueue.java

@@ -0,0 +1,161 @@
+/*
+ * 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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * 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
+ */
+
+package java.util.concurrent;
+
+/**
+ * A {@link BlockingQueue} in which producers may wait for consumers
+ * to receive elements.  A {@code TransferQueue} may be useful for
+ * example in message passing applications in which producers
+ * sometimes (using method {@link #transfer}) await receipt of
+ * elements by consumers invoking {@code take} or {@code poll}, while
+ * at other times enqueue elements (via method {@code put}) without
+ * waiting for receipt.
+ * {@linkplain #tryTransfer(Object) Non-blocking} and
+ * {@linkplain #tryTransfer(Object,long,TimeUnit) time-out} versions of
+ * {@code tryTransfer} are also available.
+ * A {@code TransferQueue} may also be queried, via {@link
+ * #hasWaitingConsumer}, whether there are any threads waiting for
+ * items, which is a converse analogy to a {@code peek} operation.
+ *
+ * <p>Like other blocking queues, a {@code TransferQueue} may be
+ * capacity bounded.  If so, an attempted transfer operation may
+ * initially block waiting for available space, and/or subsequently
+ * block waiting for reception by a consumer.  Note that in a queue
+ * with zero capacity, such as {@link SynchronousQueue}, {@code put}
+ * and {@code transfer} are effectively synonymous.
+ *
+ * <p>This interface is a member of the
+ * <a href="{@docRoot}/../technotes/guides/collections/index.html">
+ * Java Collections Framework</a>.
+ *
+ * @since 1.7
+ * @author Doug Lea
+ * @param <E> the type of elements held in this collection
+ */
+public interface TransferQueue<E> extends BlockingQueue<E> {
+    /**
+     * Transfers the element to a waiting consumer immediately, if possible.
+     *
+     * <p>More precisely, transfers the specified element immediately
+     * if there exists a consumer already waiting to receive it (in
+     * {@link #take} or timed {@link #poll(long,TimeUnit) poll}),
+     * otherwise returning {@code false} without enqueuing the element.
+     *
+     * @param e the element to transfer
+     * @return {@code true} if the element was transferred, else
+     *         {@code false}
+     * @throws ClassCastException if the class of the specified element
+     *         prevents it from being added to this queue
+     * @throws NullPointerException if the specified element is null
+     * @throws IllegalArgumentException if some property of the specified
+     *         element prevents it from being added to this queue
+     */
+    boolean tryTransfer(E e);
+
+    /**
+     * Transfers the element to a consumer, waiting if necessary to do so.
+     *
+     * <p>More precisely, transfers the specified element immediately
+     * if there exists a consumer already waiting to receive it (in
+     * {@link #take} or timed {@link #poll(long,TimeUnit) poll}),
+     * else waits until the element is received by a consumer.
+     *
+     * @param e the element to transfer
+     * @throws InterruptedException if interrupted while waiting,
+     *         in which case the element is not left enqueued
+     * @throws ClassCastException if the class of the specified element
+     *         prevents it from being added to this queue
+     * @throws NullPointerException if the specified element is null
+     * @throws IllegalArgumentException if some property of the specified
+     *         element prevents it from being added to this queue
+     */
+    void transfer(E e) throws InterruptedException;
+
+    /**
+     * Transfers the element to a consumer if it is possible to do so
+     * before the timeout elapses.
+     *
+     * <p>More precisely, transfers the specified element immediately
+     * if there exists a consumer already waiting to receive it (in
+     * {@link #take} or timed {@link #poll(long,TimeUnit) poll}),
+     * else waits until the element is received by a consumer,
+     * returning {@code false} if the specified wait time elapses
+     * before the element can be transferred.
+     *
+     * @param e the element to transfer
+     * @param timeout how long to wait before giving up, in units of
+     *        {@code unit}
+     * @param unit a {@code TimeUnit} determining how to interpret the
+     *        {@code timeout} parameter
+     * @return {@code true} if successful, or {@code false} if
+     *         the specified waiting time elapses before completion,
+     *         in which case the element is not left enqueued
+     * @throws InterruptedException if interrupted while waiting,
+     *         in which case the element is not left enqueued
+     * @throws ClassCastException if the class of the specified element
+     *         prevents it from being added to this queue
+     * @throws NullPointerException if the specified element is null
+     * @throws IllegalArgumentException if some property of the specified
+     *         element prevents it from being added to this queue
+     */
+    boolean tryTransfer(E e, long timeout, TimeUnit unit)
+        throws InterruptedException;
+
+    /**
+     * Returns {@code true} if there is at least one consumer waiting
+     * to receive an element via {@link #take} or
+     * timed {@link #poll(long,TimeUnit) poll}.
+     * The return value represents a momentary state of affairs.
+     *
+     * @return {@code true} if there is at least one waiting consumer
+     */
+    boolean hasWaitingConsumer();
+
+    /**
+     * Returns an estimate of the number of consumers waiting to
+     * receive elements via {@link #take} or timed
+     * {@link #poll(long,TimeUnit) poll}.  The return value is an
+     * approximation of a momentary state of affairs, that may be
+     * inaccurate if consumers have completed or given up waiting.
+     * The value may be useful for monitoring and heuristics, but
+     * not for synchronization control.  Implementations of this
+     * method are likely to be noticeably slower than those for
+     * {@link #hasWaitingConsumer}.
+     *
+     * @return the number of consumers waiting to receive elements
+     */
+    int getWaitingConsumerCount();
+}

jdk/src/share/classes/java/util/concurrent/locks/Condition.java

@@ -170,8 +170,8 @@ import java.util.Date;
  * <p>As interruption generally implies cancellation, and checks for
  * interruption are often infrequent, an implementation can favor responding
  * to an interrupt over normal method return. This is true even if it can be
- * shown that the interrupt occurred after another action may have unblocked
- * the thread. An implementation should document this behavior.
+ * shown that the interrupt occurred after another action that may have
+ * unblocked the thread. An implementation should document this behavior.
  *
  * @since 1.5
  * @author Doug Lea

jdk/src/share/classes/java/util/concurrent/package-info.java

@@ -92,6 +92,13 @@
  * assists in coordinating the processing of groups of
  * asynchronous tasks.
  *
+ * <p>Class {@link java.util.concurrent.ForkJoinPool} provides an
+ * Executor primarily designed for processing instances of {@link
+ * java.util.concurrent.ForkJoinTask} and its subclasses.  These
+ * classes employ a work-stealing scheduler that attains high
+ * throughput for tasks conforming to restrictions that often hold in
+ * computation-intensive parallel processing.
+ *
  * <h2>Queues</h2>
  *
  * The {@link java.util.concurrent.ConcurrentLinkedQueue} class
@@ -110,6 +117,12 @@
  * for producer-consumer, messaging, parallel tasking, and
  * related concurrent designs.
  *
+ * <p> Extended interface {@link java.util.concurrent.TransferQueue},
+ * and implementation {@link java.util.concurrent.LinkedTransferQueue}
+ * introduce a synchronous {@code transfer} method (along with related
+ * features) in which a producer may optionally block awaiting its
+ * consumer.
+ *
  * <p>The {@link java.util.concurrent.BlockingDeque} interface
  * extends {@code BlockingQueue} to support both FIFO and LIFO
  * (stack-based) operations.
@@ -136,15 +149,28 @@
  *
  * <h2>Synchronizers</h2>
  *
- * Four classes aid common special-purpose synchronization idioms.
- * {@link java.util.concurrent.Semaphore} is a classic concurrency tool.
- * {@link java.util.concurrent.CountDownLatch} is a very simple yet very
- * common utility for blocking until a given number of signals, events,
- * or conditions hold.  A {@link java.util.concurrent.CyclicBarrier} is a
- * resettable multiway synchronization point useful in some styles of
- * parallel programming.  An {@link java.util.concurrent.Exchanger} allows
- * two threads to exchange objects at a rendezvous point, and is useful
- * in several pipeline designs.
+ * Five classes aid common special-purpose synchronization idioms.
+ * <ul>
+ *
+ * <li>{@link java.util.concurrent.Semaphore} is a classic concurrency tool.
+ *
+ * <li>{@link java.util.concurrent.CountDownLatch} is a very simple yet
+ * very common utility for blocking until a given number of signals,
+ * events, or conditions hold.
+ *
+ * <li>A {@link java.util.concurrent.CyclicBarrier} is a resettable
+ * multiway synchronization point useful in some styles of parallel
+ * programming.
+ *
+ * <li>A {@link java.util.concurrent.Phaser} provides
+ * a more flexible form of barrier that may be used to control phased
+ * computation among multiple threads.
+ *
+ * <li>An {@link java.util.concurrent.Exchanger} allows two threads to
+ * exchange objects at a rendezvous point, and is useful in several
+ * pipeline designs.
+ *
+ * </ul>
  *
  * <h2>Concurrent Collections</h2>
  *
@@ -259,7 +285,8 @@
  *   in each thread <i>happen-before</i> those subsequent to the
  *   corresponding {@code exchange()} in another thread.
  *
- *   <li>Actions prior to calling {@code CyclicBarrier.await}
+ *   <li>Actions prior to calling {@code CyclicBarrier.await} and
+ *   {@code Phaser.awaitAdvance} (as well as its variants)
  *   <i>happen-before</i> actions performed by the barrier action, and
  *   actions performed by the barrier action <i>happen-before</i> actions
  *   subsequent to a successful return from the corresponding {@code await}

jdk/test/java/util/Collection/BiggernYours.java

@@ -178,10 +178,10 @@ public class BiggernYours {
             new ConcurrentLinkedQueue() {
                 public int size() {return randomize(super.size());}});
 
-//         testCollections(
-//             new LinkedTransferQueue(),
-//             new LinkedTransferQueue() {
-//                 public int size() {return randomize(super.size());}});
+        testCollections(
+            new LinkedTransferQueue(),
+            new LinkedTransferQueue() {
+                public int size() {return randomize(super.size());}});
 
         testCollections(
             new LinkedBlockingQueue(),

jdk/test/java/util/Collection/IteratorAtEnd.java

@@ -49,7 +49,7 @@ public class IteratorAtEnd {
         testCollection(new LinkedBlockingQueue());
         testCollection(new ArrayBlockingQueue(100));
         testCollection(new ConcurrentLinkedQueue());
-//         testCollection(new LinkedTransferQueue());
+        testCollection(new LinkedTransferQueue());
 
         testMap(new HashMap());
         testMap(new Hashtable());

jdk/test/java/util/Collection/MOAT.java

@@ -76,7 +76,7 @@ public class MOAT {
         testCollection(new LinkedBlockingQueue<Integer>(20));
         testCollection(new LinkedBlockingDeque<Integer>(20));
         testCollection(new ConcurrentLinkedQueue<Integer>());
-//         testCollection(new LinkedTransferQueue<Integer>());
+        testCollection(new LinkedTransferQueue<Integer>());
         testCollection(new ConcurrentSkipListSet<Integer>());
         testCollection(Arrays.asList(new Integer(42)));
         testCollection(Arrays.asList(1,2,3));

jdk/test/java/util/Collections/CheckedNull.java

@@ -52,7 +52,7 @@ public class CheckedNull {
 
         testMap(Collections.checkedMap(
                     new HashMap<String, String>(),
-                    String.class, String.class));;
+                    String.class, String.class));
     }
 
     ClassCastException cce(F f) {

jdk/test/java/util/Collections/RacingCollections.java

@@ -234,7 +234,7 @@ public class RacingCollections {
         List<Queue<Integer>> list =
             new ArrayList<Queue<Integer>>(newConcurrentDeques());
         list.add(new LinkedBlockingQueue<Integer>(10));
-//         list.add(new LinkedTransferQueue<Integer>());
+        list.add(new LinkedTransferQueue<Integer>());
         return list;
     }
 

jdk/test/java/util/PriorityQueue/RemoveContains.java

@@ -69,7 +69,7 @@ public class RemoveContains {
         test(new ArrayBlockingQueue<String>(10));
         test(new LinkedBlockingQueue<String>(10));
         test(new LinkedBlockingDeque<String>(10));
-//         test(new LinkedTransferQueue<String>());
+        test(new LinkedTransferQueue<String>());
         test(new ArrayDeque<String>(10));
 
         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);

jdk/test/java/util/concurrent/BlockingQueue/CancelledProducerConsumerLoops.java

@@ -119,12 +119,36 @@ public class CancelledProducerConsumerLoops {
         }
     }
 
+    static final class LTQasSQ<T> extends LinkedTransferQueue<T> {
+        LTQasSQ() { super(); }
+        public void put(T x) {
+            try { super.transfer(x); }
+            catch (InterruptedException ex) { throw new Error(); }
+        }
+        private final static long serialVersionUID = 42;
+    }
+
+    static final class HalfSyncLTQ<T> extends LinkedTransferQueue<T> {
+        HalfSyncLTQ() { super(); }
+        public void put(T x) {
+            if (ThreadLocalRandom.current().nextBoolean())
+                super.put(x);
+            else {
+                try { super.transfer(x); }
+                catch (InterruptedException ex) { throw new Error(); }
+            }
+        }
+        private final static long serialVersionUID = 42;
+    }
+
     static void oneTest(int pairs, int iters) throws Exception {
 
         oneRun(new ArrayBlockingQueue<Integer>(CAPACITY), pairs, iters);
         oneRun(new LinkedBlockingQueue<Integer>(CAPACITY), pairs, iters);
         oneRun(new LinkedBlockingDeque<Integer>(CAPACITY), pairs, iters);
-//         oneRun(new LinkedTransferQueue<Integer>(), pairs, iters);
+        oneRun(new LinkedTransferQueue<Integer>(), pairs, iters);
+        oneRun(new LTQasSQ<Integer>(), pairs, iters);
+        oneRun(new HalfSyncLTQ<Integer>(), pairs, iters);
         oneRun(new SynchronousQueue<Integer>(), pairs, iters / 8);
 
         /* PriorityBlockingQueue is unbounded

jdk/test/java/util/concurrent/BlockingQueue/LastElement.java

@@ -37,7 +37,7 @@ public class LastElement {
         testQueue(new LinkedBlockingDeque<Integer>());
         testQueue(new ArrayBlockingQueue<Integer>(10, true));
         testQueue(new ArrayBlockingQueue<Integer>(10, false));
-//         testQueue(new LinkedTransferQueue<Integer>());
+        testQueue(new LinkedTransferQueue<Integer>());
 
         System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
         if (failed > 0) throw new Exception("Some tests failed");

jdk/test/java/util/concurrent/BlockingQueue/MultipleProducersSingleConsumerLoops.java

@@ -87,11 +87,35 @@ public class MultipleProducersSingleConsumerLoops {
             throw new Error();
    }
 
+    static final class LTQasSQ<T> extends LinkedTransferQueue<T> {
+        LTQasSQ() { super(); }
+        public void put(T x) {
+            try { super.transfer(x); }
+            catch (InterruptedException ex) { throw new Error(); }
+        }
+        private final static long serialVersionUID = 42;
+    }
+
+    static final class HalfSyncLTQ<T> extends LinkedTransferQueue<T> {
+        HalfSyncLTQ() { super(); }
+        public void put(T x) {
+            if (ThreadLocalRandom.current().nextBoolean())
+                super.put(x);
+            else {
+                try { super.transfer(x); }
+                catch (InterruptedException ex) { throw new Error(); }
+            }
+        }
+        private final static long serialVersionUID = 42;
+    }
+
     static void oneTest(int producers, int iters) throws Exception {
         oneRun(new ArrayBlockingQueue<Integer>(CAPACITY), producers, iters);
         oneRun(new LinkedBlockingQueue<Integer>(CAPACITY), producers, iters);
         oneRun(new LinkedBlockingDeque<Integer>(CAPACITY), producers, iters);
-//         oneRun(new LinkedTransferQueue<Integer>(), producers, iters);
+        oneRun(new LinkedTransferQueue<Integer>(), producers, iters);
+        oneRun(new LTQasSQ<Integer>(), producers, iters);
+        oneRun(new HalfSyncLTQ<Integer>(), producers, iters);
 
         // Don't run PBQ since can legitimately run out of memory
         //        if (print)

jdk/test/java/util/concurrent/BlockingQueue/OfferDrainToLoops.java

@@ -63,12 +63,11 @@ public class OfferDrainToLoops {
         test(new LinkedBlockingDeque());
         test(new LinkedBlockingDeque(2000));
         test(new ArrayBlockingQueue(2000));
-//         test(new LinkedTransferQueue());
+        test(new LinkedTransferQueue());
     }
 
     Random getRandom() {
-        return new Random();
-        // return ThreadLocalRandom.current();
+        return ThreadLocalRandom.current();
     }
 
     void test(final BlockingQueue q) throws Throwable {

jdk/test/java/util/concurrent/BlockingQueue/PollMemoryLeak.java

@@ -46,7 +46,7 @@ public class PollMemoryLeak {
     public static void main(String[] args) throws InterruptedException {
         final BlockingQueue[] qs = {
             new LinkedBlockingQueue(10),
-//             new LinkedTransferQueue(),
+            new LinkedTransferQueue(),
             new ArrayBlockingQueue(10),
             new SynchronousQueue(),
             new SynchronousQueue(true),

jdk/test/java/util/concurrent/BlockingQueue/ProducerConsumerLoops.java

@@ -87,11 +87,35 @@ public class ProducerConsumerLoops {
             throw new Error();
    }
 
+    static final class LTQasSQ<T> extends LinkedTransferQueue<T> {
+        LTQasSQ() { super(); }
+        public void put(T x) {
+            try { super.transfer(x); }
+            catch (InterruptedException ex) { throw new Error(); }
+        }
+        private final static long serialVersionUID = 42;
+    }
+
+    static final class HalfSyncLTQ<T> extends LinkedTransferQueue<T> {
+        HalfSyncLTQ() { super(); }
+        public void put(T x) {
+            if (ThreadLocalRandom.current().nextBoolean())
+                super.put(x);
+            else {
+                try { super.transfer(x); }
+                catch (InterruptedException ex) { throw new Error(); }
+            }
+        }
+        private final static long serialVersionUID = 42;
+    }
+
     static void oneTest(int pairs, int iters) throws Exception {
         oneRun(new ArrayBlockingQueue<Integer>(CAPACITY), pairs, iters);
         oneRun(new LinkedBlockingQueue<Integer>(CAPACITY), pairs, iters);
         oneRun(new LinkedBlockingDeque<Integer>(CAPACITY), pairs, iters);
-//         oneRun(new LinkedTransferQueue<Integer>(), pairs, iters);
+        oneRun(new LinkedTransferQueue<Integer>(), pairs, iters);
+        oneRun(new LTQasSQ<Integer>(), pairs, iters);
+        oneRun(new HalfSyncLTQ<Integer>(), pairs, iters);
         oneRun(new PriorityBlockingQueue<Integer>(), pairs, iters);
         oneRun(new SynchronousQueue<Integer>(), pairs, iters);
 

jdk/test/java/util/concurrent/BlockingQueue/SingleProducerMultipleConsumerLoops.java

@@ -73,11 +73,35 @@ public class SingleProducerMultipleConsumerLoops {
             throw new Error();
    }
 
+    static final class LTQasSQ<T> extends LinkedTransferQueue<T> {
+        LTQasSQ() { super(); }
+        public void put(T x) {
+            try { super.transfer(x); }
+            catch (InterruptedException ex) { throw new Error(); }
+        }
+        private final static long serialVersionUID = 42;
+    }
+
+    static final class HalfSyncLTQ<T> extends LinkedTransferQueue<T> {
+        HalfSyncLTQ() { super(); }
+        public void put(T x) {
+            if (ThreadLocalRandom.current().nextBoolean())
+                super.put(x);
+            else {
+                try { super.transfer(x); }
+                catch (InterruptedException ex) { throw new Error(); }
+            }
+        }
+        private final static long serialVersionUID = 42;
+    }
+
     static void oneTest(int consumers, int iters) throws Exception {
         oneRun(new ArrayBlockingQueue<Integer>(CAPACITY), consumers, iters);
         oneRun(new LinkedBlockingQueue<Integer>(CAPACITY), consumers, iters);
         oneRun(new LinkedBlockingDeque<Integer>(CAPACITY), consumers, iters);
-//         oneRun(new LinkedTransferQueue<Integer>(), consumers, iters);
+        oneRun(new LinkedTransferQueue<Integer>(), consumers, iters);
+        oneRun(new LTQasSQ<Integer>(), consumers, iters);
+        oneRun(new HalfSyncLTQ<Integer>(), consumers, iters);
         oneRun(new PriorityBlockingQueue<Integer>(), consumers, iters);
         oneRun(new SynchronousQueue<Integer>(), consumers, iters);
         if (print)

jdk/test/java/util/concurrent/ConcurrentQueues/ConcurrentQueueLoops.java

@@ -60,7 +60,7 @@ public class ConcurrentQueueLoops {
         //queues.add(new ArrayBlockingQueue<Integer>(count, true));
         queues.add(new LinkedBlockingQueue<Integer>());
         queues.add(new LinkedBlockingDeque<Integer>());
-//         queues.add(new LinkedTransferQueue<Integer>());
+        queues.add(new LinkedTransferQueue<Integer>());
 
         // Following additional implementations are available from:
         // http://gee.cs.oswego.edu/dl/concurrency-interest/index.html

jdk/test/java/util/concurrent/ConcurrentQueues/GCRetention.java

@@ -43,7 +43,7 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.LinkedBlockingDeque;
 import java.util.concurrent.LinkedBlockingQueue;
-// import java.util.concurrent.LinkedTransferQueue;
+import java.util.concurrent.LinkedTransferQueue;
 import java.util.concurrent.PriorityBlockingQueue;
 import java.util.LinkedList;
 import java.util.PriorityQueue;
@@ -70,7 +70,7 @@ public class GCRetention {
         queues.add(new PriorityBlockingQueue<Boolean>());
         queues.add(new PriorityQueue<Boolean>());
         queues.add(new LinkedList<Boolean>());
-//         queues.add(new LinkedTransferQueue<Boolean>());
+        queues.add(new LinkedTransferQueue<Boolean>());
 
         // Following additional implementations are available from:
         // http://gee.cs.oswego.edu/dl/concurrency-interest/index.html

jdk/test/java/util/concurrent/ConcurrentQueues/IteratorWeakConsistency.java

@@ -49,7 +49,7 @@ public class IteratorWeakConsistency {
         test(new LinkedBlockingDeque());
         test(new LinkedBlockingDeque(20));
         test(new ConcurrentLinkedQueue());
-//         test(new LinkedTransferQueue());
+        test(new LinkedTransferQueue());
         // Other concurrent queues (e.g. ArrayBlockingQueue) do not
         // currently have weakly consistent iterators.
         // test(new ArrayBlockingQueue(20));

jdk/test/java/util/concurrent/ConcurrentQueues/OfferRemoveLoops.java

@@ -56,12 +56,11 @@ public class OfferRemoveLoops {
         testQueue(new ArrayBlockingQueue(10));
         testQueue(new PriorityBlockingQueue(10));
         testQueue(new ConcurrentLinkedQueue());
-//         testQueue(new LinkedTransferQueue());
+        testQueue(new LinkedTransferQueue());
     }
 
     Random getRandom() {
-        return new Random();
-        // return ThreadLocalRandom.current();
+        return ThreadLocalRandom.current();
     }
 
     void testQueue(final Queue q) throws Throwable {

jdk/test/java/util/concurrent/ConcurrentQueues/RemovePollRace.java

@@ -45,7 +45,7 @@ import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.LinkedBlockingDeque;
 import java.util.concurrent.LinkedBlockingQueue;
-// import java.util.concurrent.LinkedTransferQueue;
+import java.util.concurrent.LinkedTransferQueue;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -67,7 +67,7 @@ public class RemovePollRace {
         queues.add(new ArrayBlockingQueue<Boolean>(count, true));
         queues.add(new LinkedBlockingQueue<Boolean>());
         queues.add(new LinkedBlockingDeque<Boolean>());
-//         queues.add(new LinkedTransferQueue<Boolean>());
+        queues.add(new LinkedTransferQueue<Boolean>());
 
         // Following additional implementations are available from:
         // http://gee.cs.oswego.edu/dl/concurrency-interest/index.html

jdk/test/java/util/concurrent/Phaser/Arrive.java

@@ -0,0 +1,94 @@
+/*
+ * 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 6445158
+ * @summary tests for Phaser.arrive()
+ */
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Phaser;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class Arrive {
+    void test(String[] args) throws Throwable {
+        final int n = ThreadLocalRandom.current().nextInt(1, 10);
+        final int nthreads = n*3/2;
+        final Phaser startingGate = new Phaser(nthreads);
+        final Phaser phaser = new Phaser(n);
+        final List<Thread> threads = new ArrayList<Thread>();
+        final AtomicInteger count0 = new AtomicInteger(0);
+        final AtomicInteger count1 = new AtomicInteger(0);
+        final Runnable task = new Runnable() { public void run() {
+            equal(startingGate.getPhase(), 0);
+            startingGate.arriveAndAwaitAdvance();
+            equal(startingGate.getPhase(), 1);
+            int phase = phaser.arrive();
+            if (phase == 0)
+                count0.getAndIncrement();
+            else if (phase == 1)
+                count1.getAndIncrement();
+            else
+                fail();
+        }};
+        for (int i = 0; i < nthreads; i++)
+            threads.add(new Thread(task));
+        for (Thread thread : threads)
+            thread.start();
+        for (Thread thread : threads)
+            thread.join();
+        equal(count0.get(), n);
+        equal(count1.get(), nthreads-n);
+        equal(phaser.getPhase(), 1);
+    }
+
+    //--------------------- Infrastructure ---------------------------
+    volatile int passed = 0, failed = 0;
+    void pass() {passed++;}
+    void fail() {failed++; Thread.dumpStack();}
+    void fail(String msg) {System.err.println(msg); fail();}
+    void unexpected(Throwable t) {failed++; t.printStackTrace();}
+    void check(boolean cond) {if (cond) pass(); else fail();}
+    void equal(Object x, Object y) {
+        if (x == null ? y == null : x.equals(y)) pass();
+        else fail(x + " not equal to " + y);}
+    public static void main(String[] args) throws Throwable {
+        new Arrive().instanceMain(args);}
+    public void instanceMain(String[] args) throws Throwable {
+        try {test(args);} catch (Throwable t) {unexpected(t);}
+        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
+        if (failed > 0) throw new AssertionError("Some tests failed");}
+}

jdk/test/java/util/concurrent/Phaser/Basic.java

@@ -0,0 +1,407 @@
+/*
+ * 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 6445158
+ * @summary Basic tests for Phaser
+ * @author Chris Hegarty
+ */
+
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.concurrent.Phaser;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicInteger;
+import static java.util.concurrent.TimeUnit.*;
+
+public class Basic {
+
+    private static void checkTerminated(final Phaser phaser) {
+        check(phaser.isTerminated());
+        int unarriverParties = phaser.getUnarrivedParties();
+        int registeredParties = phaser.getRegisteredParties();
+        equal(phaser.arrive(), -1);
+        equal(phaser.arriveAndDeregister(), -1);
+        equal(phaser.arriveAndAwaitAdvance(), -1);
+        equal(phaser.bulkRegister(10), -1);
+        equal(phaser.getPhase(), -1);
+        equal(phaser.register(), -1);
+        try {
+            equal(phaser.awaitAdvanceInterruptibly(0), -1);
+            equal(phaser.awaitAdvanceInterruptibly(0, 10, SECONDS), -1);
+        } catch (Exception ie) {
+            unexpected(ie);
+        }
+        equal(phaser.getUnarrivedParties(), unarriverParties);
+        equal(phaser.getRegisteredParties(), registeredParties);
+    }
+
+    private static void checkResult(Arriver a, Class<? extends Throwable> c) {
+        Throwable t = a.result();
+        if (! ((t == null && c == null) || (c != null && c.isInstance(t)))) {
+            //      t.printStackTrace();
+            fail("Mismatch in thread " +
+                 a.getName() + ": " +
+                 t + ", " +
+                 (c == null ? "<null>" : c.getName()));
+        } else {
+            pass();
+        }
+    }
+
+    //----------------------------------------------------------------
+    // Mechanism to get all test threads into "running" mode.
+    //----------------------------------------------------------------
+    private static Phaser atTheStartingGate = new Phaser(3);
+
+    private static void toTheStartingGate() {
+        try {
+            boolean expectNextPhase = false;
+            if (atTheStartingGate.getUnarrivedParties() == 1) {
+                expectNextPhase = true;
+            }
+            int phase = atTheStartingGate.getPhase();
+            equal(phase, atTheStartingGate.arrive());
+            int AwaitPhase = atTheStartingGate.awaitAdvanceInterruptibly(phase,
+                                                        10,
+                                                        SECONDS);
+            if (expectNextPhase) check(AwaitPhase == (phase + 1));
+
+            pass();
+        } catch (Throwable t) {
+            unexpected(t);
+           // reset(atTheStartingGate);
+            throw new Error(t);
+        }
+    }
+
+    //----------------------------------------------------------------
+    // Convenience methods for creating threads that call arrive,
+    // awaitAdvance, arriveAndAwaitAdvance, awaitAdvanceInterruptibly
+    //----------------------------------------------------------------
+    private static abstract class Arriver extends Thread {
+        static AtomicInteger count = new AtomicInteger(1);
+
+        Arriver() {
+            this("Arriver");
+        }
+
+        Arriver(String name) {
+            this.setName(name + ":" + count.getAndIncrement());
+            this.setDaemon(true);
+        }
+
+        private volatile Throwable result;
+        private volatile int phase;
+        protected void result(Throwable result) { this.result = result; }
+        public Throwable result() { return this.result; }
+        protected void phase(int phase) { this.phase = phase; }
+        public int phase() { return this.phase; }
+    }
+
+    private static abstract class Awaiter extends Arriver {
+        Awaiter() { super("Awaiter"); }
+        Awaiter(String name) { super(name); }
+    }
+
+    private static Arriver arriver(final Phaser phaser) {
+        return new Arriver() { public void run() {
+            toTheStartingGate();
+
+            try { phase(phaser.arrive()); }
+            catch (Throwable result) { result(result); }}};
+    }
+
+    private static AtomicInteger cycleArriveAwaitAdvance = new AtomicInteger(1);
+
+    private static Awaiter awaiter(final Phaser phaser) {
+        return new Awaiter() { public void run() {
+            toTheStartingGate();
+
+            try {
+                if (cycleArriveAwaitAdvance.getAndIncrement() % 2 == 0)
+                    phase(phaser.awaitAdvance(phaser.arrive()));
+                else
+                    phase(phaser.arriveAndAwaitAdvance());
+            } catch (Throwable result) { result(result); }}};
+    }
+
+    private static Awaiter awaiter(final Phaser phaser,
+                                   final long timeout,
+                                   final TimeUnit unit) {
+        return new Awaiter("InterruptibleWaiter") { public void run() {
+            toTheStartingGate();
+
+            try {
+                if (timeout < 0)
+                    phase(phaser.awaitAdvanceInterruptibly(phaser.arrive()));
+                else
+                    phase(phaser.awaitAdvanceInterruptibly(phaser.arrive(),
+                                                     timeout,
+                                                     unit));
+            } catch (Throwable result) { result(result); }}};
+    }
+
+    // Returns an infinite lazy list of all possible arriver/awaiter combinations.
+    private static Iterator<Arriver> arriverIterator(final Phaser phaser) {
+        return new Iterator<Arriver>() {
+            int i = 0;
+            public boolean hasNext() { return true; }
+            public Arriver next() {
+                switch ((i++)&7) {
+                    case 0: case 4:
+                        return arriver(phaser);
+                    case 1: case 5:
+                        return awaiter(phaser);
+                    case 2: case 6: case 7:
+                        return awaiter(phaser, -1, SECONDS);
+                    default:
+                        return awaiter(phaser, 10, SECONDS); }}
+            public void remove() {throw new UnsupportedOperationException();}};
+    }
+
+    // Returns an infinite lazy list of all possible awaiter only combinations.
+    private static Iterator<Awaiter> awaiterIterator(final Phaser phaser) {
+        return new Iterator<Awaiter>() {
+            int i = 0;
+            public boolean hasNext() { return true; }
+            public Awaiter next() {
+                switch ((i++)&7) {
+                    case 1: case 4: case 7:
+                        return awaiter(phaser);
+                    case 2: case 5:
+                        return awaiter(phaser, -1, SECONDS);
+                    default:
+                        return awaiter(phaser, 10, SECONDS); }}
+            public void remove() {throw new UnsupportedOperationException();}};
+    }
+
+    private static void realMain(String[] args) throws Throwable {
+
+        Thread.currentThread().setName("mainThread");
+
+        //----------------------------------------------------------------
+        // Normal use
+        //----------------------------------------------------------------
+        try {
+            Phaser phaser = new Phaser(3);
+            equal(phaser.getRegisteredParties(), 3);
+            equal(phaser.getArrivedParties(), 0);
+            equal(phaser.getPhase(), 0);
+            check(phaser.getRoot().equals(phaser));
+            equal(phaser.getParent(), null);
+            check(!phaser.isTerminated());
+
+            Iterator<Arriver> arrivers = arriverIterator(phaser);
+            int phase = 0;
+            for (int i = 0; i < 10; i++) {
+                equal(phaser.getPhase(), phase++);
+                Arriver a1 = arrivers.next(); a1.start();
+                Arriver a2 = arrivers.next(); a2.start();
+                toTheStartingGate();
+                phaser.arriveAndAwaitAdvance();
+                a1.join();
+                a2.join();
+                checkResult(a1, null);
+                checkResult(a2, null);
+                check(!phaser.isTerminated());
+                equal(phaser.getRegisteredParties(), 3);
+                equal(phaser.getArrivedParties(), 0);
+            }
+        } catch (Throwable t) { unexpected(t); }
+
+        //----------------------------------------------------------------
+        // One thread interrupted
+        //----------------------------------------------------------------
+        try {
+            Phaser phaser = new Phaser(3);
+            Iterator<Arriver> arrivers = arriverIterator(phaser);
+            int phase = phaser.getPhase();
+            for (int i = 0; i < 4; i++) {
+                check(phaser.getPhase() == phase);
+                Awaiter a1 = awaiter(phaser, 10, SECONDS); a1.start();
+                Arriver a2 = arrivers.next(); a2.start();
+                toTheStartingGate();
+                a1.interrupt();
+                a1.join();
+                phaser.arriveAndAwaitAdvance();
+                a2.join();
+                checkResult(a1, InterruptedException.class);
+                checkResult(a2, null);
+                check(!phaser.isTerminated());
+                equal(phaser.getRegisteredParties(), 3);
+                equal(phaser.getArrivedParties(), 0);
+                phase++;
+            }
+        } catch (Throwable t) { unexpected(t); }
+
+        //----------------------------------------------------------------
+        // Phaser is terminated while threads are waiting
+        //----------------------------------------------------------------
+        try {
+            Phaser phaser = new Phaser(3);
+            Iterator<Awaiter> awaiters = awaiterIterator(phaser);
+            for (int i = 0; i < 4; i++) {
+                Arriver a1 = awaiters.next(); a1.start();
+                Arriver a2 = awaiters.next(); a2.start();
+                toTheStartingGate();
+                while (phaser.getArrivedParties() < 2) Thread.yield();
+                phaser.forceTermination();
+                a1.join();
+                a2.join();
+                check(a1.phase == -1);
+                check(a2.phase == -1);
+                int arrivedParties = phaser.getArrivedParties();
+                checkTerminated(phaser);
+                equal(phaser.getArrivedParties(), arrivedParties);
+            }
+        } catch (Throwable t) { unexpected(t); }
+
+        //----------------------------------------------------------------
+        // Adds new unarrived parties to this phaser
+        //----------------------------------------------------------------
+        try {
+            Phaser phaser = new Phaser(1);
+            Iterator<Arriver> arrivers = arriverIterator(phaser);
+            LinkedList<Arriver> arriverList = new LinkedList<Arriver>();
+            int phase = phaser.getPhase();
+            for (int i = 1; i < 5; i++) {
+                atTheStartingGate = new Phaser(1+(3*i));
+                check(phaser.getPhase() == phase);
+                // register 3 more
+                phaser.register(); phaser.register(); phaser.register();
+                for (int z=0; z<(3*i); z++) {
+                   arriverList.add(arrivers.next());
+                }
+                for (Arriver arriver : arriverList)
+                    arriver.start();
+
+                toTheStartingGate();
+                phaser.arriveAndAwaitAdvance();
+
+                for (Arriver arriver : arriverList) {
+                    arriver.join();
+                    checkResult(arriver, null);
+                }
+                equal(phaser.getRegisteredParties(), 1 + (3*i));
+                equal(phaser.getArrivedParties(), 0);
+                arriverList.clear();
+                phase++;
+            }
+            atTheStartingGate = new Phaser(3);
+        } catch (Throwable t) { unexpected(t); }
+
+        //----------------------------------------------------------------
+        // One thread timed out
+        //----------------------------------------------------------------
+        try {
+            Phaser phaser = new Phaser(3);
+            Iterator<Arriver> arrivers = arriverIterator(phaser);
+            for (long timeout : new long[] { 0L, 5L }) {
+                for (int i = 0; i < 2; i++) {
+                    Awaiter a1 = awaiter(phaser, timeout, SECONDS); a1.start();
+                    Arriver a2 = arrivers.next();                   a2.start();
+                    toTheStartingGate();
+                    a1.join();
+                    checkResult(a1, TimeoutException.class);
+                    phaser.arrive();
+                    a2.join();
+                    checkResult(a2, null);
+                    check(!phaser.isTerminated());
+                }
+            }
+        } catch (Throwable t) { unexpected(t); }
+
+        //----------------------------------------------------------------
+        // Barrier action completed normally
+        //----------------------------------------------------------------
+        try {
+            final AtomicInteger count = new AtomicInteger(0);
+            final Phaser[] kludge = new Phaser[1];
+            Phaser phaser = new Phaser(3) {
+                @Override
+                protected boolean onAdvance(int phase, int registeredParties) {
+                    int countPhase = count.getAndIncrement();
+                    equal(countPhase, phase);
+                    equal(kludge[0].getPhase(), phase);
+                    equal(kludge[0].getRegisteredParties(), registeredParties);
+                    if (phase >= 3)
+                        return true; // terminate
+
+                    return false;
+                }
+            };
+            kludge[0] = phaser;
+            equal(phaser.getRegisteredParties(), 3);
+            Iterator<Awaiter> awaiters = awaiterIterator(phaser);
+            for (int i = 0; i < 4; i++) {
+                Awaiter a1 = awaiters.next(); a1.start();
+                Awaiter a2 = awaiters.next(); a2.start();
+                toTheStartingGate();
+                while (phaser.getArrivedParties() < 2) Thread.yield();
+                phaser.arrive();
+                a1.join();
+                a2.join();
+                checkResult(a1, null);
+                checkResult(a2, null);
+                equal(count.get(), i+1);
+                if (i < 3) {
+                    check(!phaser.isTerminated());
+                    equal(phaser.getRegisteredParties(), 3);
+                    equal(phaser.getArrivedParties(), 0);
+                    equal(phaser.getUnarrivedParties(), 3);
+                    equal(phaser.getPhase(), count.get());
+                } else
+                    checkTerminated(phaser);
+            }
+        } catch (Throwable t) { unexpected(t); }
+
+    }
+
+    //--------------------- Infrastructure ---------------------------
+    static volatile int passed = 0, failed = 0;
+    static void pass() {passed++;}
+    static void fail() {failed++; Thread.dumpStack();}
+    static void fail(String msg) {System.out.println(msg); fail();}
+    static void unexpected(Throwable t) {failed++; t.printStackTrace();}
+    static void check(boolean cond) {if (cond) pass(); else fail();}
+    static void equal(Object x, Object y) {
+        if (x == null ? y == null : x.equals(y)) pass();
+        else fail(x + " not equal to " + y);}
+    public static void main(String[] args) throws Throwable {
+        try {realMain(args);} catch (Throwable t) {unexpected(t);}
+        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
+        if (failed > 0) throw new AssertionError("Some tests failed");}
+}

jdk/test/java/util/concurrent/ScheduledThreadPoolExecutor/DelayOverflow.java

@@ -20,6 +20,17 @@
  * 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 6725789

jdk/test/java/util/concurrent/forkjoin/Integrate.java

@@ -0,0 +1,265 @@
+/*
+ * 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 6865571
+ * @summary Numerical Integration using fork/join
+ * @run main Integrate reps=1 forkPolicy=dynamic
+ * @run main Integrate reps=1 forkPolicy=serial
+ * @run main Integrate reps=1 forkPolicy=fork
+ */
+
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.RecursiveAction;
+
+/**
+ * Sample program using Gaussian Quadrature for numerical integration.
+ * This version uses a simplified hardwired function.  Inspired by a
+ * <A href="http://www.cs.uga.edu/~dkl/filaments/dist.html">
+ * Filaments</A> demo program.
+ */
+public final class Integrate {
+
+    static final double errorTolerance = 1.0e-11;
+    /** for time conversion */
+    static final long NPS = (1000L * 1000 * 1000);
+
+    static final int SERIAL = -1;
+    static final int DYNAMIC = 0;
+    static final int FORK = 1;
+
+    // the function to integrate
+    static double computeFunction(double x)  {
+        return (x * x + 1.0) * x;
+    }
+
+    static final double start = 0.0;
+    static final double end = 1536.0;
+    /*
+     * The number of recursive calls for
+     * integrate from start to end.
+     * (Empirically determined)
+     */
+    static final int calls = 263479047;
+
+    static String keywordValue(String[] args, String keyword) {
+        for (String arg : args)
+            if (arg.startsWith(keyword))
+                return arg.substring(keyword.length() + 1);
+        return null;
+    }
+
+    static int intArg(String[] args, String keyword, int defaultValue) {
+        String val = keywordValue(args, keyword);
+        return (val == null) ? defaultValue : Integer.parseInt(val);
+    }
+
+    static int policyArg(String[] args, String keyword, int defaultPolicy) {
+        String val = keywordValue(args, keyword);
+        if (val == null) return defaultPolicy;
+        if (val.equals("dynamic")) return DYNAMIC;
+        if (val.equals("serial")) return SERIAL;
+        if (val.equals("fork")) return FORK;
+        throw new Error();
+    }
+
+    /**
+     * Usage: Integrate [procs=N] [reps=N] forkPolicy=serial|dynamic|fork
+     */
+    public static void main(String[] args) throws Exception {
+        final int procs = intArg(args, "procs",
+                                 Runtime.getRuntime().availableProcessors());
+        final int forkPolicy = policyArg(args, "forkPolicy", DYNAMIC);
+
+        ForkJoinPool g = new ForkJoinPool(procs);
+        System.out.println("Integrating from " + start + " to " + end +
+                           " forkPolicy = " + forkPolicy);
+        long lastTime = System.nanoTime();
+
+        for (int reps = intArg(args, "reps", 10); reps > 0; reps--) {
+            double a;
+            if (forkPolicy == SERIAL)
+                a = SQuad.computeArea(g, start, end);
+            else if (forkPolicy == FORK)
+                a = FQuad.computeArea(g, start, end);
+            else
+                a = DQuad.computeArea(g, start, end);
+            long now = System.nanoTime();
+            double s = (double) (now - lastTime) / NPS;
+            lastTime = now;
+            System.out.printf("Calls/sec: %12d", (long) (calls / s));
+            System.out.printf(" Time: %7.3f", s);
+            System.out.printf(" Area: %12.1f", a);
+            System.out.println();
+        }
+        System.out.println(g);
+        g.shutdown();
+    }
+
+
+    // Sequential version
+    static final class SQuad extends RecursiveAction {
+        static double computeArea(ForkJoinPool pool, double l, double r) {
+            SQuad q = new SQuad(l, r, 0);
+            pool.invoke(q);
+            return q.area;
+        }
+
+        final double left;       // lower bound
+        final double right;      // upper bound
+        double area;
+
+        SQuad(double l, double r, double a) {
+            this.left = l; this.right = r; this.area = a;
+        }
+
+        public final void compute() {
+            double l = left;
+            double r = right;
+            area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
+        }
+
+        static final double recEval(double l, double r, double fl,
+                                    double fr, double a) {
+            double h = (r - l) * 0.5;
+            double c = l + h;
+            double fc = (c * c + 1.0) * c;
+            double hh = h * 0.5;
+            double al = (fl + fc) * hh;
+            double ar = (fr + fc) * hh;
+            double alr = al + ar;
+            if (Math.abs(alr - a) <= errorTolerance)
+                return alr;
+            else
+                return recEval(c, r, fc, fr, ar) + recEval(l, c, fl, fc, al);
+        }
+
+    }
+
+    //....................................
+
+    // ForkJoin version
+    static final class FQuad extends RecursiveAction {
+        static double computeArea(ForkJoinPool pool, double l, double r) {
+            FQuad q = new FQuad(l, r, 0);
+            pool.invoke(q);
+            return q.area;
+        }
+
+        final double left;       // lower bound
+        final double right;      // upper bound
+        double area;
+
+        FQuad(double l, double r, double a) {
+            this.left = l; this.right = r; this.area = a;
+        }
+
+        public final void compute() {
+            double l = left;
+            double r = right;
+            area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
+        }
+
+        static final double recEval(double l, double r, double fl,
+                                    double fr, double a) {
+            double h = (r - l) * 0.5;
+            double c = l + h;
+            double fc = (c * c + 1.0) * c;
+            double hh = h * 0.5;
+            double al = (fl + fc) * hh;
+            double ar = (fr + fc) * hh;
+            double alr = al + ar;
+            if (Math.abs(alr - a) <= errorTolerance)
+                return alr;
+            FQuad q = new FQuad(l, c, al);
+            q.fork();
+            ar = recEval(c, r, fc, fr, ar);
+            if (!q.tryUnfork()) {
+                q.quietlyHelpJoin();
+                return ar + q.area;
+            }
+            return ar + recEval(l, c, fl, fc, al);
+        }
+
+    }
+
+    // ...........................
+
+    // Version using on-demand Fork
+    static final class DQuad extends RecursiveAction {
+        static double computeArea(ForkJoinPool pool, double l, double r) {
+            DQuad q = new DQuad(l, r, 0);
+            pool.invoke(q);
+            return q.area;
+        }
+
+        final double left;       // lower bound
+        final double right;      // upper bound
+        double area;
+
+        DQuad(double l, double r, double a) {
+            this.left = l; this.right = r; this.area = a;
+        }
+
+        public final void compute() {
+            double l = left;
+            double r = right;
+            area = recEval(l, r, (l * l + 1.0) * l, (r * r + 1.0) * r, area);
+        }
+
+        static final double recEval(double l, double r, double fl,
+                                    double fr, double a) {
+            double h = (r - l) * 0.5;
+            double c = l + h;
+            double fc = (c * c + 1.0) * c;
+            double hh = h * 0.5;
+            double al = (fl + fc) * hh;
+            double ar = (fr + fc) * hh;
+            double alr = al + ar;
+            if (Math.abs(alr - a) <= errorTolerance)
+                return alr;
+            DQuad q = null;
+            if (getSurplusQueuedTaskCount() <= 3)
+                (q = new DQuad(l, c, al)).fork();
+            ar = recEval(c, r, fc, fr, ar);
+            if (q != null && !q.tryUnfork()) {
+                q.quietlyHelpJoin();
+                return ar + q.area;
+            }
+            return ar + recEval(l, c, fl, fc, al);
+        }
+
+    }
+
+}

jdk/test/java/util/concurrent/forkjoin/NQueensCS.java

@@ -0,0 +1,174 @@
+/*
+ * 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 6865571
+ * @summary Solve NQueens using fork/join
+ * @run main NQueensCS maxBoardSize=11 reps=1
+ * @run main NQueensCS maxBoardSize=11 reps=1 procs=8
+ */
+
+import java.util.Arrays;
+import java.util.concurrent.ForkJoinPool;
+import java.util.concurrent.RecursiveAction;
+
+public class NQueensCS extends RecursiveAction {
+
+    static long lastStealCount;
+    static int boardSize;
+
+    static final int[] expectedSolutions = new int[] {
+        0, 1, 0, 0, 2, 10, 4, 40, 92, 352, 724, 2680, 14200,
+        73712, 365596, 2279184, 14772512, 95815104, 666090624
+    }; // see http://www.durangobill.com/N_Queens.html
+
+    static String keywordValue(String[] args, String keyword) {
+        for (String arg : args)
+            if (arg.startsWith(keyword))
+                return arg.substring(keyword.length() + 1);
+        return null;
+    }
+
+    static int intArg(String[] args, String keyword, int defaultValue) {
+        String val = keywordValue(args, keyword);
+        return (val == null) ? defaultValue : Integer.parseInt(val);
+    }
+
+    /** for time conversion */
+    static final long NPS = (1000L * 1000L * 1000L);
+
+    /**
+     * Usage: NQueensCS [minBoardSize=N] [maxBoardSize=N] [procs=N] [reps=N]
+     */
+    public static void main(String[] args) throws Exception {
+        // Board sizes too small: hard to measure well.
+        // Board sizes too large: take too long to run.
+        final int minBoardSize = intArg(args, "minBoardSize",  8);
+        final int maxBoardSize = intArg(args, "maxBoardSize", 15);
+
+        final int procs = intArg(args, "procs", 0);
+
+        for (int reps = intArg(args, "reps", 10); reps > 0; reps--) {
+            ForkJoinPool g = (procs == 0) ?
+                new ForkJoinPool() :
+                new ForkJoinPool(procs);
+            lastStealCount = g.getStealCount();
+            for (int i = minBoardSize; i <= maxBoardSize; i++)
+                test(g, i);
+            System.out.println(g);
+            g.shutdown();
+        }
+    }
+
+    static void test(ForkJoinPool g, int i) throws Exception {
+        boardSize = i;
+        int ps = g.getParallelism();
+        long start = System.nanoTime();
+        NQueensCS task = new NQueensCS(new int[0]);
+        g.invoke(task);
+        int solutions = task.solutions;
+        long time = System.nanoTime() - start;
+        double secs = (double) time / NPS;
+        if (solutions != expectedSolutions[i])
+            throw new Error();
+        System.out.printf("NQueensCS %3d", i);
+        System.out.printf(" Time: %7.3f", secs);
+        long sc = g.getStealCount();
+        long ns = sc - lastStealCount;
+        lastStealCount = sc;
+        System.out.printf(" Steals/t: %5d", ns/ps);
+        System.out.println();
+    }
+
+    // Boards are represented as arrays where each cell
+    // holds the column number of the queen in that row
+
+    final int[] sofar;
+    NQueensCS nextSubtask; // to link subtasks
+    int solutions;
+    NQueensCS(int[] a) {
+        this.sofar = a;
+    }
+
+    public final void compute() {
+        NQueensCS subtasks;
+        int bs = boardSize;
+        if (sofar.length >= bs)
+            solutions = 1;
+        else if ((subtasks = explore(sofar, bs)) != null)
+            solutions = processSubtasks(subtasks);
+    }
+
+    private static NQueensCS explore(int[] array, int bs) {
+        int row = array.length;
+        NQueensCS s = null; // subtask list
+        outer:
+        for (int q = 0; q < bs; ++q) {
+            for (int i = 0; i < row; i++) {
+                int p = array[i];
+                if (q == p || q == p - (row - i) || q == p + (row - i))
+                    continue outer; // attacked
+            }
+            NQueensCS first = s; // lag forks to ensure 1 kept
+            if (first != null)
+                first.fork();
+            int[] next = Arrays.copyOf(array, row+1);
+            next[row] = q;
+            NQueensCS subtask = new NQueensCS(next);
+            subtask.nextSubtask = first;
+            s = subtask;
+        }
+        return s;
+    }
+
+    private static int processSubtasks(NQueensCS s) {
+        // Always run first the task held instead of forked
+        s.compute();
+        int ns = s.solutions;
+        s = s.nextSubtask;
+        // Then the unstolen ones
+        while (s != null && s.tryUnfork()) {
+            s.compute();
+            ns += s.solutions;
+            s = s.nextSubtask;
+        }
+        // Then wait for the stolen ones
+        while (s != null) {
+            s.join();
+            ns += s.solutions;
+            s = s.nextSubtask;
+        }
+        return ns;
+    }
+}

jdk/test/java/util/concurrent/locks/ReentrantLock/CancelledLockLoops.java

@@ -115,7 +115,7 @@ public final class CancelledLockLoops {
             finally {
                 lock.unlock();
             }
-            if (completed != 2)
+            if (c != 2)
                 throw new Error("Completed != 2");
             int r = result;
             if (r == 0) // avoid overoptimization

jdk/test/java/util/concurrent/locks/ReentrantReadWriteLock/RWMap.java

@@ -30,6 +30,7 @@
  * Expert Group and released to the public domain, as explained at
  * http://creativecommons.org/licenses/publicdomain
  */
+
 import java.util.*;
 import java.util.concurrent.*;
 import java.util.concurrent.locks.*;