diff -r 000000000000 -r f90c822e73f8 src/share/vm/utilities/workgroup.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/utilities/workgroup.hpp	Wed Apr 27 01:25:04 2016 +0800
@@ -0,0 +1,543 @@
+/*
+ * Copyright (c) 2002, 2013, Oracle and/or its affiliates. All rights reserved.
+ * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_UTILITIES_WORKGROUP_HPP
+#define SHARE_VM_UTILITIES_WORKGROUP_HPP
+
+#include "runtime/thread.inline.hpp"
+#include "utilities/taskqueue.hpp"
+
+// Task class hierarchy:
+//   AbstractGangTask
+//     AbstractGangTaskWOopQueues
+//
+// Gang/Group class hierarchy:
+//   AbstractWorkGang
+//     WorkGang
+//       FlexibleWorkGang
+//         YieldingFlexibleWorkGang (defined in another file)
+//
+// Worker class hierarchy:
+//   GangWorker (subclass of WorkerThread)
+//     YieldingFlexibleGangWorker   (defined in another file)
+
+// Forward declarations of classes defined here
+
+class WorkGang;
+class GangWorker;
+class YieldingFlexibleGangWorker;
+class YieldingFlexibleGangTask;
+class WorkData;
+class AbstractWorkGang;
+
+// An abstract task to be worked on by a gang.
+// You subclass this to supply your own work() method
+class AbstractGangTask VALUE_OBJ_CLASS_SPEC {
+public:
+  // The abstract work method.
+  // The argument tells you which member of the gang you are.
+  virtual void work(uint worker_id) = 0;
+
+  // This method configures the task for proper termination.
+  // Some tasks do not have any requirements on termination
+  // and may inherit this method that does nothing.  Some
+  // tasks do some coordination on termination and override
+  // this method to implement that coordination.
+  virtual void set_for_termination(int active_workers) {};
+
+  // Debugging accessor for the name.
+  const char* name() const PRODUCT_RETURN_(return NULL;);
+  int counter() { return _counter; }
+  void set_counter(int value) { _counter = value; }
+  int *address_of_counter() { return &_counter; }
+
+  // RTTI
+  NOT_PRODUCT(virtual bool is_YieldingFlexibleGang_task() const {
+    return false;
+  })
+
+private:
+  NOT_PRODUCT(const char* _name;)
+  // ??? Should a task have a priority associated with it?
+  // ??? Or can the run method adjust priority as needed?
+  int _counter;
+
+protected:
+  // Constructor and desctructor: only construct subclasses.
+  AbstractGangTask(const char* name)
+  {
+    NOT_PRODUCT(_name = name);
+    _counter = 0;
+  }
+  ~AbstractGangTask() { }
+
+public:
+};
+
+class AbstractGangTaskWOopQueues : public AbstractGangTask {
+  OopTaskQueueSet*       _queues;
+  ParallelTaskTerminator _terminator;
+ public:
+  AbstractGangTaskWOopQueues(const char* name, OopTaskQueueSet* queues) :
+    AbstractGangTask(name), _queues(queues), _terminator(0, _queues) {}
+  ParallelTaskTerminator* terminator() { return &_terminator; }
+  virtual void set_for_termination(int active_workers) {
+    terminator()->reset_for_reuse(active_workers);
+  }
+  OopTaskQueueSet* queues() { return _queues; }
+};
+
+
+// Class AbstractWorkGang:
+// An abstract class representing a gang of workers.
+// You subclass this to supply an implementation of run_task().
+class AbstractWorkGang: public CHeapObj<mtInternal> {
+  // Here's the public interface to this class.
+public:
+  // Constructor and destructor.
+  AbstractWorkGang(const char* name, bool are_GC_task_threads,
+                   bool are_ConcurrentGC_threads);
+  ~AbstractWorkGang();
+  // Run a task, returns when the task is done (or terminated).
+  virtual void run_task(AbstractGangTask* task) = 0;
+  // Stop and terminate all workers.
+  virtual void stop();
+  // Return true if more workers should be applied to the task.
+  virtual bool needs_more_workers() const { return true; }
+public:
+  // Debugging.
+  const char* name() const;
+protected:
+  // Initialize only instance data.
+  const bool _are_GC_task_threads;
+  const bool _are_ConcurrentGC_threads;
+  // Printing support.
+  const char* _name;
+  // The monitor which protects these data,
+  // and notifies of changes in it.
+  Monitor*  _monitor;
+  // The count of the number of workers in the gang.
+  uint _total_workers;
+  // Whether the workers should terminate.
+  bool _terminate;
+  // The array of worker threads for this gang.
+  // This is only needed for cleaning up.
+  GangWorker** _gang_workers;
+  // The task for this gang.
+  AbstractGangTask* _task;
+  // A sequence number for the current task.
+  int _sequence_number;
+  // The number of started workers.
+  uint _started_workers;
+  // The number of finished workers.
+  uint _finished_workers;
+public:
+  // Accessors for fields
+  Monitor* monitor() const {
+    return _monitor;
+  }
+  uint total_workers() const {
+    return _total_workers;
+  }
+  virtual uint active_workers() const {
+    return _total_workers;
+  }
+  bool terminate() const {
+    return _terminate;
+  }
+  GangWorker** gang_workers() const {
+    return _gang_workers;
+  }
+  AbstractGangTask* task() const {
+    return _task;
+  }
+  int sequence_number() const {
+    return _sequence_number;
+  }
+  uint started_workers() const {
+    return _started_workers;
+  }
+  uint finished_workers() const {
+    return _finished_workers;
+  }
+  bool are_GC_task_threads() const {
+    return _are_GC_task_threads;
+  }
+  bool are_ConcurrentGC_threads() const {
+    return _are_ConcurrentGC_threads;
+  }
+  // Predicates.
+  bool is_idle() const {
+    return (task() == NULL);
+  }
+  // Return the Ith gang worker.
+  GangWorker* gang_worker(uint i) const;
+
+  void threads_do(ThreadClosure* tc) const;
+
+  // Printing
+  void print_worker_threads_on(outputStream *st) const;
+  void print_worker_threads() const {
+    print_worker_threads_on(tty);
+  }
+
+protected:
+  friend class GangWorker;
+  friend class YieldingFlexibleGangWorker;
+  // Note activation and deactivation of workers.
+  // These methods should only be called with the mutex held.
+  void internal_worker_poll(WorkData* data) const;
+  void internal_note_start();
+  void internal_note_finish();
+};
+
+class WorkData: public StackObj {
+  // This would be a struct, but I want accessor methods.
+private:
+  bool              _terminate;
+  AbstractGangTask* _task;
+  int               _sequence_number;
+public:
+  // Constructor and destructor
+  WorkData() {
+    _terminate       = false;
+    _task            = NULL;
+    _sequence_number = 0;
+  }
+  ~WorkData() {
+  }
+  // Accessors and modifiers
+  bool terminate()                       const { return _terminate;  }
+  void set_terminate(bool value)               { _terminate = value; }
+  AbstractGangTask* task()               const { return _task; }
+  void set_task(AbstractGangTask* value)       { _task = value; }
+  int sequence_number()                  const { return _sequence_number; }
+  void set_sequence_number(int value)          { _sequence_number = value; }
+
+  YieldingFlexibleGangTask* yf_task()    const {
+    return (YieldingFlexibleGangTask*)_task;
+  }
+};
+
+// Class WorkGang:
+class WorkGang: public AbstractWorkGang {
+public:
+  // Constructor
+  WorkGang(const char* name, uint workers,
+           bool are_GC_task_threads, bool are_ConcurrentGC_threads);
+  // Run a task, returns when the task is done (or terminated).
+  virtual void run_task(AbstractGangTask* task);
+  void run_task(AbstractGangTask* task, uint no_of_parallel_workers);
+  // Allocate a worker and return a pointer to it.
+  virtual GangWorker* allocate_worker(uint which);
+  // Initialize workers in the gang.  Return true if initialization
+  // succeeded. The type of the worker can be overridden in a derived
+  // class with the appropriate implementation of allocate_worker().
+  bool initialize_workers();
+};
+
+// Class GangWorker:
+//   Several instances of this class run in parallel as workers for a gang.
+class GangWorker: public WorkerThread {
+public:
+  // Constructors and destructor.
+  GangWorker(AbstractWorkGang* gang, uint id);
+
+  // The only real method: run a task for the gang.
+  virtual void run();
+  // Predicate for Thread
+  virtual bool is_GC_task_thread() const;
+  virtual bool is_ConcurrentGC_thread() const;
+  // Printing
+  void print_on(outputStream* st) const;
+  virtual void print() const { print_on(tty); }
+protected:
+  AbstractWorkGang* _gang;
+
+  virtual void initialize();
+  virtual void loop();
+
+public:
+  AbstractWorkGang* gang() const { return _gang; }
+};
+
+// Dynamic number of worker threads
+//
+// This type of work gang is used to run different numbers of
+// worker threads at different times.  The
+// number of workers run for a task is "_active_workers"
+// instead of "_total_workers" in a WorkGang.  The method
+// "needs_more_workers()" returns true until "_active_workers"
+// have been started and returns false afterwards.  The
+// implementation of "needs_more_workers()" in WorkGang always
+// returns true so that all workers are started.  The method
+// "loop()" in GangWorker was modified to ask "needs_more_workers()"
+// in its loop to decide if it should start working on a task.
+// A worker in "loop()" waits for notification on the WorkGang
+// monitor and execution of each worker as it checks for work
+// is serialized via the same monitor.  The "needs_more_workers()"
+// call is serialized and additionally the calculation for the
+// "part" (effectively the worker id for executing the task) is
+// serialized to give each worker a unique "part".  Workers that
+// are not needed for this tasks (i.e., "_active_workers" have
+// been started before it, continue to wait for work.
+
+class FlexibleWorkGang: public WorkGang {
+  // The currently active workers in this gang.
+  // This is a number that is dynamically adjusted
+  // and checked in the run_task() method at each invocation.
+  // As described above _active_workers determines the number
+  // of threads started on a task.  It must also be used to
+  // determine completion.
+
+ protected:
+  uint _active_workers;
+ public:
+  // Constructor and destructor.
+  // Initialize active_workers to a minimum value.  Setting it to
+  // the parameter "workers" will initialize it to a maximum
+  // value which is not desirable.
+  FlexibleWorkGang(const char* name, uint workers,
+                   bool are_GC_task_threads,
+                   bool  are_ConcurrentGC_threads) :
+    WorkGang(name, workers, are_GC_task_threads, are_ConcurrentGC_threads),
+    _active_workers(UseDynamicNumberOfGCThreads ? 1U : ParallelGCThreads) {}
+  // Accessors for fields
+  virtual uint active_workers() const { return _active_workers; }
+  void set_active_workers(uint v) {
+    assert(v <= _total_workers,
+           "Trying to set more workers active than there are");
+    _active_workers = MIN2(v, _total_workers);
+    assert(v != 0, "Trying to set active workers to 0");
+    _active_workers = MAX2(1U, _active_workers);
+    assert(UseDynamicNumberOfGCThreads || _active_workers == _total_workers,
+           "Unless dynamic should use total workers");
+  }
+  virtual void run_task(AbstractGangTask* task);
+  virtual bool needs_more_workers() const {
+    return _started_workers < _active_workers;
+  }
+};
+
+// Work gangs in garbage collectors: 2009-06-10
+//
+// SharedHeap - work gang for stop-the-world parallel collection.
+//   Used by
+//     ParNewGeneration
+//     CMSParRemarkTask
+//     CMSRefProcTaskExecutor
+//     G1CollectedHeap
+//     G1ParFinalCountTask
+// ConcurrentMark
+// CMSCollector
+
+// A class that acts as a synchronisation barrier. Workers enter
+// the barrier and must wait until all other workers have entered
+// before any of them may leave.
+
+class WorkGangBarrierSync : public StackObj {
+protected:
+  Monitor _monitor;
+  uint    _n_workers;
+  uint    _n_completed;
+  bool    _should_reset;
+  bool    _aborted;
+
+  Monitor* monitor()        { return &_monitor; }
+  uint     n_workers()      { return _n_workers; }
+  uint     n_completed()    { return _n_completed; }
+  bool     should_reset()   { return _should_reset; }
+  bool     aborted()        { return _aborted; }
+
+  void     zero_completed() { _n_completed = 0; }
+  void     inc_completed()  { _n_completed++; }
+  void     set_aborted()    { _aborted = true; }
+  void     set_should_reset(bool v) { _should_reset = v; }
+
+public:
+  WorkGangBarrierSync();
+  WorkGangBarrierSync(uint n_workers, const char* name);
+
+  // Set the number of workers that will use the barrier.
+  // Must be called before any of the workers start running.
+  void set_n_workers(uint n_workers);
+
+  // Enter the barrier. A worker that enters the barrier will
+  // not be allowed to leave until all other threads have
+  // also entered the barrier or the barrier is aborted.
+  // Returns false if the barrier was aborted.
+  bool enter();
+
+  // Aborts the barrier and wakes up any threads waiting for
+  // the barrier to complete. The barrier will remain in the
+  // aborted state until the next call to set_n_workers().
+  void abort();
+};
+
+// A class to manage claiming of subtasks within a group of tasks.  The
+// subtasks will be identified by integer indices, usually elements of an
+// enumeration type.
+
+class SubTasksDone: public CHeapObj<mtInternal> {
+  uint* _tasks;
+  uint _n_tasks;
+  // _n_threads is used to determine when a sub task is done.
+  // It does not control how many threads will execute the subtask
+  // but must be initialized to the number that do execute the task
+  // in order to correctly decide when the subtask is done (all the
+  // threads working on the task have finished).
+  uint _n_threads;
+  uint _threads_completed;
+#ifdef ASSERT
+  volatile uint _claimed;
+#endif
+
+  // Set all tasks to unclaimed.
+  void clear();
+
+public:
+  // Initializes "this" to a state in which there are "n" tasks to be
+  // processed, none of the which are originally claimed.  The number of
+  // threads doing the tasks is initialized 1.
+  SubTasksDone(uint n);
+
+  // True iff the object is in a valid state.
+  bool valid();
+
+  // Get/set the number of parallel threads doing the tasks to "t".  Can only
+  // be called before tasks start or after they are complete.
+  uint n_threads() { return _n_threads; }
+  void set_n_threads(uint t);
+
+  // Returns "false" if the task "t" is unclaimed, and ensures that task is
+  // claimed.  The task "t" is required to be within the range of "this".
+  bool is_task_claimed(uint t);
+
+  // The calling thread asserts that it has attempted to claim all the
+  // tasks that it will try to claim.  Every thread in the parallel task
+  // must execute this.  (When the last thread does so, the task array is
+  // cleared.)
+  void all_tasks_completed();
+
+  // Destructor.
+  ~SubTasksDone();
+};
+
+// As above, but for sequential tasks, i.e. instead of claiming
+// sub-tasks from a set (possibly an enumeration), claim sub-tasks
+// in sequential order. This is ideal for claiming dynamically
+// partitioned tasks (like striding in the parallel remembered
+// set scanning). Note that unlike the above class this is
+// a stack object - is there any reason for it not to be?
+
+class SequentialSubTasksDone : public StackObj {
+protected:
+  uint _n_tasks;     // Total number of tasks available.
+  uint _n_claimed;   // Number of tasks claimed.
+  // _n_threads is used to determine when a sub task is done.
+  // See comments on SubTasksDone::_n_threads
+  uint _n_threads;   // Total number of parallel threads.
+  uint _n_completed; // Number of completed threads.
+
+  void clear();
+
+public:
+  SequentialSubTasksDone() {
+    clear();
+  }
+  ~SequentialSubTasksDone() {}
+
+  // True iff the object is in a valid state.
+  bool valid();
+
+  // number of tasks
+  uint n_tasks() const { return _n_tasks; }
+
+  // Get/set the number of parallel threads doing the tasks to t.
+  // Should be called before the task starts but it is safe
+  // to call this once a task is running provided that all
+  // threads agree on the number of threads.
+  uint n_threads() { return _n_threads; }
+  void set_n_threads(uint t) { _n_threads = t; }
+
+  // Set the number of tasks to be claimed to t. As above,
+  // should be called before the tasks start but it is safe
+  // to call this once a task is running provided all threads
+  // agree on the number of tasks.
+  void set_n_tasks(uint t) { _n_tasks = t; }
+
+  // Returns false if the next task in the sequence is unclaimed,
+  // and ensures that it is claimed. Will set t to be the index
+  // of the claimed task in the sequence. Will return true if
+  // the task cannot be claimed and there are none left to claim.
+  bool is_task_claimed(uint& t);
+
+  // The calling thread asserts that it has attempted to claim
+  // all the tasks it possibly can in the sequence. Every thread
+  // claiming tasks must promise call this. Returns true if this
+  // is the last thread to complete so that the thread can perform
+  // cleanup if necessary.
+  bool all_tasks_completed();
+};
+
+// Represents a set of free small integer ids.
+class FreeIdSet : public CHeapObj<mtInternal> {
+  enum {
+    end_of_list = -1,
+    claimed = -2
+  };
+
+  int _sz;
+  Monitor* _mon;
+
+  int* _ids;
+  int _hd;
+  int _waiters;
+  int _claimed;
+
+  static bool _safepoint;
+  typedef FreeIdSet* FreeIdSetPtr;
+  static const int NSets = 10;
+  static FreeIdSetPtr _sets[NSets];
+  static bool _stat_init;
+  int _index;
+
+public:
+  FreeIdSet(int sz, Monitor* mon);
+  ~FreeIdSet();
+
+  static void set_safepoint(bool b);
+
+  // Attempt to claim the given id permanently.  Returns "true" iff
+  // successful.
+  bool claim_perm_id(int i);
+
+  // Returns an unclaimed parallel id (waiting for one to be released if
+  // necessary).  Returns "-1" if a GC wakes up a wait for an id.
+  int claim_par_id();
+
+  void release_par_id(int id);
+};
+
+#endif // SHARE_VM_UTILITIES_WORKGROUP_HPP