jdk8-mips64-public/hotspot: src/share/vm/utilities/workgroup.hpp@8b10f48633dc (annotated)

src/share/vm/utilities/workgroup.hpp@8b10f48633dc (annotated)

src/share/vm/utilities/workgroup.hpp

Mon, 20 Sep 2010 14:38:38 -0700

author: jmasa
date: Mon, 20 Sep 2010 14:38:38 -0700
changeset 2188: 8b10f48633dc
parent 1907: c18cbe5936b8
child 2314: f95d63e2154a
permissions: -rw-r--r--

6984287: Regularize how GC parallel workers are specified.
Summary: Associate number of GC workers with the workgang as opposed to the task.
Reviewed-by: johnc, ysr

 /*
  * Copyright (c) 2002, 2010, 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.
  *
  */
 // 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(int i) = 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;
   }
   virtual ~AbstractGangTask() { }
 };
 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 {
   // 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();
 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.
   int _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.
   int _started_workers;
   // The number of finished workers.
   int _finished_workers;
 public:
   // Accessors for fields
   Monitor* monitor() const {
     return _monitor;
   }
   int total_workers() const {
     return _total_workers;
   }
   virtual int 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;
   }
   int started_workers() const {
     return _started_workers;
   }
   int 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(int 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, int 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(int 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; }
 };
 class FlexibleWorkGang: public WorkGang {
  protected:
   int _active_workers;
  public:
   // Constructor and destructor.
   FlexibleWorkGang(const char* name, int workers,
                    bool are_GC_task_threads,
                    bool  are_ConcurrentGC_threads) :
     WorkGang(name, workers, are_GC_task_threads, are_ConcurrentGC_threads) {
     _active_workers = ParallelGCThreads;
   };
   // Accessors for fields
   virtual int active_workers() const { return _active_workers; }
   void set_active_workers(int v) { _active_workers = v; }
 };
 // 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;
   int     _n_workers;
   int     _n_completed;
   bool    _should_reset;
   Monitor* monitor()        { return &_monitor; }
   int      n_workers()      { return _n_workers; }
   int      n_completed()    { return _n_completed; }
   bool     should_reset()   { return _should_reset; }
   void     zero_completed() { _n_completed = 0; }
   void     inc_completed()  { _n_completed++; }
   void     set_should_reset(bool v) { _should_reset = v; }
 public:
   WorkGangBarrierSync();
   WorkGangBarrierSync(int 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(int 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.
   void enter();
 };
 // 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 {
   jint* _tasks;
   int _n_tasks;
   int _n_threads;
   jint _threads_completed;
 #ifdef ASSERT
   volatile jint _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(int 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.
   int n_threads() { return _n_threads; }
   void set_n_threads(int 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(int 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:
   jint _n_tasks;     // Total number of tasks available.
   jint _n_claimed;   // Number of tasks claimed.
   // _n_threads is used to determine when a sub task is done.
   // See comments on SubTasksDone::_n_threads
   jint _n_threads;   // Total number of parallel threads.
   jint _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
   jint 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.
   int n_threads() { return _n_threads; }
   void set_n_threads(int 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(int 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(int& 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 {
   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);
 };

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/utilities/workgroup.hpp@8b10f48633dc (annotated)

src/share/vm/utilities/workgroup.hpp