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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * 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.

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#ifndef SHARE_GC_SHARED_WEAKPROCESSOR_HPP

#define SHARE_GC_SHARED_WEAKPROCESSOR_HPP

#include "gc/shared/oopStorageParState.hpp"

#include "gc/shared/workgroup.hpp"

#include "memory/allocation.hpp"

class WeakProcessorPhaseTimes;

class WorkGang;

// Helper class to aid in root scanning and cleaning of weak oops in the VM.

//

// New containers of weak oops added to this class will automatically

// be cleaned by all GCs, including the young generation GCs.

class WeakProcessor : AllStatic {

public:

  // Visit all oop*s and apply the keep_alive closure if the referenced

  // object is considered alive by the is_alive closure, otherwise do some

  // container specific cleanup of element holding the oop.

  static void weak_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive);

  // Visit all oop*s and apply the given closure.

  static void oops_do(OopClosure* closure);

  // Parallel version.  Uses ergo_workers(), active workers, and

  // phase_time's max_threads to determine the number of threads to use.

  // IsAlive must be derived from BoolObjectClosure.

  // KeepAlive must be derived from OopClosure.

  template<typename IsAlive, typename KeepAlive>

  static void weak_oops_do(WorkGang* workers,

                           IsAlive* is_alive,

                           KeepAlive* keep_alive,

                           WeakProcessorPhaseTimes* phase_times);

  // Convenience parallel version.  Uses ergo_workers() and active workers

  // to determine the number of threads to run.  Implicitly logs phase times.

  // IsAlive must be derived from BoolObjectClosure.

  // KeepAlive must be derived from OopClosure.

  template<typename IsAlive, typename KeepAlive>

  static void weak_oops_do(WorkGang* workers,

                           IsAlive* is_alive,

                           KeepAlive* keep_alive,

                           uint indent_log);

  static uint ergo_workers(uint max_workers);

  class Task;

private:

  class GangTask;

};

class WeakProcessor::Task {

  typedef OopStorage::ParState<false, false> StorageState;

  WeakProcessorPhaseTimes* _phase_times;

  uint _nworkers;

  SubTasksDone _serial_phases_done;

  StorageState* _storage_states;

  void initialize();

public:

  Task(uint nworkers);          // No time tracking.

  Task(WeakProcessorPhaseTimes* phase_times, uint nworkers);

  ~Task();

  template<typename IsAlive, typename KeepAlive>

  void work(uint worker_id, IsAlive* is_alive, KeepAlive* keep_alive);

};

#endif // SHARE_GC_SHARED_WEAKPROCESSOR_HPP