/*

 * Copyright (c) 2018, 2019, 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

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 */

#ifndef SHARE_GC_SHARED_WEAKPROCESSOR_INLINE_HPP

#define SHARE_GC_SHARED_WEAKPROCESSOR_INLINE_HPP

#include "classfile/stringTable.hpp"

#include "gc/shared/oopStorage.inline.hpp"

#include "gc/shared/oopStorageParState.inline.hpp"

#include "gc/shared/oopStorageSet.hpp"

#include "gc/shared/weakProcessor.hpp"

#include "gc/shared/weakProcessorPhases.hpp"

#include "gc/shared/weakProcessorPhaseTimes.hpp"

#include "gc/shared/workgroup.hpp"

#include "prims/resolvedMethodTable.hpp"

#include "utilities/debug.hpp"

class BoolObjectClosure;

class OopClosure;

template<typename IsAlive>

class CountingIsAliveClosure : public BoolObjectClosure {

  IsAlive* _inner;

  size_t _num_dead;

  size_t _num_total;

public:

  CountingIsAliveClosure(IsAlive* cl) : _inner(cl), _num_dead(0), _num_total(0) { }

  virtual bool do_object_b(oop obj) {

    bool result = _inner->do_object_b(obj);

    _num_dead += !result;

    _num_total++;

    return result;

  }

  size_t num_dead() const { return _num_dead; }

  size_t num_total() const { return _num_total; }

};

template <typename IsAlive, typename KeepAlive>

class CountingSkippedIsAliveClosure : public Closure {

  CountingIsAliveClosure<IsAlive> _counting_is_alive;

  KeepAlive* _keep_alive;

  size_t _num_skipped;

public:

  CountingSkippedIsAliveClosure(IsAlive* is_alive, KeepAlive* keep_alive) :

    _counting_is_alive(is_alive), _keep_alive(keep_alive), _num_skipped(0) { }

  void do_oop(oop* p) {

    oop obj = *p;

    if (obj == NULL) {

      _num_skipped++;

    } else if (_counting_is_alive.do_object_b(obj)) {

      _keep_alive->do_oop(p);

    } else {

      *p = NULL;

    }

  }

  size_t num_dead() const { return _counting_is_alive.num_dead(); }

  size_t num_skipped() const { return _num_skipped; }

  size_t num_total() const { return _counting_is_alive.num_total() + num_skipped(); }

};

template<typename IsAlive, typename KeepAlive>

void WeakProcessor::Task::work(uint worker_id,

                               IsAlive* is_alive,

                               KeepAlive* keep_alive) {

  assert(worker_id < _nworkers,

         "worker_id (%u) exceeds task's configured workers (%u)",

         worker_id, _nworkers);

  typedef WeakProcessorPhases::Iterator Iterator;

  for (Iterator it = WeakProcessorPhases::serial_iterator(); !it.is_end(); ++it) {

    WeakProcessorPhase phase = *it;

    CountingIsAliveClosure<IsAlive> cl(is_alive);

    uint serial_index = WeakProcessorPhases::serial_index(phase);

    if (_serial_phases_done.try_claim_task(serial_index)) {

      WeakProcessorPhaseTimeTracker pt(_phase_times, phase);

      WeakProcessorPhases::processor(phase)(&cl, keep_alive);

      if (_phase_times != NULL) {

        _phase_times->record_phase_items(phase, cl.num_dead(), cl.num_total());

      }

    }

  }

  for (Iterator it = WeakProcessorPhases::oopstorage_iterator(); !it.is_end(); ++it) {

    WeakProcessorPhase phase = *it;

    CountingSkippedIsAliveClosure<IsAlive, KeepAlive> cl(is_alive, keep_alive);

    WeakProcessorPhaseTimeTracker pt(_phase_times, phase, worker_id);

    uint oopstorage_index = WeakProcessorPhases::oopstorage_index(phase);

    StorageState& cur_state = _storage_states[oopstorage_index];

    cur_state.oops_do(&cl);

    if (_phase_times != NULL) {

      _phase_times->record_worker_items(worker_id, phase, cl.num_dead(), cl.num_total());

    }

    const OopStorage* cur_storage = cur_state.storage();

    if (cur_storage == OopStorageSet::string_table_weak()) {

      StringTable::inc_dead_counter(cl.num_dead() + cl.num_skipped());

    } else if (cur_storage == OopStorageSet::resolved_method_table_weak()) {

      ResolvedMethodTable::inc_dead_counter(cl.num_dead() + cl.num_skipped());

    }

  }

  _serial_phases_done.all_tasks_completed(_nworkers);

}

class WeakProcessor::GangTask : public AbstractGangTask {

  Task _task;

  BoolObjectClosure* _is_alive;

  OopClosure* _keep_alive;

  void (*_erased_do_work)(GangTask* task, uint worker_id);

  template<typename IsAlive, typename KeepAlive>

  static void erased_do_work(GangTask* task, uint worker_id) {

    task->_task.work(worker_id,

                     static_cast<IsAlive*>(task->_is_alive),

                     static_cast<KeepAlive*>(task->_keep_alive));

  }

public:

  template<typename IsAlive, typename KeepAlive>

  GangTask(const char* name,

           IsAlive* is_alive,

           KeepAlive* keep_alive,

           WeakProcessorPhaseTimes* phase_times,

           uint nworkers) :

    AbstractGangTask(name),

    _task(phase_times, nworkers),

    _is_alive(is_alive),

    _keep_alive(keep_alive),

    _erased_do_work(&erased_do_work<IsAlive, KeepAlive>)

  {}

  virtual void work(uint worker_id);

};

template<typename IsAlive, typename KeepAlive>

void WeakProcessor::weak_oops_do(WorkGang* workers,

                                 IsAlive* is_alive,

                                 KeepAlive* keep_alive,

                                 WeakProcessorPhaseTimes* phase_times) {

  WeakProcessorTimeTracker tt(phase_times);

  uint nworkers = ergo_workers(MIN2(workers->active_workers(),

                                    phase_times->max_threads()));

  GangTask task("Weak Processor", is_alive, keep_alive, phase_times, nworkers);

  workers->run_task(&task, nworkers);

}

template<typename IsAlive, typename KeepAlive>

void WeakProcessor::weak_oops_do(WorkGang* workers,

                                 IsAlive* is_alive,

                                 KeepAlive* keep_alive,

                                 uint indent_log) {

  uint nworkers = ergo_workers(workers->active_workers());

  WeakProcessorPhaseTimes pt(nworkers);

  weak_oops_do(workers, is_alive, keep_alive, &pt);

  pt.log_print_phases(indent_log);

}

#endif // SHARE_GC_SHARED_WEAKPROCESSOR_INLINE_HPP