/*

 * Copyright (c) 2005, 2018, 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.

 *

 */

#include "precompiled.hpp"

#include "classfile/systemDictionary.hpp"

#include "gc/parallel/gcTaskManager.hpp"

#include "gc/parallel/objectStartArray.hpp"

#include "gc/parallel/parMarkBitMap.inline.hpp"

#include "gc/parallel/parallelScavengeHeap.hpp"

#include "gc/parallel/psCompactionManager.inline.hpp"

#include "gc/parallel/psOldGen.hpp"

#include "gc/parallel/psParallelCompact.inline.hpp"

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

#include "logging/log.hpp"

#include "memory/iterator.inline.hpp"

#include "oops/access.inline.hpp"

#include "oops/compressedOops.inline.hpp"

#include "oops/instanceKlass.inline.hpp"

#include "oops/instanceMirrorKlass.inline.hpp"

#include "oops/objArrayKlass.inline.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/atomic.hpp"

PSOldGen*            ParCompactionManager::_old_gen = NULL;

ParCompactionManager**  ParCompactionManager::_manager_array = NULL;

OopTaskQueueSet*     ParCompactionManager::_stack_array = NULL;

ParCompactionManager::ObjArrayTaskQueueSet*

  ParCompactionManager::_objarray_queues = NULL;

ObjectStartArray*    ParCompactionManager::_start_array = NULL;

ParMarkBitMap*       ParCompactionManager::_mark_bitmap = NULL;

RegionTaskQueueSet*  ParCompactionManager::_region_array = NULL;

ParCompactionManager::ParCompactionManager() :

    _action(CopyAndUpdate) {

  ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();

  _old_gen = heap->old_gen();

  _start_array = old_gen()->start_array();

  marking_stack()->initialize();

  _objarray_stack.initialize();

  _region_stack.initialize();

  reset_bitmap_query_cache();

}

void ParCompactionManager::initialize(ParMarkBitMap* mbm) {

  assert(PSParallelCompact::gc_task_manager() != NULL,

    "Needed for initialization");

  _mark_bitmap = mbm;

  uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers();

  assert(_manager_array == NULL, "Attempt to initialize twice");

  _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, mtGC);

  guarantee(_manager_array != NULL, "Could not allocate manager_array");

  _stack_array = new OopTaskQueueSet(parallel_gc_threads);

  guarantee(_stack_array != NULL, "Could not allocate stack_array");

  _objarray_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);

  guarantee(_objarray_queues != NULL, "Could not allocate objarray_queues");

  _region_array = new RegionTaskQueueSet(parallel_gc_threads);

  guarantee(_region_array != NULL, "Could not allocate region_array");

  // Create and register the ParCompactionManager(s) for the worker threads.

  for(uint i=0; i<parallel_gc_threads; i++) {

    _manager_array[i] = new ParCompactionManager();

    guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager");

    stack_array()->register_queue(i, _manager_array[i]->marking_stack());

    _objarray_queues->register_queue(i, &_manager_array[i]->_objarray_stack);

    region_array()->register_queue(i, _manager_array[i]->region_stack());

  }

  // The VMThread gets its own ParCompactionManager, which is not available

  // for work stealing.

  _manager_array[parallel_gc_threads] = new ParCompactionManager();

  guarantee(_manager_array[parallel_gc_threads] != NULL,

    "Could not create ParCompactionManager");

  assert(PSParallelCompact::gc_task_manager()->workers() != 0,

    "Not initialized?");

}

void ParCompactionManager::reset_all_bitmap_query_caches() {

  uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers();

  for (uint i=0; i<=parallel_gc_threads; i++) {

    _manager_array[i]->reset_bitmap_query_cache();

  }

}

bool ParCompactionManager::should_update() {

  assert(action() != NotValid, "Action is not set");

  return (action() == ParCompactionManager::Update) ||

         (action() == ParCompactionManager::CopyAndUpdate) ||

         (action() == ParCompactionManager::UpdateAndCopy);

}

bool ParCompactionManager::should_copy() {

  assert(action() != NotValid, "Action is not set");

  return (action() == ParCompactionManager::Copy) ||

         (action() == ParCompactionManager::CopyAndUpdate) ||

         (action() == ParCompactionManager::UpdateAndCopy);

}

ParCompactionManager*

ParCompactionManager::gc_thread_compaction_manager(uint index) {

  assert(index < ParallelGCThreads, "index out of range");

  assert(_manager_array != NULL, "Sanity");

  return _manager_array[index];

}

void ParCompactionManager::follow_marking_stacks() {

  do {

    // Drain the overflow stack first, to allow stealing from the marking stack.

    oop obj;

    while (marking_stack()->pop_overflow(obj)) {

      follow_contents(obj);

    }

    while (marking_stack()->pop_local(obj)) {

      follow_contents(obj);

    }

    // Process ObjArrays one at a time to avoid marking stack bloat.

    ObjArrayTask task;

    if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) {

      follow_array((objArrayOop)task.obj(), task.index());

    }

  } while (!marking_stacks_empty());

  assert(marking_stacks_empty(), "Sanity");

}

void ParCompactionManager::drain_region_stacks() {

  do {

    // Drain overflow stack first so other threads can steal.

    size_t region_index;

    while (region_stack()->pop_overflow(region_index)) {

      PSParallelCompact::fill_and_update_region(this, region_index);

    }

    while (region_stack()->pop_local(region_index)) {

      PSParallelCompact::fill_and_update_region(this, region_index);

    }

  } while (!region_stack()->is_empty());

}