/*

 * Copyright (c) 2017, 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 "gc/g1/g1CollectedHeap.hpp"

#include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"

#include "gc/g1/g1FullCollector.hpp"

#include "gc/g1/g1FullGCCompactionPoint.hpp"

#include "gc/g1/g1FullGCCompactTask.hpp"

#include "gc/g1/heapRegion.inline.hpp"

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

#include "logging/log.hpp"

#include "oops/oop.inline.hpp"

#include "utilities/ticks.hpp"

class G1ResetHumongousClosure : public HeapRegionClosure {

  G1CMBitMap* _bitmap;

public:

  G1ResetHumongousClosure(G1CMBitMap* bitmap) :

      _bitmap(bitmap) { }

  bool do_heap_region(HeapRegion* current) {

    if (current->is_humongous()) {

      if (current->is_starts_humongous()) {

        oop obj = oop(current->bottom());

        if (_bitmap->is_marked(obj)) {

          // Clear bitmap and fix mark word.

          _bitmap->clear(obj);

          obj->init_mark_raw();

        } else {

          assert(current->is_empty(), "Should have been cleared in phase 2.");

        }

      }

      current->reset_during_compaction();

    }

    return false;

  }

};

size_t G1FullGCCompactTask::G1CompactRegionClosure::apply(oop obj) {

  size_t size = obj->size();

  HeapWord* destination = (HeapWord*)obj->forwardee();

  if (destination == NULL) {

    // Object not moving

    return size;

  }

  // copy object and reinit its mark

  HeapWord* obj_addr = (HeapWord*) obj;

  assert(obj_addr != destination, "everything in this pass should be moving");

  Copy::aligned_conjoint_words(obj_addr, destination, size);

  oop(destination)->init_mark_raw();

  assert(oop(destination)->klass() != NULL, "should have a class");

  return size;

}

void G1FullGCCompactTask::compact_region(HeapRegion* hr) {

  assert(!hr->is_humongous(), "Should be no humongous regions in compaction queue");

  G1CompactRegionClosure compact(collector()->mark_bitmap());

  hr->apply_to_marked_objects(collector()->mark_bitmap(), &compact);

  // Once all objects have been moved the liveness information

  // needs be cleared.

  collector()->mark_bitmap()->clear_region(hr);

  hr->complete_compaction();

}

void G1FullGCCompactTask::work(uint worker_id) {

  Ticks start = Ticks::now();

  GrowableArray<HeapRegion*>* compaction_queue = collector()->compaction_point(worker_id)->regions();

  for (GrowableArrayIterator<HeapRegion*> it = compaction_queue->begin();

       it != compaction_queue->end();

       ++it) {

    compact_region(*it);

  }

  G1ResetHumongousClosure hc(collector()->mark_bitmap());

  G1CollectedHeap::heap()->heap_region_par_iterate_from_worker_offset(&hc, &_claimer, worker_id);

  log_task("Compaction task", worker_id, start);

}

void G1FullGCCompactTask::serial_compaction() {

  GCTraceTime(Debug, gc, phases) tm("Phase 4: Serial Compaction", collector()->scope()->timer());

  GrowableArray<HeapRegion*>* compaction_queue = collector()->serial_compaction_point()->regions();

  for (GrowableArrayIterator<HeapRegion*> it = compaction_queue->begin();

       it != compaction_queue->end();

       ++it) {

    compact_region(*it);

  }

}