/*

 * 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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#include "gc/g1/g1BarrierSet.hpp"

#include "gc/g1/g1CollectedHeap.hpp"

#include "gc/g1/g1CollectorState.hpp"

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

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

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

#include "runtime/orderAccess.hpp"

G1EvacStats* G1CollectedHeap::alloc_buffer_stats(InCSetState dest) {

  switch (dest.value()) {

    case InCSetState::Young:

      return &_survivor_evac_stats;

    case InCSetState::Old:

      return &_old_evac_stats;

    default:

      ShouldNotReachHere();

      return NULL; // Keep some compilers happy

  }

}

size_t G1CollectedHeap::desired_plab_sz(InCSetState dest) {

  size_t gclab_word_size = alloc_buffer_stats(dest)->desired_plab_sz(workers()->active_workers());

  // Prevent humongous PLAB sizes for two reasons:

  // * PLABs are allocated using a similar paths as oops, but should

  //   never be in a humongous region

  // * Allowing humongous PLABs needlessly churns the region free lists

  return MIN2(_humongous_object_threshold_in_words, gclab_word_size);

}

// Inline functions for G1CollectedHeap

// Return the region with the given index. It assumes the index is valid.

inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrm->at(index); }

// Return the region with the given index, or NULL if unmapped. It assumes the index is valid.

inline HeapRegion* G1CollectedHeap::region_at_or_null(uint index) const { return _hrm->at_or_null(index); }

inline HeapRegion* G1CollectedHeap::next_region_in_humongous(HeapRegion* hr) const {

  return _hrm->next_region_in_humongous(hr);

}

inline uint G1CollectedHeap::addr_to_region(HeapWord* addr) const {

  assert(is_in_reserved(addr),

         "Cannot calculate region index for address " PTR_FORMAT " that is outside of the heap [" PTR_FORMAT ", " PTR_FORMAT ")",

         p2i(addr), p2i(reserved_region().start()), p2i(reserved_region().end()));

  return (uint)(pointer_delta(addr, reserved_region().start(), sizeof(uint8_t)) >> HeapRegion::LogOfHRGrainBytes);

}

inline HeapWord* G1CollectedHeap::bottom_addr_for_region(uint index) const {

  return _hrm->reserved().start() + index * HeapRegion::GrainWords;

}

template <class T>

inline HeapRegion* G1CollectedHeap::heap_region_containing(const T addr) const {

  assert(addr != NULL, "invariant");

  assert(is_in_g1_reserved((const void*) addr),

         "Address " PTR_FORMAT " is outside of the heap ranging from [" PTR_FORMAT " to " PTR_FORMAT ")",

         p2i((void*)addr), p2i(g1_reserved().start()), p2i(g1_reserved().end()));

  return _hrm->addr_to_region((HeapWord*) addr);

}

template <class T>

inline HeapRegion* G1CollectedHeap::heap_region_containing_or_null(const T addr) const {

  assert(addr != NULL, "invariant");

  assert(is_in_g1_reserved((const void*) addr),

         "Address " PTR_FORMAT " is outside of the heap ranging from [" PTR_FORMAT " to " PTR_FORMAT ")",

         p2i((void*)addr), p2i(g1_reserved().start()), p2i(g1_reserved().end()));

  uint const region_idx = addr_to_region(addr);

  return region_at_or_null(region_idx);

}

inline void G1CollectedHeap::old_set_add(HeapRegion* hr) {

  _old_set.add(hr);

}

inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) {

  _old_set.remove(hr);

}

inline void G1CollectedHeap::archive_set_add(HeapRegion* hr) {

  _archive_set.add(hr);

}

// It dirties the cards that cover the block so that the post

// write barrier never queues anything when updating objects on this

// block. It is assumed (and in fact we assert) that the block

// belongs to a young region.

inline void

G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {

  assert_heap_not_locked();

  // Assign the containing region to containing_hr so that we don't

  // have to keep calling heap_region_containing() in the

  // asserts below.

  DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing(start);)

  assert(word_size > 0, "pre-condition");

  assert(containing_hr->is_in(start), "it should contain start");

  assert(containing_hr->is_young(), "it should be young");

  assert(!containing_hr->is_humongous(), "it should not be humongous");

  HeapWord* end = start + word_size;

  assert(containing_hr->is_in(end - 1), "it should also contain end - 1");

  MemRegion mr(start, end);

  card_table()->g1_mark_as_young(mr);

}

inline RefToScanQueue* G1CollectedHeap::task_queue(uint i) const {

  return _task_queues->queue(i);

}

inline bool G1CollectedHeap::is_marked_next(oop obj) const {

  return _cm->next_mark_bitmap()->is_marked((HeapWord*)obj);

}

inline bool G1CollectedHeap::is_in_cset(oop obj) {

  return is_in_cset((HeapWord*)obj);

}

inline bool G1CollectedHeap::is_in_cset(HeapWord* addr) {

  return _in_cset_fast_test.is_in_cset(addr);

}

bool G1CollectedHeap::is_in_cset(const HeapRegion* hr) {

  return _in_cset_fast_test.is_in_cset(hr);

}

bool G1CollectedHeap::is_in_cset_or_humongous(const oop obj) {

  return _in_cset_fast_test.is_in_cset_or_humongous((HeapWord*)obj);

}

InCSetState G1CollectedHeap::in_cset_state(const oop obj) {

  return _in_cset_fast_test.at((HeapWord*)obj);

}

void G1CollectedHeap::register_humongous_region_with_cset(uint index) {

  _in_cset_fast_test.set_humongous(index);

}

#ifndef PRODUCT

// Support for G1EvacuationFailureALot

inline bool

G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool for_young_gc,

                                                     bool during_initial_mark,

                                                     bool mark_or_rebuild_in_progress) {

  bool res = false;

  if (mark_or_rebuild_in_progress) {

    res |= G1EvacuationFailureALotDuringConcMark;

  }

  if (during_initial_mark) {

    res |= G1EvacuationFailureALotDuringInitialMark;

  }

  if (for_young_gc) {

    res |= G1EvacuationFailureALotDuringYoungGC;

  } else {

    // GCs are mixed

    res |= G1EvacuationFailureALotDuringMixedGC;

  }

  return res;

}

inline void

G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {

  if (G1EvacuationFailureALot) {

    // Note we can't assert that _evacuation_failure_alot_for_current_gc

    // is clear here. It may have been set during a previous GC but that GC

    // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to

    // trigger an evacuation failure and clear the flags and and counts.

    // Check if we have gone over the interval.

    const size_t gc_num = total_collections();

    const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;

    _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);

    // Now check if G1EvacuationFailureALot is enabled for the current GC type.

    const bool in_young_only_phase = collector_state()->in_young_only_phase();

    const bool in_initial_mark_gc = collector_state()->in_initial_mark_gc();

    const bool mark_or_rebuild_in_progress = collector_state()->mark_or_rebuild_in_progress();

    _evacuation_failure_alot_for_current_gc &=

      evacuation_failure_alot_for_gc_type(in_young_only_phase,

                                          in_initial_mark_gc,

                                          mark_or_rebuild_in_progress);

  }

}

inline bool G1CollectedHeap::evacuation_should_fail() {

  if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {

    return false;

  }

  // G1EvacuationFailureALot is in effect for current GC

  // Access to _evacuation_failure_alot_count is not atomic;

  // the value does not have to be exact.

  if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {

    return false;

  }

  _evacuation_failure_alot_count = 0;

  return true;

}

inline void G1CollectedHeap::reset_evacuation_should_fail() {

  if (G1EvacuationFailureALot) {

    _evacuation_failure_alot_gc_number = total_collections();

    _evacuation_failure_alot_count = 0;

    _evacuation_failure_alot_for_current_gc = false;

  }

}

#endif  // #ifndef PRODUCT

inline bool G1CollectedHeap::is_in_young(const oop obj) {

  if (obj == NULL) {

    return false;

  }

  return heap_region_containing(obj)->is_young();

}

inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {

  if (obj == NULL) {

    return false;

  }

  return is_obj_dead(obj, heap_region_containing(obj));

}

inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {

  if (obj == NULL) {

    return false;

  }

  return is_obj_ill(obj, heap_region_containing(obj));

}

inline bool G1CollectedHeap::is_obj_dead_full(const oop obj, const HeapRegion* hr) const {

   return !is_marked_next(obj) && !hr->is_archive();

}

inline bool G1CollectedHeap::is_obj_dead_full(const oop obj) const {

    return is_obj_dead_full(obj, heap_region_containing(obj));

}

inline void G1CollectedHeap::set_humongous_reclaim_candidate(uint region, bool value) {

  assert(_hrm->at(region)->is_starts_humongous(), "Must start a humongous object");

  _humongous_reclaim_candidates.set_candidate(region, value);

}

inline bool G1CollectedHeap::is_humongous_reclaim_candidate(uint region) {

  assert(_hrm->at(region)->is_starts_humongous(), "Must start a humongous object");

  return _humongous_reclaim_candidates.is_candidate(region);

}

inline void G1CollectedHeap::set_humongous_is_live(oop obj) {

  uint region = addr_to_region((HeapWord*)obj);

  // Clear the flag in the humongous_reclaim_candidates table.  Also

  // reset the entry in the _in_cset_fast_test table so that subsequent references

  // to the same humongous object do not go into the slow path again.

  // This is racy, as multiple threads may at the same time enter here, but this

  // is benign.

  // During collection we only ever clear the "candidate" flag, and only ever clear the

  // entry in the in_cset_fast_table.

  // We only ever evaluate the contents of these tables (in the VM thread) after

  // having synchronized the worker threads with the VM thread, or in the same

  // thread (i.e. within the VM thread).

  if (is_humongous_reclaim_candidate(region)) {

    set_humongous_reclaim_candidate(region, false);

    _in_cset_fast_test.clear_humongous(region);

  }

}