/*

 * Copyright (c) 2014, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "gc/g1/g1Allocator.inline.hpp"

#include "gc/g1/g1AllocRegion.inline.hpp"

#include "gc/g1/g1EvacStats.inline.hpp"

#include "gc/g1/g1EvacuationInfo.hpp"

#include "gc/g1/g1CollectedHeap.inline.hpp"

#include "gc/g1/g1NUMA.hpp"

#include "gc/g1/g1Policy.hpp"

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

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

#include "gc/g1/heapRegionType.hpp"

#include "utilities/align.hpp"

G1Allocator::G1Allocator(G1CollectedHeap* heap) :

  _g1h(heap),

  _numa(heap->numa()),

  _survivor_is_full(false),

  _old_is_full(false),

  _num_alloc_regions(_numa->num_active_nodes()),

  _mutator_alloc_regions(NULL),

  _old_gc_alloc_region(heap->alloc_buffer_stats(G1HeapRegionAttr::Old)),

  _retained_old_gc_alloc_region(NULL) {

  _mutator_alloc_regions = NEW_C_HEAP_ARRAY(MutatorAllocRegion, _num_alloc_regions, mtGC);

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

    ::new(_mutator_alloc_regions + i) MutatorAllocRegion(i);

  }

}

G1Allocator::~G1Allocator() {

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

    _mutator_alloc_regions[i].~MutatorAllocRegion();

  }

  FREE_C_HEAP_ARRAY(MutatorAllocRegion, _mutator_alloc_regions);

}

#ifdef ASSERT

bool G1Allocator::has_mutator_alloc_region() {

  uint node_index = current_node_index();

  return mutator_alloc_region(node_index)->get() != NULL;

}

#endif

void G1Allocator::init_mutator_alloc_regions() {

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

    assert(mutator_alloc_region(i)->get() == NULL, "pre-condition");

    mutator_alloc_region(i)->init();

  }

}

void G1Allocator::release_mutator_alloc_regions() {

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

    mutator_alloc_region(i)->release();

    assert(mutator_alloc_region(i)->get() == NULL, "post-condition");

  }

}

bool G1Allocator::is_retained_old_region(HeapRegion* hr) {

  return _retained_old_gc_alloc_region == hr;

}

void G1Allocator::reuse_retained_old_region(G1EvacuationInfo& evacuation_info,

                                            OldGCAllocRegion* old,

                                            HeapRegion** retained_old) {

  HeapRegion* retained_region = *retained_old;

  *retained_old = NULL;

  assert(retained_region == NULL || !retained_region->is_archive(),

         "Archive region should not be alloc region (index %u)", retained_region->hrm_index());

  // We will discard the current GC alloc region if:

  // a) it's in the collection set (it can happen!),

  // b) it's already full (no point in using it),

  // c) it's empty (this means that it was emptied during

  // a cleanup and it should be on the free list now), or

  // d) it's humongous (this means that it was emptied

  // during a cleanup and was added to the free list, but

  // has been subsequently used to allocate a humongous

  // object that may be less than the region size).

  if (retained_region != NULL &&

      !retained_region->in_collection_set() &&

      !(retained_region->top() == retained_region->end()) &&

      !retained_region->is_empty() &&

      !retained_region->is_humongous()) {

    // The retained region was added to the old region set when it was

    // retired. We have to remove it now, since we don't allow regions

    // we allocate to in the region sets. We'll re-add it later, when

    // it's retired again.

    _g1h->old_set_remove(retained_region);

    old->set(retained_region);

    _g1h->hr_printer()->reuse(retained_region);

    evacuation_info.set_alloc_regions_used_before(retained_region->used());

  }

}

void G1Allocator::init_gc_alloc_regions(G1EvacuationInfo& evacuation_info) {

  assert_at_safepoint_on_vm_thread();

  _survivor_is_full = false;

  _old_is_full = false;

  _old_gc_alloc_region.init();

  reuse_retained_old_region(evacuation_info,

                            &_old_gc_alloc_region,

                            &_retained_old_gc_alloc_region);

}

void G1Allocator::release_gc_alloc_regions(G1EvacuationInfo& evacuation_info) {

                                         old_gc_alloc_region()->count());

  // If we have an old GC alloc region to release, we'll save it in

  // _retained_old_gc_alloc_region. If we don't

  // _retained_old_gc_alloc_region will become NULL. This is what we

  // want either way so no reason to check explicitly for either

  // condition.

  _retained_old_gc_alloc_region = old_gc_alloc_region()->release();

}

void G1Allocator::abandon_gc_alloc_regions() {

  assert(old_gc_alloc_region()->get() == NULL, "pre-condition");

  _retained_old_gc_alloc_region = NULL;

}

bool G1Allocator::survivor_is_full() const {

  return _survivor_is_full;

}

bool G1Allocator::old_is_full() const {

  return _old_is_full;

}

void G1Allocator::set_survivor_full() {

  _survivor_is_full = true;

}

void G1Allocator::set_old_full() {

  _old_is_full = true;

}

size_t G1Allocator::unsafe_max_tlab_alloc() {

  // Return the remaining space in the cur alloc region, but not less than

  // the min TLAB size.

  // Also, this value can be at most the humongous object threshold,

  // since we can't allow tlabs to grow big enough to accommodate

  // humongous objects.

  uint node_index = current_node_index();

  HeapRegion* hr = mutator_alloc_region(node_index)->get();

  size_t max_tlab = _g1h->max_tlab_size() * wordSize;

  if (hr == NULL) {

    return max_tlab;

  } else {

    return MIN2(MAX2(hr->free(), (size_t) MinTLABSize), max_tlab);

  }

}

size_t G1Allocator::used_in_alloc_regions() {

  assert(Heap_lock->owner() != NULL, "Should be owned on this thread's behalf.");

  size_t used = 0;

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

    used += mutator_alloc_region(i)->used_in_alloc_regions();

  }

  return used;

}

HeapWord* G1Allocator::par_allocate_during_gc(G1HeapRegionAttr dest,

  size_t temp = 0;

  assert(result == NULL || temp == word_size,

         "Requested " SIZE_FORMAT " words, but got " SIZE_FORMAT " at " PTR_FORMAT,

         word_size, temp, p2i(result));

  return result;

}

HeapWord* G1Allocator::par_allocate_during_gc(G1HeapRegionAttr dest,

                                              size_t min_word_size,

                                              size_t desired_word_size,

  switch (dest.type()) {

    case G1HeapRegionAttr::Young:

    case G1HeapRegionAttr::Old:

      return old_attempt_allocation(min_word_size, desired_word_size, actual_word_size);

    default:

      ShouldNotReachHere();

      return NULL; // Keep some compilers happy

  }

}

HeapWord* G1Allocator::survivor_attempt_allocation(size_t min_word_size,

                                                   size_t desired_word_size,

  assert(!_g1h->is_humongous(desired_word_size),

         "we should not be seeing humongous-size allocations in this path");

  if (result == NULL && !survivor_is_full()) {

    MutexLocker x(FreeList_lock, Mutex::_no_safepoint_check_flag);

    if (result == NULL) {

      set_survivor_full();

    }

  }

  if (result != NULL) {

    _g1h->dirty_young_block(result, *actual_word_size);

  }

  return result;

}

HeapWord* G1Allocator::old_attempt_allocation(size_t min_word_size,

                                              size_t desired_word_size,

                                              size_t* actual_word_size) {

  assert(!_g1h->is_humongous(desired_word_size),

         "we should not be seeing humongous-size allocations in this path");

  HeapWord* result = old_gc_alloc_region()->attempt_allocation(min_word_size,

                                                               desired_word_size,

                                                               actual_word_size);

  if (result == NULL && !old_is_full()) {

    MutexLocker x(FreeList_lock, Mutex::_no_safepoint_check_flag);

    result = old_gc_alloc_region()->attempt_allocation_locked(min_word_size,

                                                              desired_word_size,

                                                              actual_word_size);

    if (result == NULL) {

      set_old_full();

    }

  }

  return result;

}

uint G1PLABAllocator::calc_survivor_alignment_bytes() {

  assert(SurvivorAlignmentInBytes >= ObjectAlignmentInBytes, "sanity");

  if (SurvivorAlignmentInBytes == ObjectAlignmentInBytes) {

    // No need to align objects in the survivors differently, return 0

    // which means "survivor alignment is not used".

    return 0;

  } else {

    assert(SurvivorAlignmentInBytes > 0, "sanity");

    return SurvivorAlignmentInBytes;

  }

}

G1PLABAllocator::G1PLABAllocator(G1Allocator* allocator) :

  _g1h(G1CollectedHeap::heap()),

  _allocator(allocator),

  _survivor_alignment_bytes(calc_survivor_alignment_bytes()) {

    _direct_allocated[state] = 0;

  }

}

bool G1PLABAllocator::may_throw_away_buffer(size_t const allocation_word_sz, size_t const buffer_size) const {

  return (allocation_word_sz * 100 < buffer_size * ParallelGCBufferWastePct);

}

HeapWord* G1PLABAllocator::allocate_direct_or_new_plab(G1HeapRegionAttr dest,

                                                       size_t word_sz,

  size_t plab_word_size = _g1h->desired_plab_sz(dest);

  size_t required_in_plab = PLAB::size_required_for_allocation(word_sz);

  // Only get a new PLAB if the allocation fits and it would not waste more than

  // ParallelGCBufferWastePct in the existing buffer.

  if ((required_in_plab <= plab_word_size) &&

    may_throw_away_buffer(required_in_plab, plab_word_size)) {

    alloc_buf->retire();

    size_t actual_plab_size = 0;

    HeapWord* buf = _allocator->par_allocate_during_gc(dest,

                                                       required_in_plab,

                                                       plab_word_size,

    assert(buf == NULL || ((actual_plab_size >= required_in_plab) && (actual_plab_size <= plab_word_size)),

           "Requested at minimum " SIZE_FORMAT ", desired " SIZE_FORMAT " words, but got " SIZE_FORMAT " at " PTR_FORMAT,

           required_in_plab, plab_word_size, actual_plab_size, p2i(buf));

    if (buf != NULL) {

      alloc_buf->set_buf(buf, actual_plab_size);

      HeapWord* const obj = alloc_buf->allocate(word_sz);

      assert(obj != NULL, "PLAB should have been big enough, tried to allocate "

                          SIZE_FORMAT " requiring " SIZE_FORMAT " PLAB size " SIZE_FORMAT,

                          word_sz, required_in_plab, plab_word_size);

      return obj;

    }

    // Otherwise.

    *plab_refill_failed = true;

  }

  // Try direct allocation.

  if (result != NULL) {

    _direct_allocated[dest.type()] += word_sz;

  }

  return result;

}

}

void G1PLABAllocator::flush_and_retire_stats() {

    }

  }

}

size_t G1PLABAllocator::waste() const {

  size_t result = 0;

    }

  }

  return result;

}

size_t G1PLABAllocator::undo_waste() const {

  size_t result = 0;

    }

  }

  return result;

}

bool G1ArchiveAllocator::_archive_check_enabled = false;

G1ArchiveRegionMap G1ArchiveAllocator::_closed_archive_region_map;

G1ArchiveRegionMap G1ArchiveAllocator::_open_archive_region_map;

G1ArchiveAllocator* G1ArchiveAllocator::create_allocator(G1CollectedHeap* g1h, bool open) {

  // Create the archive allocator, and also enable archive object checking

  // in mark-sweep, since we will be creating archive regions.

  G1ArchiveAllocator* result =  new G1ArchiveAllocator(g1h, open);

  enable_archive_object_check();

  return result;

}

bool G1ArchiveAllocator::alloc_new_region() {

  // Allocate the highest free region in the reserved heap,

  // and add it to our list of allocated regions. It is marked

  // archive and added to the old set.

  HeapRegion* hr = _g1h->alloc_highest_free_region();

  if (hr == NULL) {

    return false;

  }

  assert(hr->is_empty(), "expected empty region (index %u)", hr->hrm_index());

  if (_open) {

    hr->set_open_archive();

  } else {

    hr->set_closed_archive();

  }

  _g1h->policy()->remset_tracker()->update_at_allocate(hr);

  _g1h->archive_set_add(hr);

  _g1h->hr_printer()->alloc(hr);

  _allocated_regions.append(hr);

  _allocation_region = hr;

  // Set up _bottom and _max to begin allocating in the lowest

  // min_region_size'd chunk of the allocated G1 region.

  _bottom = hr->bottom();

  _max = _bottom + HeapRegion::min_region_size_in_words();

  // Tell mark-sweep that objects in this region are not to be marked.

  set_range_archive(MemRegion(_bottom, HeapRegion::GrainWords), _open);

  // Since we've modified the old set, call update_sizes.

  _g1h->g1mm()->update_sizes();

  return true;

}

HeapWord* G1ArchiveAllocator::archive_mem_allocate(size_t word_size) {

  assert(word_size != 0, "size must not be zero");

  if (_allocation_region == NULL) {

    if (!alloc_new_region()) {

      return NULL;

    }

  }

  HeapWord* old_top = _allocation_region->top();

  assert(_bottom >= _allocation_region->bottom(),

         "inconsistent allocation state: " PTR_FORMAT " < " PTR_FORMAT,

         p2i(_bottom), p2i(_allocation_region->bottom()));

  assert(_max <= _allocation_region->end(),

         "inconsistent allocation state: " PTR_FORMAT " > " PTR_FORMAT,

         p2i(_max), p2i(_allocation_region->end()));

  assert(_bottom <= old_top && old_top <= _max,

         "inconsistent allocation state: expected "

         PTR_FORMAT " <= " PTR_FORMAT " <= " PTR_FORMAT,

         p2i(_bottom), p2i(old_top), p2i(_max));

  // Allocate the next word_size words in the current allocation chunk.

  // If allocation would cross the _max boundary, insert a filler and begin

  // at the base of the next min_region_size'd chunk. Also advance to the next

  // chunk if we don't yet cross the boundary, but the remainder would be too

  // small to fill.

  HeapWord* new_top = old_top + word_size;

  size_t remainder = pointer_delta(_max, new_top);

  if ((new_top > _max) ||

      ((new_top < _max) && (remainder < CollectedHeap::min_fill_size()))) {

    if (old_top != _max) {

      size_t fill_size = pointer_delta(_max, old_top);