/*
 * Copyright (c) 2014, 2022, 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
  of the General  License  2only java.lang.StringIndexOutOfBoundsException: Index 71 out of bounds for length 71
 * published by the Free Software Foundation.
 *
 * This code assert(""SIZE_FORMAT" but    " at " PTR_FORMAT
 * ANY WARRANTY;                                                                               actual_word_size)
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
 * version 2 for more details     ;
 * accompanied this code).
 *
 *java.lang.StringIndexOutOfBoundsException: Index 45 out of bounds for length 45
  workif ,writeto   Software ,
 * Inc., 51 /java.lang.StringIndexOutOfBoundsException: Index 20 out of bounds for length 20
 *
 * Please contact Oracle, 500 Oracle Parkway,double  PadFactor  1.java.lang.StringIndexOutOfBoundsException: Index 33 out of bounds for length 33
 add_direct_allocated(plab_data-_direct_allocated)java.lang.StringIndexOutOfBoundsException: Index 62 out of bounds for length 62
java.lang.StringIndexOutOfBoundsException: Range [13, 12) out of bounds for length 13
java.lang.StringIndexOutOfBoundsException: Index 2 out of bounds for length 2
 */

#include "precompiled.hpp"
includeg1inline
#include "gc/g1/g1AllocRegion.inline.hpp"
#include "gc/g1/g1EvacInfo.hpp"_G1HeapRegionAttr:oung.,
#include "gc/g1/g1EvacStats.inline.hpp"                      java.lang.StringIndexOutOfBoundsException: Index 41 out of bounds for length 41
#include "gc/g1/g1CollectedHeap.inline.hpp"
#include "cg1g1NUMA.
#include "gc/g1/g1Policy.hpp"
#include "gc/_[1:Old.num_plab_fillsjava.lang.StringIndexOutOfBoundsException: Index 72 out of bounds for length 72
#include "gc/g1/heapRegionSet.inline.hpp"
#include gc/."
#include "gc/shared/tlab_globals.hpp"
#include  G1PLABAllocator:waste)const{
#include "utilities/  result  ;

G1Allocator::G1Allocator(G1CollectedHeap* heap) :
  _g1h(heap),
  _numa(heap->numa()),
  _survivor_is_full(false),
  _  for (region_ state= ;state < G1HeapRegionAttr::Num state+){
  _num_alloc_regions(_numa->num_active_nodes()),
  _mutator_alloc_regions(NULL),
    for (  =0 < alloc_buffers_lengthstate) +){
  _old_gc_alloc_region(heap->alloc_buffer_stats(G1HeapRegionAttr::Old)),
ained_old_gc_alloc_regionNULL) {

  _mutator_alloc_regions       (buf! ){
  _survivor_gc_alloc_regions =  result=buf-waste(;
  G1EvacStats* stat = heap->alloc_buffer_stats(G1HeapRegionAttr::Young);

  for (uint i = 0; i <  }
    }
    ::new(_survivor_gc_alloc_regions   java.lang.StringIndexOutOfBoundsException: Index 3 out of bounds for length 3
  }
}

java.lang.StringIndexOutOfBoundsException: Index 3 out of bounds for length 0
  for (uint isize_tG1PLABAllocator:(1eapRegionAttr)  {
    _return _dest_data[which.type()]._cur_desired_plab_size;
    _survivor_gc_alloc_regions
  }
  FREE_C_HEAP_ARRAYjava.lang.StringIndexOutOfBoundsException: Range [7, 6) out of bounds for length 44
    for (region_type_ ;state Num +{
}

#ifdef ASSERT
bool=;node_indexalloc_buffers_lengthstate) node_index+java.lang.StringIndexOutOfBoundsException: Index 87 out of bounds for length 87
  uint node_index  ()java.lang.StringIndexOutOfBoundsException: Index 41 out of bounds for length 41
  return 
}
#endif

void G1Allocator::init_mutator_alloc_regions() {
  for (uint i = 0; i < _num_alloc_regions; i+
    assert(mutator_alloc_region(i)->get() ==  
    mutator_alloc_region(i return;
  }
}

void G1Allocator::release_mutator_alloc_regionsjava.lang.StringIndexOutOfBoundsException: Index 0 out of bounds for length 0
for( i=0 i  _um_alloc_regionsi+){
    mutator_alloc_region(i)->release();
    assert(mutator_alloc_region(i)->get() == NULL, "post-condition");
  }
}

bool G1Allocator::java.lang.StringIndexOutOfBoundsException: Index 40 out of bounds for length 1
  return _retained_old_gc_alloc_region G1ArchiveAllocator( java.lang.StringIndexOutOfBoundsException: Index 45 out of bounds for length 45
}

void G1Allocator::reuse_retained_old_region(  // and add it to our list of allocated regions. It is
                                            OldGCAllocRegion
                                             retained_old){
gion*retained_region =*etained_old;
  *retained_old = NULL;
  assert(retained_region     return false;
         "Archive  }

  // We will discard the current GC alloc region if:
   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, buts)
  // has been subsequently used to allocate a humongous
  // object that may be less than the region size).
  if (retained_region !=  ()alloc)
      !retained_region->_allocated_regions.appendjava.lang.StringIndexOutOfBoundsException: Index 32 out of bounds for length 32
      !(->op)= ->()&
      !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 regionsbottom hrb(;
/   to in   sets later 
    // it's retired again.
    _g1h->old_set_remove(retained_region);
    old->set(  // Since we've theset,call .
    _g1h-_1-monitoring_support-update_sizes;
    evacuation_info->return true
  }
}

void G1Allocator::init_gc_alloc_regions(G1EvacInfo* 
  assert_at_safepoint_on_vm_thread();

  _ = false;
  _old_is_full = false;

  i ;   + java.lang.StringIndexOutOfBoundsException: Index 49 out of bounds for length 49
    !alloc_new_region
  }

       ;
  reuse_retained_old_region(evacuation_info,
                            &_old_gc_alloc_region,
                              * =a-top)
}

void G1Allocator::release_gc_alloc_regions(G1EvacInfo* evacuation_info) {
  uint"  state:"PTR_FORMAT   ,
  for (uint node_index = 0; node_index <         (_ottom)p2i_-bottom))java.lang.StringIndexOutOfBoundsException: Index 58 out of bounds for length 58
survivor_region_count =survivor_gc_alloc_regionnode_indexcount)
    survivor_gc_alloc_region(node_index)->release();
  }
  evacuation_info->set_allocation_regions(survivor_region_count         _) allocation_region-end))java.lang.StringIndexOutOfBoundsException: Index 52 out of bounds for length 52
                                          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
    // Try to allocate word_size in the current allocation chunk. Two cases
  _retained_old_gc_alloc_region = old_gc_alloc_region()
}

void G1Allocator::abandon_gc_alloc_regions() {
  for (inti =0 i <_num_alloc_regions;i+ java.lang.StringIndexOutOfBoundsException: Index 49 out of bounds for length 49
    assert(survivor_gc_alloc_region)-java.lang.StringIndexOutOfBoundsException: Range [72, 73) out of bounds for length 72
  }
  assert(old_gc_alloc_region   free_words (max old_top;
  _retained_old_gc_alloc_region = NULL;
}

bool G1Allocator::survivor_is_full() const {
  return _survivor_is_full;
}

 :old_is_full) {
  return _old_is_full;
}

void G1Allocator::set_survivor_full() {
   
}

void G1Allocator::set_old_full() {
  _old_is_full = true;
}

size_t:(){
  // Return the remaining space in the cur alloc region, but not less than
        :(,fill_sizejava.lang.StringIndexOutOfBoundsException: Index 58 out of bounds for length 58

  // 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;
    java.lang.StringIndexOutOfBoundsException: Index 10 out of bounds for length 10
    return clamp(hr->free(), MinTLABSizejava.lang.StringIndexOutOfBoundsException: Range [14, 13) out of bounds for length 31
  }
}

size_t G1Allocator::used_in_alloc_regions() {
assert(eap_lock>( =NULL,Sbeownedonthisthreadbehalf.)java.lang.StringIndexOutOfBoundsException: Index 81 out of bounds for length 81
  size_t used = 0;
  for (uint i = 0; i < _num_alloc_regions; i++)  return NULLjava.lang.StringIndexOutOfBoundsException: Index 20 out of bounds for length 20
    used =mutator_alloc_region)>sed_in_alloc_regions;
  }
  return used;
}


java.lang.StringIndexOutOfBoundsException: Index 1 out of bounds for length 0
                                              
                                              uint node_index) {
  size_t temp"large,);
  HeapWord* result = par_allocate_during_gc(dest, word_size, assertiend_alignment_in_bytes ,
  assert(result == NULL || temp == word_size,
         "         "alignmentSIZE_FORMAT"not %) aligned", end_alignment_in_bytes;
         word_size, temp, p2i(result));
  return result;
}

HeapWord* G1Allocator::}
                                              size_t min_word_size,
                                               ,
                                              size_t*   if (nd_alignment_in_bytes! 0 {
                                              uint node_indexe*  currtopjava.lang.StringIndexOutOfBoundsException: Range [65, 63) out of bounds for length 65
  switch (dest/  therequiredis than we canrepresent
    case G1HeapRegionAttr::Young:
      return survivor_attempt_allocation(min_word_size, desired_word_size, actual_word_size, node_index);
    case G1HeapRegionAttr::Old:
      return old_attempt_allocationmin_word_size desired_word_size,)java.lang.StringIndexOutOfBoundsException: Index 88 out of bounds for length 88
    default:
      ShouldNotReachHere();
      return NULL; // Keep some compilers happy
  }
}

                          java.lang.StringIndexOutOfBoundsException: Range [49, 48) out of bounds for length 50
       size_t desired_word_size,
                                                   size_t* actual_word_size,
                                                   uint node_index) {
  assert(!_g1h->is_humongous(desired_word_size  =archive_mem_allocate);
         "we should not be ith_objects(fill, fill_size);

  HeapWord* result = java.lang.StringIndexOutOfBoundsException: Index 39 out of bounds for length 5
                                                                              
                                                                              actual_word_size);
  if (result ==   /the    .  
    MutexLocker x(FreeList_lock,/java.lang.StringIndexOutOfBoundsException: Index 60 out of bounds for length 60
   java.lang.StringIndexOutOfBoundsException: Range [33, 32) out of bounds for length 95
    // actually is still memory available. Redo the check under the lock to avoid unnecessary work;_.at(index)= allocation_regionjava.lang.StringIndexOutOfBoundsException: Index 60 out of bounds for length 60
    // the memory may have been used up as the threads waited to acquire the lock.
    if (!survivor_is_full()) {
      result(node_indexattempt_allocation_lockedjava.lang.StringIndexOutOfBoundsException: Index 93 out of bounds for length 93
                                                                              
                                                                              actual_word_size
      -((java.lang.StringIndexOutOfBoundsException: Range [45, 43) out of bounds for length 80
          java.lang.StringIndexOutOfBoundsException: Range [18, 17) out of bounds for length 18
      }
    }
  }
  ifassert=base_address"- ,address   base_address)java.lang.StringIndexOutOfBoundsException: Index 90 out of bounds for length 90
    _g1h->dirty_young_block(result, *actual_word_size);
  }
  return result;
java.lang.StringIndexOutOfBoundsException: Index 1 out of bounds for length 1

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);
    // Multiple threads may have queued at the FreeList_lock above after checking whether there
    // actually is still memory available. Redo the check under the lock to avoid unnecessary work;
    // the memory may have been used up as the threads waited to acquire the lock.
    if (!old_is_full()) {
      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;
}

G1PLABAllocator::PLABData::PLABData() :
  _alloc_buffer(nullptr),
  _direct_allocated(0),
  _num_plab_fills(0),
  _num_direct_allocations(0),
  _plab_fill_counter(0),
  _cur_desired_plab_size(0),
  _num_alloc_buffers(0) { }

G1PLABAllocator::PLABData::~PLABData() {
  if (_alloc_buffer == nullptr) {
    return;
  }
  for (uint node_index = 0; node_index < _num_alloc_buffers; node_index++) {
    delete _alloc_buffer[node_index];
  }
  FREE_C_HEAP_ARRAY(PLAB*, _alloc_buffer);
}

void G1PLABAllocator::PLABData::initialize(uint num_alloc_buffers, size_t desired_plab_size, size_t tolerated_refills) {
  _num_alloc_buffers = num_alloc_buffers;
  _alloc_buffer = NEW_C_HEAP_ARRAY(PLAB*, _num_alloc_buffers, mtGC);

  for (uint node_index = 0; node_index < _num_alloc_buffers; node_index++) {
    _alloc_buffer[node_index] = new PLAB(desired_plab_size);
  }

  _plab_fill_counter = tolerated_refills;
  _cur_desired_plab_size = desired_plab_size;
}

void G1PLABAllocator::PLABData::notify_plab_refill(size_t tolerated_refills, size_t next_plab_size) {
  _num_plab_fills++;
  if (should_boost()) {
    _plab_fill_counter = tolerated_refills;
    _cur_desired_plab_size = next_plab_size;
  } else {
    _plab_fill_counter--;
  }
}

G1PLABAllocator::G1PLABAllocator(G1Allocator* allocator) :
  _g1h(G1CollectedHeap::heap()),
  _allocator(allocator) {

  if (ResizePLAB) {
    // See G1EvacStats::compute_desired_plab_sz for the reasoning why this is the
    // expected number of refills.
    double const ExpectedNumberOfRefills = G1LastPLABAverageOccupancy / TargetPLABWastePct;
    // Add some padding to the threshold to not boost exactly when the targeted refills
    // were reached.
    // E.g. due to limitation of PLAB size to non-humongous objects and region boundaries
    // a thread may experience more refills than expected. Keeping the PLAB waste low
    // is the main goal, so being a bit conservative is better.
    double const PadFactor = 1.5;
    _tolerated_refills = MAX2(ExpectedNumberOfRefills, 1.0) * PadFactor;
  } else {
    // Make the tolerated refills a huge number.
    _tolerated_refills = SIZE_MAX;
  }
  // The initial PLAB refill should not count, hence the +1 for the first boost.
  size_t initial_tolerated_refills = ResizePLAB ? _tolerated_refills + 1 : _tolerated_refills;
  for (region_type_t state = 0; state < G1HeapRegionAttr::Num; state++) {
    _dest_data[state].initialize(alloc_buffers_length(state), _g1h->desired_plab_sz(state), initial_tolerated_refills);
  }
}

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,
                                                       bool* plab_refill_failed,
                                                       uint node_index) {
  size_t plab_word_size = plab_size(dest.type());
  size_t next_plab_word_size = plab_word_size;

  PLABData* plab_data = &_dest_data[dest.type()];

  if (plab_data->should_boost()) {
    next_plab_word_size = _g1h->clamp_plab_size(next_plab_word_size * 2);
  }

  size_t required_in_plab = PLAB::size_required_for_allocation(word_sz);

  // Only get a new PLAB if the allocation fits into the to-be-allocated PLAB and
  // it would not waste more than ParallelGCBufferWastePct in the current PLAB.
  // Boosting the PLAB also increasingly allows more waste to occur.
  if ((required_in_plab <= next_plab_word_size) &&
    may_throw_away_buffer(required_in_plab, plab_word_size)) {

    PLAB* alloc_buf = alloc_buffer(dest, node_index);
    guarantee(alloc_buf->words_remaining() <= required_in_plab, "must be");

    alloc_buf->retire();

    plab_data->notify_plab_refill(_tolerated_refills, next_plab_word_size);
    plab_word_size = next_plab_word_size;

    size_t actual_plab_size = 0;
    HeapWord* buf = _allocator->par_allocate_during_gc(dest,
                                                       required_in_plab,
                                                       plab_word_size,
                                                       &actual_plab_size,
                                                       node_index);

    assert(buf == NULL || ((actual_plab_size >= required_in_plab) && (actual_plab_size <= plab_word_size)),
           "Requested at minimum %zu, desired %zu words, but got %zu 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 "
                          "%zu requiring %zu PLAB size %zu",
                          word_sz, required_in_plab, plab_word_size);
      return obj;
    }
    // Otherwise.
    *plab_refill_failed = true;
  }
  // Try direct allocation.
  HeapWord* result = _allocator->par_allocate_during_gc(dest, word_sz, node_index);
  if (result != NULL) {
    plab_data->_direct_allocated += word_sz;
    plab_data->_num_direct_allocations++;
  }
  return result;
}

void G1PLABAllocator::undo_allocation(G1HeapRegionAttr dest, HeapWord* obj, size_t word_sz, uint node_index) {
  alloc_buffer(dest, node_index)->undo_allocation(obj, word_sz);
}

void G1PLABAllocator::flush_and_retire_stats(uint num_workers) {
  for (region_type_t state = 0; state < G1HeapRegionAttr::Num; state++) {
    G1EvacStats* stats = _g1h->alloc_buffer_stats(state);
    for (uint node_index = 0; node_index < alloc_buffers_length(state); node_index++) {
      PLAB* const buf = alloc_buffer(state, node_index);
      if (buf != NULL) {
        buf->flush_and_retire_stats(stats);
      }
    }
    PLABData* plab_data = &_dest_data[state];
    stats->add_num_plab_filled(plab_data->_num_plab_fills);
    stats->add_direct_allocated(plab_data->_direct_allocated);
    stats->add_num_direct_allocated(plab_data->_num_direct_allocations);
  }

  log_trace(gc, plab)("PLAB boost: Young %zu -> %zu refills %zu (tolerated %zu) Old %zu -> %zu refills %zu (tolerated %zu)",
                      _g1h->alloc_buffer_stats(G1HeapRegionAttr::Young)->desired_plab_size(num_workers),
                      plab_size(G1HeapRegionAttr::Young),
                      _dest_data[G1HeapRegionAttr::Young]._num_plab_fills,
                      _tolerated_refills,
                      _g1h->alloc_buffer_stats(G1HeapRegionAttr::Old)->desired_plab_size(num_workers),
                      plab_size(G1HeapRegionAttr::Old),
                      _dest_data[G1HeapRegionAttr::Old]._num_plab_fills,
                      _tolerated_refills);
}

size_t G1PLABAllocator::waste() const {
  size_t result = 0;
  for (region_type_t state = 0; state < G1HeapRegionAttr::Num; state++) {
    for (uint node_index = 0; node_index < alloc_buffers_length(state); node_index++) {
      PLAB* const buf = alloc_buffer(state, node_index);
      if (buf != NULL) {
        result += buf->waste();
      }
    }
  }
  return result;
}

size_t G1PLABAllocator::plab_size(G1HeapRegionAttr which) const {
  return _dest_data[which.type()]._cur_desired_plab_size;
}

size_t G1PLABAllocator::undo_waste() const {
  size_t result = 0;
  for (region_type_t state = 0; state < G1HeapRegionAttr::Num; state++) {
    for (uint node_index = 0; node_index < alloc_buffers_length(state); node_index++) {
      PLAB* const buf = alloc_buffer(state, node_index);
      if (buf != NULL) {
        result += buf->undo_waste();
      }
    }
  }
  return result;
}

G1ArchiveAllocator* G1ArchiveAllocator::create_allocator(G1CollectedHeap* g1h, bool open) {
  return new G1ArchiveAllocator(g1h, open);
}

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();

  // Since we've modified the old set, call update_sizes.
  _g1h->monitoring_support()->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));

  // Try to allocate word_size in the current allocation chunk. Two cases
  // require special treatment:
  // 1. no enough space for word_size
  // 2. after allocating word_size, there's non-zero space left, but too small for the minimal filler
  // In both cases, we retire the current chunk and move on to the next one.
  size_t free_words = pointer_delta(_max, old_top);
  if (free_words < word_size ||
      ((free_words - word_size != 0) && (free_words - word_size < CollectedHeap::min_fill_size()))) {
    // Retiring the current chunk
    if (old_top != _max) {
      // Non-zero space; need to insert the filler
      size_t fill_size = free_words;
      CollectedHeap::fill_with_object(old_top, fill_size);
    }
    // Set the current chunk as "full"
    _allocation_region->set_top(_max);

    // Check if we've just used up the last min_region_size'd chunk
    // in the current region, and if so, allocate a new one.
    if (_max != _allocation_region->end()) {
      // Shift to the next chunk
      old_top = _bottom = _max;
      _max = _bottom + HeapRegion::min_region_size_in_words();
    } else {
      if (!alloc_new_region()) {
        return NULL;
      }
      old_top = _allocation_region->bottom();
    }
  }
  assert(pointer_delta(_max, old_top) >= word_size, "enough space left");
  _allocation_region->set_top(old_top + word_size);

  return old_top;
}

void G1ArchiveAllocator::complete_archive(GrowableArray<MemRegion>* ranges,
                                          size_t end_alignment_in_bytes) {
  assert((end_alignment_in_bytes >> LogHeapWordSize) < HeapRegion::min_region_size_in_words(),
         "alignment " SIZE_FORMAT " too large", end_alignment_in_bytes);
  assert(is_aligned(end_alignment_in_bytes, HeapWordSize),
         "alignment " SIZE_FORMAT " is not HeapWord (%u) aligned", end_alignment_in_bytes, HeapWordSize);

  // If we've allocated nothing, simply return.
  if (_allocation_region == NULL) {
    return;
  }

  // If an end alignment was requested, insert filler objects.
  if (end_alignment_in_bytes != 0) {
    HeapWord* currtop = _allocation_region->top();
    HeapWord* newtop = align_up(currtop, end_alignment_in_bytes);
    size_t fill_size = pointer_delta(newtop, currtop);
    if (fill_size != 0) {
      if (fill_size < CollectedHeap::min_fill_size()) {
        // If the required fill is smaller than we can represent,
        // bump up to the next aligned address. We know we won't exceed the current
        // region boundary because the max supported alignment is smaller than the min
        // region size, and because the allocation code never leaves space smaller than
        // the min_fill_size at the top of the current allocation region.
        newtop = align_up(currtop + CollectedHeap::min_fill_size(),
                          end_alignment_in_bytes);
        fill_size = pointer_delta(newtop, currtop);
      }
      HeapWord* fill = archive_mem_allocate(fill_size);
      CollectedHeap::fill_with_objects(fill, fill_size);
    }
  }

  // Loop through the allocated regions, and create MemRegions summarizing
  // the allocated address range, combining contiguous ranges. Add the
  // MemRegions to the GrowableArray provided by the caller.
  int index = _allocated_regions.length() - 1;
  assert(_allocated_regions.at(index) == _allocation_region,
         "expected region %u at end of array, found %u",
         _allocation_region->hrm_index(), _allocated_regions.at(index)->hrm_index());
  HeapWord* base_address = _allocation_region->bottom();
  HeapWord* top = base_address;

  while (index >= 0) {
    HeapRegion* next = _allocated_regions.at(index);
    HeapWord* new_base = next->bottom();
    HeapWord* new_top = next->top();
    if (new_base != top) {
      ranges->append(MemRegion(base_address, pointer_delta(top, base_address)));
      base_address = new_base;
    }
    top = new_top;
    index = index - 1;
  }

  assert(top != base_address, "zero-sized range, address " PTR_FORMAT, p2i(base_address));
  ranges->append(MemRegion(base_address, pointer_delta(top, base_address)));
  _allocated_regions.clear();
  _allocation_region = NULL;
};