view src/hotspot/share/memory/metaspace/virtualSpaceList.hpp @ 51151:1ddf9a99e4ad

Added tag jdk-11+28 for changeset 76072a077ee1
author jwilhelm
date Wed, 22 Aug 2018 21:50:12 +0200
parents 49c3e91c424f
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 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
 * 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 if you need additional information or have any
 * questions.


#include "memory/allocation.hpp"
#include "memory/metaspace/virtualSpaceNode.hpp"
#include "utilities/globalDefinitions.hpp"

namespace metaspace {

class Metachunk;
class ChunkManager;

// List of VirtualSpaces for metadata allocation.
class VirtualSpaceList : public CHeapObj<mtClass> {
  friend class VirtualSpaceNode;

  enum VirtualSpaceSizes {
    VirtualSpaceSize = 256 * K

  // Head of the list
  VirtualSpaceNode* _virtual_space_list;
  // virtual space currently being used for allocations
  VirtualSpaceNode* _current_virtual_space;

  // Is this VirtualSpaceList used for the compressed class space
  bool _is_class;

  // Sum of reserved and committed memory in the virtual spaces
  size_t _reserved_words;
  size_t _committed_words;

  // Number of virtual spaces
  size_t _virtual_space_count;


  VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; }

  void set_virtual_space_list(VirtualSpaceNode* v) {
    _virtual_space_list = v;
  void set_current_virtual_space(VirtualSpaceNode* v) {
    _current_virtual_space = v;

  void link_vs(VirtualSpaceNode* new_entry);

  // Get another virtual space and add it to the list.  This
  // is typically prompted by a failed attempt to allocate a chunk
  // and is typically followed by the allocation of a chunk.
  bool create_new_virtual_space(size_t vs_word_size);

  // Chunk up the unused committed space in the current
  // virtual space and add the chunks to the free list.
  void retire_current_virtual_space();

  VirtualSpaceList(size_t word_size);
  VirtualSpaceList(ReservedSpace rs);

  size_t free_bytes();

  Metachunk* get_new_chunk(size_t chunk_word_size,
                           size_t suggested_commit_granularity);

  bool expand_node_by(VirtualSpaceNode* node,
                      size_t min_words,
                      size_t preferred_words);

  bool expand_by(size_t min_words,
                 size_t preferred_words);

  VirtualSpaceNode* current_virtual_space() {
    return _current_virtual_space;

  bool is_class() const { return _is_class; }

  bool initialization_succeeded() { return _virtual_space_list != NULL; }

  size_t reserved_words()  { return _reserved_words; }
  size_t reserved_bytes()  { return reserved_words() * BytesPerWord; }
  size_t committed_words() { return _committed_words; }
  size_t committed_bytes() { return committed_words() * BytesPerWord; }

  void inc_reserved_words(size_t v);
  void dec_reserved_words(size_t v);
  void inc_committed_words(size_t v);
  void dec_committed_words(size_t v);
  void inc_virtual_space_count();
  void dec_virtual_space_count();

  bool contains(const void* ptr);

  // Unlink empty VirtualSpaceNodes and free it.
  void purge(ChunkManager* chunk_manager);

  void print_on(outputStream* st) const                 { print_on(st, K); }
  void print_on(outputStream* st, size_t scale) const;
  void print_map(outputStream* st) const;

  class VirtualSpaceListIterator : public StackObj {
    VirtualSpaceNode* _virtual_spaces;
    VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) :
      _virtual_spaces(virtual_spaces) {}

    bool repeat() {
      return _virtual_spaces != NULL;

    VirtualSpaceNode* get_next() {
      VirtualSpaceNode* result = _virtual_spaces;
      if (_virtual_spaces != NULL) {
        _virtual_spaces = _virtual_spaces->next();
      return result;

} // namespace metaspace