/*
 * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2020 SAP SE. 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
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#ifndef SHARE_MEMORY_METASPACE_CONSTANTS_HPP
#define SHARE_MEMORY_METASPACE_CONSTANTS_HPP

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

namespace metaspace {

class Settings : public AllStatic {

  // Granularity, in bytes, metaspace is committed with.
  static size_t _commit_granule_bytes;

  // Granularity, in words, metaspace is committed with.
  static size_t _commit_granule_words;

  // The default size of a non-class VirtualSpaceNode (unless created differently).
  // Must be a multiple of the root chunk size.
  static const size_t _virtual_space_node_default_word_size = chunklevel::MAX_CHUNK_WORD_SIZE * 2; // lets go with 8mb virt size. Seems a good compromise betw. virt and mapping fragmentation.

  // Alignment of the base address of a virtual space node
  static const size_t _virtual_space_node_reserve_alignment_words = chunklevel::MAX_CHUNK_WORD_SIZE;

  // When allocating from a chunk, if the remaining area in the chunk is too small to hold
  // the requested size, we attempt to double the chunk size in place...
  static const bool _enlarge_chunks_in_place = true;

  // .. but we do only do this for chunks below a given size to prevent unnecessary memory blowup.
  static const size_t _enlarge_chunks_in_place_max_word_size = 256 * K;

  // Whether or not chunks handed out to an arena start out fully committed;
  // if true, this deactivates committing-on-demand (irregardless of whether
  // we uncommit free chunks).
  static bool _new_chunks_are_fully_committed;

  // If true, chunks equal or larger than a commit granule are uncommitted
  // after being returned to the freelist.
  static bool _uncommit_free_chunks;

  // If true, metablock allocations are guarded and periodically checked.
  DEBUG_ONLY(static bool _use_allocation_guard;)

  // If true, we handle deallocated blocks (default).
  DEBUG_ONLY(static bool _handle_deallocations;)

public:

  static size_t commit_granule_bytes()                        { return _commit_granule_bytes; }
  static size_t commit_granule_words()                        { return _commit_granule_words; }
  static bool new_chunks_are_fully_committed()                { return _new_chunks_are_fully_committed; }
  static size_t virtual_space_node_default_word_size()        { return _virtual_space_node_default_word_size; }
  static size_t virtual_space_node_reserve_alignment_words()  { return _virtual_space_node_reserve_alignment_words; }
  static bool enlarge_chunks_in_place()                       { return _enlarge_chunks_in_place; }
  static size_t enlarge_chunks_in_place_max_word_size()       { return _enlarge_chunks_in_place_max_word_size; }
  static bool uncommit_free_chunks()                          { return _uncommit_free_chunks; }

  static bool use_allocation_guard()                          { return DEBUG_ONLY(_use_allocation_guard) NOT_DEBUG(false); }
  static bool handle_deallocations()                          { return DEBUG_ONLY(_handle_deallocations) NOT_DEBUG(true); }

  static void ergo_initialize();

  static void print_on(outputStream* st);

};

} // namespace metaspace

#endif // SHARE_MEMORY_METASPACE_BLOCKFREELIST_HPP