/*

 * Copyright (c) 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.

 *

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#ifndef SHARE_VM_GC_G1_NUMA_HPP

#define SHARE_VM_GC_G1_NUMA_HPP

#include "memory/allocation.hpp"

#include "runtime/os.hpp"

class G1NUMA: public CHeapObj<mtGC> {

  // Mapping of available node ids to  0-based index which can be used for

  // fast resource management. I.e. for every node id provides a unique value in

  // the range from [0, {# of nodes-1}].

  // For invalid node id, return UnknownNodeIndex.

  uint* _node_id_to_index_map;

  // Length of _num_active_node_ids_id to index map.

  int _len_node_id_to_index_map;

  // Current active node ids.

  int* _node_ids;

  // Total number of node ids.

  uint _num_active_node_ids;

  // HeapRegion size

  size_t _region_size;

  // Necessary when touching memory.

  size_t _page_size;

  size_t region_size() const;

  size_t page_size() const;

  // Returns node index of the given node id.

  // Precondition: node_id is an active node id.

  inline uint index_of_node_id(int node_id) const;

  // Creates node id and node index mapping table of _node_id_to_index_map.

  void init_node_id_to_index_map(const int* node_ids, uint num_node_ids);

  static G1NUMA* _inst;

  G1NUMA();

  void initialize(bool use_numa);

  void initialize_without_numa();

public:

  static const uint UnknownNodeIndex = UINT_MAX;

  static const uint AnyNodeIndex = UnknownNodeIndex - 1;

  static G1NUMA* numa() { return _inst; }

  static G1NUMA* create();

  ~G1NUMA();

  // Sets heap region size and page size after those values

  // are determined at G1CollectedHeap::initialize().

  void set_region_info(size_t region_size, size_t page_size);

  // Returns active memory node count.

  uint num_active_nodes() const;

  bool is_enabled() const;

  int numa_id(int index) const;

  // Returns memory node ids

  const int* node_ids() const;

  // Returns node index of current calling thread.

  uint index_of_current_thread() const;

  // Returns the preferred index for the given HeapRegion index.

  // This assumes that HeapRegions are evenly spit, so we can decide preferred index

  // with the given HeapRegion index.

  // Result is less than num_active_nodes().

  uint preferred_node_index_for_index(uint region_index) const;

  // Retrieves node index of the given address.

  // Result is less than num_active_nodes() or is UnknownNodeIndex.

  // Precondition: address is in reserved range for heap.

  uint index_of_address(HeapWord* address) const;

  // If AlwaysPreTouch is enabled, return actual node index via system call.

  // If disabled, return preferred node index of the given heap region.

  uint index_for_region(HeapRegion* hr) const;

  // Requests the given memory area to be located at the given node index.

  void request_memory_on_node(void* aligned_address, size_t size_in_bytes, uint region_index);

  // Returns maximum search depth which is used to limit heap region search iterations.

  // The number of active nodes, page size and heap region size are considered.

  uint max_search_depth() const;

};

#endif // SHARE_VM_GC_G1_NUMA_HPP