src/hotspot/share/gc/z/zVirtualMemoryManager.hpp

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
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 *
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 * 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).
 *
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 * 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_GC_Z_ZVIRTUALMEMORYMANAGER_HPP
#define SHARE_GC_Z_ZVIRTUALMEMORYMANAGER_HPP

#include "gc/z/zAddress.hpp"
#include "gc/z/zArray.hpp"
#include "gc/z/zRangeRegistry.hpp"
#include "gc/z/zValue.hpp"
#include "gc/z/zVirtualMemory.hpp"

using ZVirtualMemoryRegistry = ZRangeRegistry<ZVirtualMemory>;

class ZVirtualMemoryReserver {
  friend class ZMapperTest;
  friend class ZVirtualMemoryManagerTest;

private:

  ZVirtualMemoryRegistry _registry;
  const size_t           _reserved;

  static size_t calculate_min_range(size_t size);

  // Platform specific implementation
  void pd_register_callbacks(ZVirtualMemoryRegistry* registry);
  bool pd_reserve(zaddress_unsafe addr, size_t size);
  void pd_unreserve(zaddress_unsafe addr, size_t size);

  bool reserve_contiguous(zoffset start, size_t size);
  bool reserve_contiguous(size_t size);
  size_t reserve_discontiguous(zoffset start, size_t size, size_t min_range);
  size_t reserve_discontiguous(size_t size);

  size_t reserve(size_t size);
  void unreserve(const ZVirtualMemory& vmem);

  DEBUG_ONLY(size_t force_reserve_discontiguous(size_t size);)

public:
  ZVirtualMemoryReserver(size_t size);

  void initialize_partition_registry(ZVirtualMemoryRegistry* partition_registry, size_t size);

  void unreserve_all();

  bool is_empty() const;
  bool is_contiguous() const;

  size_t reserved() const;

  zoffset_end highest_available_address_end() const;
};

class ZVirtualMemoryManager {
private:
  ZPerNUMA<ZVirtualMemoryRegistry> _partition_registries;
  ZVirtualMemoryRegistry           _multi_partition_registry;
  bool                             _is_multi_partition_enabled;
  bool                             _initialized;

  ZVirtualMemoryRegistry& registry(uint32_t partition_id);
  const ZVirtualMemoryRegistry& registry(uint32_t partition_id) const;

public:
  ZVirtualMemoryManager(size_t max_capacity);

  void initialize_partitions(ZVirtualMemoryReserver* reserver, size_t size_for_partitions);

  bool is_initialized() const;
  bool is_multi_partition_enabled() const;
  bool is_in_multi_partition(const ZVirtualMemory& vmem) const;

  uint32_t lookup_partition_id(const ZVirtualMemory& vmem) const;
  zoffset lowest_available_address(uint32_t partition_id) const;

  void insert(const ZVirtualMemory& vmem, uint32_t partition_id);
  void insert_multi_partition(const ZVirtualMemory& vmem);

  size_t remove_from_low_many_at_most(size_t size, uint32_t partition_id, ZArray<ZVirtualMemory>* vmems_out);
  ZVirtualMemory remove_from_low(size_t size, uint32_t partition_id);
  ZVirtualMemory remove_from_low_multi_partition(size_t size);

  void insert_and_remove_from_low_many(const ZVirtualMemory& vmem, uint32_t partition_id, ZArray<ZVirtualMemory>* vmems_out);
  ZVirtualMemory insert_and_remove_from_low_exact_or_many(size_t size, uint32_t partition_id, ZArray<ZVirtualMemory>* vmems_in_out);
};

#endif // SHARE_GC_Z_ZVIRTUALMEMORYMANAGER_HPP