/*
 * Copyright (c) 2015, 2025, 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.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

#ifndef SHARE_GC_Z_ZOBJECTALLOCATOR_HPP
#define SHARE_GC_Z_ZOBJECTALLOCATOR_HPP

#include "gc/z/zAddress.hpp"
#include "gc/z/zAllocationFlags.hpp"
#include "gc/z/zDeferredConstructed.hpp"
#include "gc/z/zLock.hpp"
#include "gc/z/zPage.hpp"
#include "gc/z/zPageAge.hpp"
#include "gc/z/zValue.hpp"

class ZObjectAllocator {
private:
  class PerAge {
  private:
    const ZPageAge     _age;
    const bool         _use_per_cpu_shared_small_pages;
    ZPerCPU<ZPage*>    _shared_small_page;
    ZContended<ZPage*> _shared_medium_page;
    ZLock              _medium_page_alloc_lock;

  public:
    PerAge(ZPageAge age);

    ZPage** shared_small_page_addr();
    ZPage* const* shared_small_page_addr() const;

    ZPage* alloc_page(ZPageType type, size_t size, ZAllocationFlags flags);
    void undo_alloc_page(ZPage* page);

    // Allocate an object in a shared page. Allocate and
    // atomically install a new page if necessary.
    zaddress alloc_object_in_shared_page(ZPage** shared_page,
                                         ZPageType page_type,
                                         size_t page_size,
                                         size_t size,
                                         ZAllocationFlags flags);

    zaddress alloc_object_in_medium_page(size_t size,
                                         ZAllocationFlags flags);

    zaddress alloc_large_object(size_t size, ZAllocationFlags flags);
    zaddress alloc_medium_object(size_t size, ZAllocationFlags flags);
    zaddress alloc_small_object(size_t size, ZAllocationFlags flags);
    zaddress alloc_object(size_t size, ZAllocationFlags flags);

    void retire_pages();
  };

  ZDeferredConstructed<PerAge> _allocators[ZPageAgeCount];

  PerAge* allocator(ZPageAge age);
  const PerAge* allocator(ZPageAge age) const;

public:
  ZObjectAllocator();

  void retire_pages(ZPageAgeRange range);

  size_t fast_available(ZPageAge age) const;

  // Mutator allocation
  zaddress alloc(size_t size);

  // Mutator relocation
  zaddress alloc_for_relocation(size_t size, ZPageAge age);
};

#endif // SHARE_GC_Z_ZOBJECTALLOCATOR_HPP