// SPDX-License-Identifier: BSD-2-Clause

/* Copyright (C) 2014 - 2020 Intel Corporation. */

#pragma once

#include <hbwmalloc.h>

#include <stddef.h>

#include <new>

/*

 * Header file for the C++ allocator compatible with the C++ standard library allocator concepts.

 * More details in hbwallocator(3) man page.

 * Note: memory heap management is based on hbwmalloc, refer to the hbwmalloc man page for more information.

 *

 * Functionality defined in this header is considered as EXPERIMENTAL API.

 * API standards are described in memkind(3) man page.

 */

namespace hbw

{

    template <class T>

    class allocator

    {

    public:

        /*

         *  Public member types required and defined by the standard library allocator concepts.

         */

        typedef size_t size_type;

        typedef ptrdiff_t difference_type;

        typedef T *pointer;

        typedef const T *const_pointer;

        typedef T &reference;

        typedef const T &const_reference;

        typedef T value_type;

        template <class U>

        struct rebind {

            typedef hbw::allocator<U> other;

        };

        /*

         *  Public member functions required and defined by the standard library allocator concepts.

         */

        allocator() throw() { }

        template <class U>

        allocator(const allocator<U> &) throw() { }

        ~allocator() throw() { }

        pointer address(reference x) const

        {

            return &x;

        }

        const_pointer address(const_reference x) const

        {

            return &x;

        }

        /*

         *  Allocates n*sizeof(T) bytes of high bandwidth memory using hbw_malloc().

         *  Throws std::bad_alloc when cannot allocate memory.

         */

        pointer allocate(size_type n, const void * = 0)

        {

            if (n > this->max_size()) {

                throw std::bad_alloc();

            }

            pointer result = static_cast<pointer>(hbw_malloc(n * sizeof(T)));

            if (!result) {

                throw std::bad_alloc();

            }

            return result;

        }

        /*

         *  Deallocates memory associated with pointer returned by allocate() using hbw_free().

         */

        void deallocate(pointer p, size_type n)

        {

            hbw_free(static_cast<void *>(p));

        }

        size_type max_size() const throw()

        {

            return size_t(-1) / sizeof(T);

        }

        void construct(pointer p, const_reference val)

        {

            ::new(p) value_type(val);

        }

        void destroy(pointer p)

        {

            p->~T();

        }

    };

    template <class T, class U>

    bool operator==(const allocator<T> &, const allocator<U> &)

    {

        return true;

    }

    template <class T, class U>

    bool operator!=(const allocator<T> &, const allocator<U> &)

    {

        return false;

    }

}