memory_resource

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/*
 * This file is part of the µOS++ distribution.
 *   (https://github.com/micro-os-plus)
 * Copyright (c) 2016-2023 Liviu Ionescu. All rights reserved.
 *
 * Permission to use, copy, modify, and/or distribute this software
 * for any purpose is hereby granted, under the terms of the MIT license.
 *
 * If a copy of the license was not distributed with this file, it can
 * be obtained from https://opensource.org/licenses/mit/.
 */
 
#ifndef CMSIS_PLUS_ISO_MEMORY_
#define CMSIS_PLUS_ISO_MEMORY_
 
#include <cmsis-plus/rtos/os-memory.h>
 
#include <cstddef>
#include <cerrno>
#include <cassert>
#include <limits>
#include <memory>
 
// ----------------------------------------------------------------------------
 
#pragma GCC diagnostic push
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wc++98-compat"
#endif
 
// ----------------------------------------------------------------------------
 
namespace os
{
  namespace estd
  {
 
    // ========================================================================
 
    // in os-memory.h
    // [[noreturn]] void
    // __throw_bad_alloc (void);
 
    namespace pmr
    {
      // ======================================================================
 
      using memory_resource = rtos::memory::memory_resource;
 
      template<typename T>
        class polymorphic_allocator;
 
      template<typename T1, typename T2>
        bool
        operator== (const polymorphic_allocator<T1>& a,
                    const polymorphic_allocator<T2>& b) noexcept;
 
      template<typename T1, typename T2>
        bool
        operator!= (const polymorphic_allocator<T1>& a,
                    const polymorphic_allocator<T2>& b) noexcept;
 
      memory_resource*
      new_delete_resource (void) noexcept;
 
      memory_resource*
      null_memory_resource (void) noexcept;
 
      memory_resource*
      set_default_resource (memory_resource* res) noexcept;
 
      memory_resource*
      get_default_resource (void) noexcept;
 
      extern memory_resource* default_resource;
 
      // ======================================================================
 
      template<typename T>
        class polymorphic_allocator
        {
        public:
 
          typedef T value_type;
 
          polymorphic_allocator () noexcept;
 
          polymorphic_allocator (memory_resource* r) noexcept;
 
          polymorphic_allocator (polymorphic_allocator const & a) = default;
 
          template<typename U>
            polymorphic_allocator (polymorphic_allocator<U> const & other)
                noexcept;
 
          polymorphic_allocator&
          operator= (polymorphic_allocator const & a) = default;
 
          value_type*
          allocate (std::size_t n);
 
          void
          deallocate (value_type* p, std::size_t n) noexcept;
 
          std::size_t
          max_size (void) const noexcept;
 
          polymorphic_allocator
          select_on_container_copy_construction (void) const noexcept;
 
          memory_resource*
          resource (void) const noexcept;
 
        private:
 
          memory_resource* res_;
        };
 
    // ------------------------------------------------------------------------
    } /* namespace pmr */
  } /* namespace estd */
} /* namespace os */
 
// ===== Inline & template implementations ====================================
 
namespace os
{
  namespace estd
  {
    namespace pmr
    {
 
      // ======================================================================
 
      inline memory_resource*
      get_default_resource (void) noexcept
      {
        rtos::memory::init_once_default_resource ();
        return default_resource;
      }
 
      // ======================================================================
 
      template<typename T>
        polymorphic_allocator<T>::polymorphic_allocator () noexcept :
        res_(get_default_resource())
          {
          }
 
      template<typename T>
        inline
        polymorphic_allocator<T>::polymorphic_allocator (memory_resource* r) noexcept :
        res_(r)
          {
          }
 
      template<typename T>
        template<typename U>
          inline
          polymorphic_allocator<T>::polymorphic_allocator (
              polymorphic_allocator<U> const & other) noexcept :
          res_(other.resource())
            {
            }
 
      template<typename T>
        inline typename polymorphic_allocator<T>::value_type*
        polymorphic_allocator<T>::allocate (std::size_t n)
        {
          if (n > max_size ())
            {
              estd::__throw_system_error (
                  EINVAL, "polymorphic_allocator<T>::allocate(std::size_t n)"
                  " 'n' exceeds maximum supported size");
            }
 
          return static_cast<value_type*> (res_->allocate (
              n * sizeof(value_type), alignof(value_type)));
        }
 
      template<typename T>
        inline void
        polymorphic_allocator<T>::deallocate (value_type* p, std::size_t n) noexcept
        {
          assert(n <= max_size ());
          res_->deallocate (p, n * sizeof(value_type), alignof(value_type));
        }
 
      template<typename T>
        inline std::size_t
        polymorphic_allocator<T>::max_size (void) const noexcept
        {
          return std::numeric_limits<std::size_t>::max () / sizeof(value_type);
        }
 
      template<typename T>
        inline polymorphic_allocator<T>
        polymorphic_allocator<T>::select_on_container_copy_construction (
            void) const noexcept
        {
          return polymorphic_allocator ();
        }
 
      template<typename T>
        inline memory_resource*
        polymorphic_allocator<T>::resource (void) const noexcept
        {
          return res_;
        }
 
      // ======================================================================
 
      template<typename T, typename U>
        inline bool
        operator== (polymorphic_allocator<T> const & lhs,
                    polymorphic_allocator<U> const & rhs) noexcept
        {
          return *lhs.resource () == *rhs.resource ();
        }
 
      template<typename T, typename U>
        inline bool
        operator!= (polymorphic_allocator<T> const & lhs,
                    polymorphic_allocator<U> const & rhs) noexcept
        {
          return !(lhs == rhs);
        }
 
    // ------------------------------------------------------------------------
    } /* namespace pmr */
  } /* namespace estd */
} /* namespace os */
 
#pragma GCC diagnostic pop
 
// ----------------------------------------------------------------------------
 
#endif /* CMSIS_PLUS_ISO_MEMORY_ */