mirror of git://gcc.gnu.org/git/gcc.git
390 lines
12 KiB
C++
390 lines
12 KiB
C++
// <experimental/memory_resource> -*- C++ -*-
|
|
|
|
// Copyright (C) 2015-2018 Free Software Foundation, Inc.
|
|
//
|
|
// This file is part of the GNU ISO C++ Library. This library is free
|
|
// software; you can redistribute it and/or modify it under the
|
|
// terms of the GNU General Public License as published by the
|
|
// Free Software Foundation; either version 3, or (at your option)
|
|
// any later version.
|
|
|
|
// This library 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 for more details.
|
|
|
|
// Under Section 7 of GPL version 3, you are granted additional
|
|
// permissions described in the GCC Runtime Library Exception, version
|
|
// 3.1, as published by the Free Software Foundation.
|
|
|
|
// You should have received a copy of the GNU General Public License and
|
|
// a copy of the GCC Runtime Library Exception along with this program;
|
|
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
|
// <http://www.gnu.org/licenses/>.
|
|
|
|
/** @file experimental/memory_resource
|
|
* This is a TS C++ Library header.
|
|
*/
|
|
|
|
#ifndef _GLIBCXX_EXPERIMENTAL_MEMORY_RESOURCE
|
|
#define _GLIBCXX_EXPERIMENTAL_MEMORY_RESOURCE 1
|
|
|
|
#include <memory>
|
|
#include <new>
|
|
#include <atomic>
|
|
#include <cstddef>
|
|
#include <bits/alloc_traits.h>
|
|
#include <experimental/bits/lfts_config.h>
|
|
|
|
namespace std {
|
|
_GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|
|
|
namespace experimental {
|
|
inline namespace fundamentals_v2 {
|
|
namespace pmr {
|
|
#define __cpp_lib_experimental_memory_resources 201402L
|
|
|
|
class memory_resource;
|
|
|
|
template <typename _Tp>
|
|
class polymorphic_allocator;
|
|
|
|
template <typename _Alloc>
|
|
class __resource_adaptor_imp;
|
|
|
|
template <typename _Alloc>
|
|
using resource_adaptor = __resource_adaptor_imp<
|
|
typename allocator_traits<_Alloc>::template rebind_alloc<char>>;
|
|
|
|
template <typename _Tp>
|
|
struct __uses_allocator_construction_helper;
|
|
|
|
// Global memory resources
|
|
memory_resource* new_delete_resource() noexcept;
|
|
memory_resource* null_memory_resource() noexcept;
|
|
|
|
// The default memory resource
|
|
memory_resource* get_default_resource() noexcept;
|
|
memory_resource* set_default_resource(memory_resource* __r) noexcept;
|
|
|
|
// Standard memory resources
|
|
|
|
// 8.5 Class memory_resource
|
|
class memory_resource
|
|
{
|
|
protected:
|
|
static constexpr size_t _S_max_align = alignof(max_align_t);
|
|
|
|
public:
|
|
virtual ~memory_resource() { }
|
|
|
|
void*
|
|
allocate(size_t __bytes, size_t __alignment = _S_max_align)
|
|
{ return do_allocate(__bytes, __alignment); }
|
|
|
|
void
|
|
deallocate(void* __p, size_t __bytes, size_t __alignment = _S_max_align)
|
|
{ return do_deallocate(__p, __bytes, __alignment); }
|
|
|
|
bool
|
|
is_equal(const memory_resource& __other) const noexcept
|
|
{ return do_is_equal(__other); }
|
|
|
|
protected:
|
|
virtual void*
|
|
do_allocate(size_t __bytes, size_t __alignment) = 0;
|
|
|
|
virtual void
|
|
do_deallocate(void* __p, size_t __bytes, size_t __alignment) = 0;
|
|
|
|
virtual bool
|
|
do_is_equal(const memory_resource& __other) const noexcept = 0;
|
|
};
|
|
|
|
inline bool
|
|
operator==(const memory_resource& __a,
|
|
const memory_resource& __b) noexcept
|
|
{ return &__a == &__b || __a.is_equal(__b); }
|
|
|
|
inline bool
|
|
operator!=(const memory_resource& __a,
|
|
const memory_resource& __b) noexcept
|
|
{ return !(__a == __b); }
|
|
|
|
|
|
// 8.6 Class template polymorphic_allocator
|
|
template <class _Tp>
|
|
class polymorphic_allocator
|
|
{
|
|
using __uses_alloc1_ = __uses_alloc1<memory_resource*>;
|
|
using __uses_alloc2_ = __uses_alloc2<memory_resource*>;
|
|
|
|
template<typename _Tp1, typename... _Args>
|
|
void
|
|
_M_construct(__uses_alloc0, _Tp1* __p, _Args&&... __args)
|
|
{ ::new(__p) _Tp1(std::forward<_Args>(__args)...); }
|
|
|
|
template<typename _Tp1, typename... _Args>
|
|
void
|
|
_M_construct(__uses_alloc1_, _Tp1* __p, _Args&&... __args)
|
|
{ ::new(__p) _Tp1(allocator_arg, this->resource(),
|
|
std::forward<_Args>(__args)...); }
|
|
|
|
template<typename _Tp1, typename... _Args>
|
|
void
|
|
_M_construct(__uses_alloc2_, _Tp1* __p, _Args&&... __args)
|
|
{ ::new(__p) _Tp1(std::forward<_Args>(__args)...,
|
|
this->resource()); }
|
|
|
|
public:
|
|
using value_type = _Tp;
|
|
|
|
polymorphic_allocator() noexcept
|
|
: _M_resource(get_default_resource())
|
|
{ }
|
|
|
|
polymorphic_allocator(memory_resource* __r)
|
|
: _M_resource(__r)
|
|
{ _GLIBCXX_DEBUG_ASSERT(__r); }
|
|
|
|
polymorphic_allocator(const polymorphic_allocator& __other) = default;
|
|
|
|
template <typename _Up>
|
|
polymorphic_allocator(const polymorphic_allocator<_Up>&
|
|
__other) noexcept
|
|
: _M_resource(__other.resource())
|
|
{ }
|
|
|
|
polymorphic_allocator&
|
|
operator=(const polymorphic_allocator& __rhs) = default;
|
|
|
|
_Tp* allocate(size_t __n)
|
|
{ return static_cast<_Tp*>(_M_resource->allocate(__n * sizeof(_Tp),
|
|
alignof(_Tp))); }
|
|
|
|
void deallocate(_Tp* __p, size_t __n)
|
|
{ _M_resource->deallocate(__p, __n * sizeof(_Tp), alignof(_Tp)); }
|
|
|
|
template <typename _Tp1, typename... _Args> //used here
|
|
void construct(_Tp1* __p, _Args&&... __args)
|
|
{
|
|
memory_resource* const __resource = this->resource();
|
|
auto __use_tag
|
|
= __use_alloc<_Tp1, memory_resource*, _Args...>(__resource);
|
|
_M_construct(__use_tag, __p, std::forward<_Args>(__args)...);
|
|
}
|
|
|
|
// Specializations for pair using piecewise construction
|
|
template <typename _Tp1, typename _Tp2,
|
|
typename... _Args1, typename... _Args2>
|
|
void construct(pair<_Tp1, _Tp2>* __p, piecewise_construct_t,
|
|
tuple<_Args1...> __x,
|
|
tuple<_Args2...> __y)
|
|
{
|
|
memory_resource* const __resource = this->resource();
|
|
auto __x_use_tag =
|
|
__use_alloc<_Tp1, memory_resource*, _Args1...>(__resource);
|
|
auto __y_use_tag =
|
|
__use_alloc<_Tp2, memory_resource*, _Args2...>(__resource);
|
|
|
|
::new(__p) std::pair<_Tp1, _Tp2>(piecewise_construct,
|
|
_M_construct_p(__x_use_tag, __x),
|
|
_M_construct_p(__y_use_tag, __y));
|
|
}
|
|
|
|
template <typename _Tp1, typename _Tp2>
|
|
void construct(pair<_Tp1,_Tp2>* __p)
|
|
{ this->construct(__p, piecewise_construct, tuple<>(), tuple<>()); }
|
|
|
|
template <typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
|
|
void construct(pair<_Tp1,_Tp2>* __p, _Up&& __x, _Vp&& __y)
|
|
{ this->construct(__p, piecewise_construct,
|
|
forward_as_tuple(std::forward<_Up>(__x)),
|
|
forward_as_tuple(std::forward<_Vp>(__y))); }
|
|
|
|
template <typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
|
|
void construct(pair<_Tp1,_Tp2>* __p, const std::pair<_Up, _Vp>& __pr)
|
|
{ this->construct(__p, piecewise_construct, forward_as_tuple(__pr.first),
|
|
forward_as_tuple(__pr.second)); }
|
|
|
|
template <typename _Tp1, typename _Tp2, typename _Up, typename _Vp>
|
|
void construct(pair<_Tp1,_Tp2>* __p, pair<_Up, _Vp>&& __pr)
|
|
{ this->construct(__p, piecewise_construct,
|
|
forward_as_tuple(std::forward<_Up>(__pr.first)),
|
|
forward_as_tuple(std::forward<_Vp>(__pr.second))); }
|
|
|
|
template <typename _Up>
|
|
void destroy(_Up* __p)
|
|
{ __p->~_Up(); }
|
|
|
|
// Return a default-constructed allocator (no allocator propagation)
|
|
polymorphic_allocator select_on_container_copy_construction() const
|
|
{ return polymorphic_allocator(); }
|
|
|
|
memory_resource* resource() const
|
|
{ return _M_resource; }
|
|
|
|
private:
|
|
template<typename _Tuple>
|
|
_Tuple&&
|
|
_M_construct_p(__uses_alloc0, _Tuple& __t)
|
|
{ return std::move(__t); }
|
|
|
|
template<typename... _Args>
|
|
decltype(auto)
|
|
_M_construct_p(__uses_alloc1_ __ua, tuple<_Args...>& __t)
|
|
{ return tuple_cat(make_tuple(allocator_arg, *(__ua._M_a)),
|
|
std::move(__t)); }
|
|
|
|
template<typename... _Args>
|
|
decltype(auto)
|
|
_M_construct_p(__uses_alloc2_ __ua, tuple<_Args...>& __t)
|
|
{ return tuple_cat(std::move(__t), make_tuple(*(__ua._M_a))); }
|
|
|
|
memory_resource* _M_resource;
|
|
};
|
|
|
|
template <class _Tp1, class _Tp2>
|
|
bool operator==(const polymorphic_allocator<_Tp1>& __a,
|
|
const polymorphic_allocator<_Tp2>& __b) noexcept
|
|
{ return *__a.resource() == *__b.resource(); }
|
|
|
|
template <class _Tp1, class _Tp2>
|
|
bool operator!=(const polymorphic_allocator<_Tp1>& __a,
|
|
const polymorphic_allocator<_Tp2>& __b) noexcept
|
|
{ return !(__a == __b); }
|
|
|
|
// 8.7.1 __resource_adaptor_imp
|
|
template <typename _Alloc>
|
|
class __resource_adaptor_imp : public memory_resource
|
|
{
|
|
public:
|
|
using allocator_type = _Alloc;
|
|
|
|
__resource_adaptor_imp() = default;
|
|
__resource_adaptor_imp(const __resource_adaptor_imp&) = default;
|
|
__resource_adaptor_imp(__resource_adaptor_imp&&) = default;
|
|
|
|
explicit __resource_adaptor_imp(const _Alloc& __a2)
|
|
: _M_alloc(__a2)
|
|
{ }
|
|
|
|
explicit __resource_adaptor_imp(_Alloc&& __a2)
|
|
: _M_alloc(std::move(__a2))
|
|
{ }
|
|
|
|
__resource_adaptor_imp&
|
|
operator=(const __resource_adaptor_imp&) = default;
|
|
|
|
allocator_type get_allocator() const { return _M_alloc; }
|
|
|
|
protected:
|
|
virtual void*
|
|
do_allocate(size_t __bytes, size_t __alignment)
|
|
{
|
|
using _Aligned_alloc = std::__alloc_rebind<_Alloc, char>;
|
|
size_t __new_size = _S_aligned_size(__bytes,
|
|
_S_supported(__alignment) ?
|
|
__alignment : _S_max_align);
|
|
return _Aligned_alloc(_M_alloc).allocate(__new_size);
|
|
}
|
|
|
|
virtual void
|
|
do_deallocate(void* __p, size_t __bytes, size_t __alignment)
|
|
{
|
|
using _Aligned_alloc = std::__alloc_rebind<_Alloc, char>;
|
|
size_t __new_size = _S_aligned_size(__bytes,
|
|
_S_supported(__alignment) ?
|
|
__alignment : _S_max_align);
|
|
using _Ptr = typename allocator_traits<_Aligned_alloc>::pointer;
|
|
_Aligned_alloc(_M_alloc).deallocate(static_cast<_Ptr>(__p),
|
|
__new_size);
|
|
}
|
|
|
|
virtual bool
|
|
do_is_equal(const memory_resource& __other) const noexcept
|
|
{
|
|
auto __p = dynamic_cast<const __resource_adaptor_imp*>(&__other);
|
|
return __p ? (_M_alloc == __p->_M_alloc) : false;
|
|
}
|
|
|
|
private:
|
|
// Calculate Aligned Size
|
|
// Returns a size that is larger than or equal to __size and divisible
|
|
// by __alignment, where __alignment is required to be the power of 2.
|
|
static size_t
|
|
_S_aligned_size(size_t __size, size_t __alignment)
|
|
{ return ((__size - 1)|(__alignment - 1)) + 1; }
|
|
|
|
// Determine whether alignment meets one of those preconditions:
|
|
// 1. Equals to Zero
|
|
// 2. Is power of two
|
|
static bool
|
|
_S_supported (size_t __x)
|
|
{ return ((__x != 0) && !(__x & (__x - 1))); }
|
|
|
|
_Alloc _M_alloc;
|
|
};
|
|
|
|
// Global memory resources
|
|
inline std::atomic<memory_resource*>&
|
|
__get_default_resource()
|
|
{
|
|
static atomic<memory_resource*> _S_default_resource(new_delete_resource());
|
|
return _S_default_resource;
|
|
}
|
|
|
|
inline memory_resource*
|
|
new_delete_resource() noexcept
|
|
{
|
|
static resource_adaptor<std::allocator<char>> __r;
|
|
return static_cast<memory_resource*>(&__r);
|
|
}
|
|
|
|
template <typename _Alloc>
|
|
class __null_memory_resource : private memory_resource
|
|
{
|
|
protected:
|
|
void*
|
|
do_allocate(size_t, size_t)
|
|
{ std::__throw_bad_alloc(); }
|
|
|
|
void
|
|
do_deallocate(void*, size_t, size_t) noexcept
|
|
{ }
|
|
|
|
bool
|
|
do_is_equal(const memory_resource& __other) const noexcept
|
|
{ return this == &__other; }
|
|
|
|
friend memory_resource* null_memory_resource() noexcept;
|
|
};
|
|
|
|
inline memory_resource*
|
|
null_memory_resource() noexcept
|
|
{
|
|
static __null_memory_resource<void> __r;
|
|
return static_cast<memory_resource*>(&__r);
|
|
}
|
|
|
|
// The default memory resource
|
|
inline memory_resource*
|
|
get_default_resource() noexcept
|
|
{ return __get_default_resource().load(); }
|
|
|
|
inline memory_resource*
|
|
set_default_resource(memory_resource* __r) noexcept
|
|
{
|
|
if (__r == nullptr)
|
|
__r = new_delete_resource();
|
|
return __get_default_resource().exchange(__r);
|
|
}
|
|
} // namespace pmr
|
|
} // namespace fundamentals_v2
|
|
} // namespace experimental
|
|
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace std
|
|
|
|
#endif
|