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libcxx/include/experimental/memory_resource

427 lines
13 KiB
C++

// -*- C++ -*-
//===------------------------ memory_resource -----------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP_EXPERIMENTAL_MEMORY_RESOURCE
#define _LIBCPP_EXPERIMENTAL_MEMORY_RESOURCE
/**
experimental/memory_resource synopsis
// C++1y
namespace std {
namespace experimental {
inline namespace fundamentals_v1 {
namespace pmr {
class memory_resource;
bool operator==(const memory_resource& a,
const memory_resource& b) noexcept;
bool operator!=(const memory_resource& a,
const memory_resource& b) noexcept;
template <class Tp> class polymorphic_allocator;
template <class T1, class T2>
bool operator==(const polymorphic_allocator<T1>& a,
const polymorphic_allocator<T2>& b) noexcept;
template <class T1, class T2>
bool operator!=(const polymorphic_allocator<T1>& a,
const polymorphic_allocator<T2>& b) noexcept;
// The name resource_adaptor_imp is for exposition only.
template <class Allocator> class resource_adaptor_imp;
template <class Allocator>
using resource_adaptor = resource_adaptor_imp<
allocator_traits<Allocator>::rebind_alloc<char>>;
// Global memory resources
memory_resource* new_delete_resource() noexcept;
memory_resource* null_memory_resource() noexcept;
// The default memory resource
memory_resource* set_default_resource(memory_resource* r) noexcept;
memory_resource* get_default_resource() noexcept;
// Standard memory resources
struct pool_options;
class synchronized_pool_resource;
class unsynchronized_pool_resource;
class monotonic_buffer_resource;
} // namespace pmr
} // namespace fundamentals_v1
} // namespace experimental
} // namespace std
*/
#include <experimental/__config>
#include <experimental/__memory>
#include <limits>
#include <memory>
#include <new>
#include <stdexcept>
#include <__tuple>
#include <type_traits>
#include <utility>
#include <cstddef>
#include <cstdlib>
#include <__debug>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
// Round __s up to next multiple of __a.
inline _LIBCPP_INLINE_VISIBILITY
size_t __aligned_allocation_size(size_t __s, size_t __a) _NOEXCEPT
{
_LIBCPP_ASSERT(__s + __a > __s, "aligned allocation size overflows");
return (__s + __a - 1) & ~(__a - 1);
}
// 8.5, memory.resource
class _LIBCPP_TYPE_VIS memory_resource
{
static const size_t __max_align = _LIBCPP_ALIGNOF(max_align_t);
// 8.5.2, memory.resource.public
public:
virtual ~memory_resource() = default;
_LIBCPP_INLINE_VISIBILITY
void* allocate(size_t __bytes, size_t __align = __max_align)
{ return do_allocate(__bytes, __align); }
_LIBCPP_INLINE_VISIBILITY
void deallocate(void * __p, size_t __bytes, size_t __align = __max_align)
{ do_deallocate(__p, __bytes, __align); }
_LIBCPP_INLINE_VISIBILITY
bool is_equal(memory_resource const & __other) const _NOEXCEPT
{ return do_is_equal(__other); }
// 8.5.3, memory.resource.priv
protected:
virtual void* do_allocate(size_t, size_t) = 0;
virtual void do_deallocate(void*, size_t, size_t) = 0;
virtual bool do_is_equal(memory_resource const &) const _NOEXCEPT = 0;
};
// 8.5.4, memory.resource.eq
inline _LIBCPP_INLINE_VISIBILITY
bool operator==(memory_resource const & __lhs,
memory_resource const & __rhs) _NOEXCEPT
{
return &__lhs == &__rhs || __lhs.is_equal(__rhs);
}
inline _LIBCPP_INLINE_VISIBILITY
bool operator!=(memory_resource const & __lhs,
memory_resource const & __rhs) _NOEXCEPT
{
return !(__lhs == __rhs);
}
_LIBCPP_FUNC_VIS
memory_resource * new_delete_resource() _NOEXCEPT;
_LIBCPP_FUNC_VIS
memory_resource * null_memory_resource() _NOEXCEPT;
_LIBCPP_FUNC_VIS
memory_resource * get_default_resource() _NOEXCEPT;
_LIBCPP_FUNC_VIS
memory_resource * set_default_resource(memory_resource * __new_res) _NOEXCEPT;
// 8.6, memory.polymorphic.allocator.class
// 8.6.1, memory.polymorphic.allocator.overview
template <class _ValueType>
class _LIBCPP_TEMPLATE_VIS polymorphic_allocator
{
public:
typedef _ValueType value_type;
// 8.6.2, memory.polymorphic.allocator.ctor
_LIBCPP_INLINE_VISIBILITY
polymorphic_allocator() _NOEXCEPT
: __res_(_VSTD_LFTS_PMR::get_default_resource())
{}
_LIBCPP_INLINE_VISIBILITY
polymorphic_allocator(memory_resource * __r) _NOEXCEPT
: __res_(__r)
{}
polymorphic_allocator(polymorphic_allocator const &) = default;
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY
polymorphic_allocator(polymorphic_allocator<_Tp> const & __other) _NOEXCEPT
: __res_(__other.resource())
{}
polymorphic_allocator &
operator=(polymorphic_allocator const &) = delete;
// 8.6.3, memory.polymorphic.allocator.mem
_LIBCPP_INLINE_VISIBILITY
_ValueType* allocate(size_t __n) {
if (__n > __max_size()) {
__throw_length_error(
"std::experimental::pmr::polymorphic_allocator<T>::allocate(size_t n)"
" 'n' exceeds maximum supported size");
}
return static_cast<_ValueType*>(
__res_->allocate(__n * sizeof(_ValueType), _LIBCPP_ALIGNOF(_ValueType))
);
}
_LIBCPP_INLINE_VISIBILITY
void deallocate(_ValueType * __p, size_t __n) _NOEXCEPT {
_LIBCPP_ASSERT(__n <= __max_size(),
"deallocate called for size which exceeds max_size()");
__res_->deallocate(__p, __n * sizeof(_ValueType), _LIBCPP_ALIGNOF(_ValueType));
}
template <class _Tp, class ..._Ts>
_LIBCPP_INLINE_VISIBILITY
void construct(_Tp* __p, _Ts &&... __args)
{
_VSTD_LFTS::__lfts_user_alloc_construct(
__p, *this, _VSTD::forward<_Ts>(__args)...
);
}
template <class _T1, class _T2, class ..._Args1, class ..._Args2>
_LIBCPP_INLINE_VISIBILITY
void construct(pair<_T1, _T2>* __p, piecewise_construct_t,
tuple<_Args1...> __x, tuple<_Args2...> __y)
{
::new ((void*)__p) pair<_T1, _T2>(piecewise_construct
, __transform_tuple(
typename __lfts_uses_alloc_ctor<
_T1, polymorphic_allocator&, _Args1...
>::type()
, _VSTD::move(__x)
, typename __make_tuple_indices<sizeof...(_Args1)>::type{}
)
, __transform_tuple(
typename __lfts_uses_alloc_ctor<
_T2, polymorphic_allocator&, _Args2...
>::type()
, _VSTD::move(__y)
, typename __make_tuple_indices<sizeof...(_Args2)>::type{}
)
);
}
template <class _T1, class _T2>
_LIBCPP_INLINE_VISIBILITY
void construct(pair<_T1, _T2>* __p) {
construct(__p, piecewise_construct, tuple<>(), tuple<>());
}
template <class _T1, class _T2, class _Up, class _Vp>
_LIBCPP_INLINE_VISIBILITY
void construct(pair<_T1, _T2> * __p, _Up && __u, _Vp && __v) {
construct(__p, piecewise_construct
, _VSTD::forward_as_tuple(_VSTD::forward<_Up>(__u))
, _VSTD::forward_as_tuple(_VSTD::forward<_Vp>(__v)));
}
template <class _T1, class _T2, class _U1, class _U2>
_LIBCPP_INLINE_VISIBILITY
void construct(pair<_T1, _T2> * __p, pair<_U1, _U2> const & __pr) {
construct(__p, piecewise_construct
, _VSTD::forward_as_tuple(__pr.first)
, _VSTD::forward_as_tuple(__pr.second));
}
template <class _T1, class _T2, class _U1, class _U2>
_LIBCPP_INLINE_VISIBILITY
void construct(pair<_T1, _T2> * __p, pair<_U1, _U2> && __pr){
construct(__p, piecewise_construct
, _VSTD::forward_as_tuple(_VSTD::forward<_U1>(__pr.first))
, _VSTD::forward_as_tuple(_VSTD::forward<_U2>(__pr.second)));
}
template <class _Tp>
_LIBCPP_INLINE_VISIBILITY
void destroy(_Tp * __p) _NOEXCEPT
{ __p->~_Tp(); }
_LIBCPP_INLINE_VISIBILITY
polymorphic_allocator
select_on_container_copy_construction() const _NOEXCEPT
{ return polymorphic_allocator(); }
_LIBCPP_INLINE_VISIBILITY
memory_resource * resource() const _NOEXCEPT
{ return __res_; }
private:
template <class ..._Args, size_t ..._Idx>
_LIBCPP_INLINE_VISIBILITY
tuple<_Args&&...>
__transform_tuple(integral_constant<int, 0>, tuple<_Args...>&& __t,
__tuple_indices<_Idx...>) const
{
return _VSTD::forward_as_tuple(_VSTD::get<_Idx>(_VSTD::move(__t))...);
}
template <class ..._Args, size_t ..._Idx>
_LIBCPP_INLINE_VISIBILITY
tuple<allocator_arg_t const&, polymorphic_allocator&, _Args&&...>
__transform_tuple(integral_constant<int, 1>, tuple<_Args...> && __t,
__tuple_indices<_Idx...>)
{
using _Tup = tuple<allocator_arg_t const&, polymorphic_allocator&, _Args&&...>;
return _Tup(allocator_arg, *this,
_VSTD::get<_Idx>(_VSTD::move(__t))...);
}
template <class ..._Args, size_t ..._Idx>
_LIBCPP_INLINE_VISIBILITY
tuple<_Args&&..., polymorphic_allocator&>
__transform_tuple(integral_constant<int, 2>, tuple<_Args...> && __t,
__tuple_indices<_Idx...>)
{
using _Tup = tuple<_Args&&..., polymorphic_allocator&>;
return _Tup(_VSTD::get<_Idx>(_VSTD::move(__t))..., *this);
}
_LIBCPP_INLINE_VISIBILITY
size_t __max_size() const _NOEXCEPT
{ return numeric_limits<size_t>::max() / sizeof(value_type); }
memory_resource * __res_;
};
// 8.6.4, memory.polymorphic.allocator.eq
template <class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
bool operator==(polymorphic_allocator<_Tp> const & __lhs,
polymorphic_allocator<_Up> const & __rhs) _NOEXCEPT
{
return *__lhs.resource() == *__rhs.resource();
}
template <class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
bool operator!=(polymorphic_allocator<_Tp> const & __lhs,
polymorphic_allocator<_Up> const & __rhs) _NOEXCEPT
{
return !(__lhs == __rhs);
}
// 8.7, memory.resource.adaptor
// 8.7.1, memory.resource.adaptor.overview
template <class _CharAlloc>
class _LIBCPP_TEMPLATE_VIS __resource_adaptor_imp
: public memory_resource
{
using _CTraits = allocator_traits<_CharAlloc>;
static_assert(is_same<typename _CTraits::value_type, char>::value
&& is_same<typename _CTraits::pointer, char*>::value
&& is_same<typename _CTraits::void_pointer, void*>::value, "");
static const size_t _MaxAlign = _LIBCPP_ALIGNOF(max_align_t);
using _Alloc = typename _CTraits::template rebind_alloc<
typename aligned_storage<_MaxAlign, _MaxAlign>::type
>;
using _ValueType = typename _Alloc::value_type;
_Alloc __alloc_;
public:
typedef _CharAlloc allocator_type;
__resource_adaptor_imp() = default;
__resource_adaptor_imp(__resource_adaptor_imp const &) = default;
__resource_adaptor_imp(__resource_adaptor_imp &&) = default;
// 8.7.2, memory.resource.adaptor.ctor
_LIBCPP_INLINE_VISIBILITY
explicit __resource_adaptor_imp(allocator_type const & __a)
: __alloc_(__a)
{}
_LIBCPP_INLINE_VISIBILITY
explicit __resource_adaptor_imp(allocator_type && __a)
: __alloc_(_VSTD::move(__a))
{}
__resource_adaptor_imp &
operator=(__resource_adaptor_imp const &) = default;
_LIBCPP_INLINE_VISIBILITY
allocator_type get_allocator() const
{ return __alloc_; }
// 8.7.3, memory.resource.adaptor.mem
protected:
virtual void * do_allocate(size_t __bytes, size_t)
{
if (__bytes > __max_size()) {
__throw_length_error(
"std::experimental::pmr::resource_adaptor<T>::do_allocate(size_t bytes, size_t align)"
" 'bytes' exceeds maximum supported size");
}
size_t __s = __aligned_allocation_size(__bytes, _MaxAlign) / _MaxAlign;
return __alloc_.allocate(__s);
}
virtual void do_deallocate(void * __p, size_t __bytes, size_t)
{
_LIBCPP_ASSERT(__bytes <= __max_size(),
"do_deallocate called for size which exceeds the maximum allocation size");
size_t __s = __aligned_allocation_size(__bytes, _MaxAlign) / _MaxAlign;
__alloc_.deallocate((_ValueType*)__p, __s);
}
virtual bool do_is_equal(memory_resource const & __other) const _NOEXCEPT {
__resource_adaptor_imp const * __p
= dynamic_cast<__resource_adaptor_imp const *>(&__other);
return __p ? __alloc_ == __p->__alloc_ : false;
}
private:
_LIBCPP_INLINE_VISIBILITY
size_t __max_size() const _NOEXCEPT {
return numeric_limits<size_t>::max() - _MaxAlign;
}
};
template <class _Alloc>
using resource_adaptor = __resource_adaptor_imp<
typename allocator_traits<_Alloc>::template rebind_alloc<char>
>;
_LIBCPP_END_NAMESPACE_LFTS_PMR
_LIBCPP_POP_MACROS
#endif /* _LIBCPP_EXPERIMENTAL_MEMORY_RESOURCE */