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alignedallocator.hh
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// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
// vi: set et ts=4 sw=4 sts=4:
#ifndef EWOMS_ALIGNED_ALLOCATOR_HH
#define EWOMS_ALIGNED_ALLOCATOR_HH
#include <cassert>
#include <cstdlib>
#include <memory>
#include <type_traits>
#include <utility>
namespace Opm {
namespace detail {
constexpr inline bool is_alignment(std::size_t value) noexcept
{
return (value > 0) && ((value & (value - 1)) == 0);
}
template<std::size_t N>
struct is_alignment_constant
: std::integral_constant<bool, (N > 0) && ((N & (N - 1)) == 0)>
{};
template<std::size_t A, std::size_t B>
struct min_size
: std::integral_constant<std::size_t, (A < B) ? A : B>
{};
template<class T>
struct offset_object
{
char offset;
T object;
};
template<class T>
struct alignment_of
: min_size<sizeof(T), sizeof(offset_object<T>) - sizeof(T)>::type
{};
template<std::size_t A, std::size_t B>
struct max_align
: std::integral_constant<std::size_t,(A > B) ? A : B>
{};
template<class T>
struct max_count_of
: std::integral_constant<std::size_t, ~static_cast<std::size_t>(0) / sizeof(T)>
{};
using std::addressof;
}
inline void* aligned_alloc(std::size_t alignment,
std::size_t size) noexcept
{
assert(detail::is_alignment(alignment));
if (alignment < sizeof(void*)) {
alignment = sizeof(void*);
}
void* p;
if (::posix_memalign(&p, alignment, size) != 0) {
p = 0;
}
return p;
}
inline void aligned_free(void* ptr)
noexcept
{
::free(ptr);
}
template<class T, std::size_t Alignment>
class aligned_allocator
{
static_assert(detail::is_alignment_constant<Alignment>::value, "Alignment must be powers of two!");
public:
using value_type = T;
using pointer = T*;
using const_pointer = const T*;
using void_pointer = void*;
using const_void_pointer = const void*;
using size_type = std::size_t;
using difference_type = std::ptrdiff_t;
using reference = T&;
using const_reference = const T&;
private:
using MaxAlign = detail::max_align<Alignment, detail::alignment_of<value_type>::value>;
public:
template<class U>
struct rebind
{
using other = aligned_allocator<U, Alignment>;
};
aligned_allocator() noexcept = default;
template<class U>
aligned_allocator(const aligned_allocator<U,
Alignment>&) noexcept
{}
pointer address(reference value) const noexcept
{
return detail::addressof(value);
}
const_pointer address(const_reference value) const noexcept
{
return detail::addressof(value);
}
pointer allocate(size_type size,
const_void_pointer = 0)
{
void* p = aligned_alloc(MaxAlign::value,
sizeof(T) * size);
if (!p && size > 0) {
throw std::bad_alloc();
}
return static_cast<T*>(p);
}
void deallocate(pointer ptr, size_type)
{
aligned_free(ptr);
}
constexpr size_type max_size() const noexcept
{
return detail::max_count_of<T>::value;
}
template<class U, class... Args>
void construct(U* ptr, Args&&... args)
{
void* p = ptr;
::new(p) U(std::forward<Args>(args)...);
}
template<class U>
void construct(U* ptr)
{
void* p = ptr;
::new(p) U();
}
template<class U>
void destroy(U* ptr)
{
(void)ptr;
ptr->~U();
}
};
template<std::size_t Alignment>
class aligned_allocator<void, Alignment>
{
static_assert(detail::is_alignment_constant<Alignment>::value,
"The specified alignment is not a power of two!");
public:
using value_type = void;
using pointer = void*;
using const_pointer = const void*;
template<class U>
struct rebind
{
using other = aligned_allocator<U, Alignment>;
};
};
template<class T1, class T2, std::size_t Alignment>
inline bool operator==(const aligned_allocator<T1,
Alignment>&, const aligned_allocator<T2,
Alignment>&) noexcept
{
return true;
}
template<class T1, class T2, std::size_t Alignment>
inline bool operator!=(const aligned_allocator<T1,
Alignment>&, const aligned_allocator<T2,
Alignment>&) noexcept
{
return false;
}
}
#endif
Opm::aligned_allocator
Definition alignedallocator.hh:97
Opm
This file contains a set of helper functions used by VFPProd / VFPInj.
Definition blackoilbioeffectsmodules.hh:43
Opm::aligned_allocator::rebind
Definition alignedallocator.hh:117
Opm::aligned_allocator< void, Alignment >::rebind
Definition alignedallocator.hh:194
Opm::detail::is_alignment_constant
Definition alignedallocator.hh:42
Opm::detail::max_align
Definition alignedallocator.hh:64
Opm::detail::max_count_of
Definition alignedallocator.hh:69
Opm::detail::min_size
Definition alignedallocator.hh:47