Program Listing for File dynamic_stack.hpp
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)
#ifndef VEG_DYNAMIC_STACK_DYNAMIC_STACK_HPP_UBOMZFTOS
#define VEG_DYNAMIC_STACK_DYNAMIC_STACK_HPP_UBOMZFTOS
#include "proxsuite/fwd.hpp"
#include "proxsuite/linalg/veg/util/assert.hpp"
#include "proxsuite/linalg/veg/internal/collection_algo.hpp"
#include "proxsuite/linalg/veg/memory/alloc.hpp"
#include "proxsuite/linalg/veg/memory/placement.hpp"
#include "proxsuite/linalg/veg/slice.hpp"
#include "proxsuite/linalg/veg/type_traits/constructible.hpp"
#include "proxsuite/linalg/veg/memory/placement.hpp"
#include "proxsuite/linalg/veg/memory/address.hpp"
#include "proxsuite/linalg/veg/internal/narrow.hpp"
#include "proxsuite/linalg/veg/internal/prologue.hpp"
namespace proxsuite {
namespace linalg {
namespace veg {
namespace _detail {
namespace _dynstack {
constexpr auto
max2(isize a, isize b) noexcept -> isize
{
return (a > b) ? a : b;
}
constexpr auto
round_up_pow2(isize a, isize b) noexcept -> isize
{
return isize((usize(a) + ~(0 - usize(b))) & (0 - usize(b)));
}
} // namespace _dynstack
} // namespace _detail
namespace dynstack {
struct StackReq
{
isize size_bytes;
isize align;
constexpr friend auto operator==(StackReq a, StackReq b) noexcept -> bool
{
return a.size_bytes == b.size_bytes && a.align == b.align;
}
constexpr friend auto operator&(StackReq a, StackReq b) noexcept -> StackReq
{
using namespace _detail::_dynstack;
return {
round_up_pow2( //
round_up_pow2( //
a.size_bytes,
b.align) +
b.size_bytes,
(max2)(a.align, b.align)),
(max2)(a.align, b.align),
};
}
constexpr friend auto operator|(StackReq a, StackReq b) noexcept -> StackReq
{
using namespace _detail::_dynstack;
return {
(max2)( //
round_up_pow2(a.size_bytes, max2(a.align, b.align)),
round_up_pow2(b.size_bytes, max2(a.align, b.align))),
(max2)(a.align, b.align),
};
}
constexpr auto alloc_req() const noexcept -> isize
{
return size_bytes + align - 1;
}
template<typename T>
static constexpr auto with_len(proxsuite::linalg::veg::Tag<T> /*tag*/,
isize len) noexcept -> StackReq
{
return {
isize{ sizeof(T) } * len,
isize{ alignof(T) },
};
}
static VEG_CPP14(constexpr) auto and_(Slice<StackReq> reqs) noexcept
-> StackReq
{
StackReq req{ 0, 1 };
for (isize i = 0; i < reqs.len(); ++i) {
req = req & reqs.ptr()[i];
}
return req;
}
static VEG_CPP14(constexpr) auto or_(Slice<StackReq> reqs) noexcept
-> StackReq
{
StackReq req{ 0, 1 };
for (isize i = 0; i < reqs.len(); ++i) {
req = req | reqs.ptr()[i];
}
return req;
}
};
template<typename T>
struct DynStackArray;
template<typename T>
struct DynStackAlloc;
} // namespace dynstack
namespace _detail {
// if possible:
// aligns the pointer
// then advances it by `size` bytes, and decreases `space` by `size`
// returns the previous aligned value
//
// otherwise, if there is not enough space for aligning or advancing the
// pointer, returns nullptr and the values are left unmodified
inline auto
align_next(isize alignment, isize size, void*& ptr, isize& space)
VEG_ALWAYS_NOEXCEPT->void*
{
static_assert(sizeof(std::uintptr_t) >= sizeof(void*),
"std::uintptr_t can't hold a pointer value");
using byte_ptr = unsigned char*;
// assert alignment is power of two
VEG_ASSERT_ALL_OF( //
(alignment > isize{ 0 }),
((u64(alignment) & (u64(alignment) - 1)) == u64(0)));
if (space < size) {
return nullptr;
}
std::uintptr_t lo_mask = usize(alignment) - 1;
std::uintptr_t hi_mask = ~lo_mask;
auto const intptr = reinterpret_cast<std::uintptr_t>(ptr);
auto* const byteptr = static_cast<byte_ptr>(ptr);
auto offset = ((intptr + usize(alignment) - 1) & hi_mask) - intptr;
if (usize(space) - usize(size) < offset) {
return nullptr;
}
void* const rv = byteptr + offset;
ptr = byteptr + (offset + usize(size));
space = space - (isize(offset) + (size));
return rv;
}
} // namespace _detail
namespace _detail {
namespace _dynstack {
template<typename T, bool = VEG_CONCEPT(trivially_destructible<T>)>
struct DynStackArrayDtor
{};
template<typename T>
struct DynStackArrayDtor<T, false>
{
DynStackArrayDtor() = default;
DynStackArrayDtor(DynStackArrayDtor const&) = default;
DynStackArrayDtor(DynStackArrayDtor&&) = default;
auto operator=(DynStackArrayDtor const&) -> DynStackArrayDtor& = default;
auto operator=(DynStackArrayDtor&&) -> DynStackArrayDtor& = default;
VEG_INLINE ~DynStackArrayDtor()
VEG_NOEXCEPT_IF(VEG_CONCEPT(nothrow_destructible<T>))
{
auto& self = static_cast<dynstack::DynStackArray<T>&>(*this);
using Base = typename dynstack::DynStackAlloc<T>::Base const&;
proxsuite::linalg::veg::_detail::_collections::backward_destroy(
mut(mem::SystemAlloc{}),
mut(mem::DefaultCloner{}),
self.ptr_mut(),
self.ptr_mut() + Base(self).len);
}
};
struct cleanup;
struct DynAllocBase;
struct default_init_fn
{
template<typename T>
auto make(void* ptr, isize len) -> T*
{
return ::new (ptr) T[usize(len)];
}
};
struct zero_init_fn
{
template<typename T>
auto make(void* ptr, isize len) -> T*
{
return ::new (ptr) T[usize(len)]{};
}
};
struct no_init_fn
{
template<typename T>
auto make(void* ptr, isize len) -> T*
{
return proxsuite::linalg::veg::mem::launder(static_cast<T*>(
static_cast<void*>(::new (ptr) unsigned char[usize(len) * sizeof(T)])));
}
};
} // namespace _dynstack
} // namespace _detail
namespace dynstack {
struct DynStackMut
{
public:
DynStackMut(FromSliceMut /*tag*/, SliceMut<unsigned char> s) VEG_NOEXCEPT
: stack_data(s.ptr_mut())
, stack_bytes(s.len())
{
}
VEG_NODISCARD
auto remaining_bytes() const VEG_NOEXCEPT->isize
{
return isize(stack_bytes);
}
VEG_NODISCARD
auto ptr_mut() const VEG_NOEXCEPT->void* { return stack_data; }
VEG_NODISCARD
auto ptr() const VEG_NOEXCEPT->void const* { return stack_data; }
private:
VEG_INLINE void assert_valid_len(PROXSUITE_MAYBE_UNUSED isize len)
VEG_NOEXCEPT
{
VEG_INTERNAL_ASSERT_PRECONDITIONS(isize(len) >= 0);
}
public:
VEG_TEMPLATE((typename T),
requires VEG_CONCEPT(constructible<T>),
VEG_NODISCARD auto make_new,
(/*unused*/, Tag<T>),
(len, isize),
(align = alignof(T), isize))
VEG_NOEXCEPT_IF(VEG_CONCEPT(nothrow_constructible<T>))->DynStackArray<T>
{
assert_valid_len(len);
DynStackArray<T> get{
*this, isize(len), align, _detail::_dynstack::zero_init_fn{}
};
VEG_ASSERT(get.ptr() != nullptr);
return VEG_FWD(get);
}
VEG_TEMPLATE((typename T),
requires VEG_CONCEPT(constructible<T>),
VEG_NODISCARD auto make_new_for_overwrite,
(/*unused*/, Tag<T>),
(len, isize),
(align = alignof(T), isize))
VEG_NOEXCEPT_IF(VEG_CONCEPT(nothrow_constructible<T>))->DynStackArray<T>
{
assert_valid_len(len);
DynStackArray<T> get{
*this, isize(len), align, _detail::_dynstack::default_init_fn{}
};
VEG_ASSERT(get.ptr() != nullptr);
return VEG_FWD(get);
}
template<typename T>
VEG_NODISCARD auto make_alloc(Tag<T> /*unused*/,
isize len,
isize align = alignof(T))
VEG_NOEXCEPT->DynStackAlloc<T>
{
assert_valid_len(len);
DynStackAlloc<T> get{
*this, isize(len), align, _detail::_dynstack::no_init_fn{}
};
VEG_ASSERT(get.ptr() != nullptr);
return VEG_FWD(get);
}
private:
void* stack_data;
isize stack_bytes;
template<typename T>
friend struct DynStackAlloc;
template<typename T>
friend struct DynStackArray;
friend struct _detail::_dynstack::cleanup;
friend struct _detail::_dynstack::DynAllocBase;
};
} // namespace dynstack
namespace _detail {
namespace _dynstack {
struct cleanup
{
bool const& success;
proxsuite::linalg::veg::dynstack::DynStackMut& parent;
void* old_data;
isize old_rem_bytes;
VEG_INLINE void operator()() const VEG_NOEXCEPT
{
if (!success) {
parent.stack_data = old_data;
parent.stack_bytes = old_rem_bytes;
}
}
};
struct DynAllocBase
{
proxsuite::linalg::veg::dynstack::DynStackMut* parent;
void* old_pos;
void const volatile* data;
isize len;
void destroy(void const volatile* void_data_end) VEG_NOEXCEPT
{
if (data != nullptr) {
// in case resource lifetimes are reodered by moving ownership
PROXSUITE_MAYBE_UNUSED auto* parent_stack_data =
static_cast<unsigned char*>(parent->stack_data);
PROXSUITE_MAYBE_UNUSED auto* old_position =
static_cast<unsigned char*>(old_pos);
PROXSUITE_MAYBE_UNUSED auto* data_end =
static_cast<unsigned char*>(const_cast<void*>(void_data_end));
VEG_INTERNAL_ASSERT_PRECONDITIONS( //
parent_stack_data == data_end,
parent_stack_data >= old_position);
parent->stack_bytes +=
static_cast<isize>(static_cast<unsigned char*>(parent->stack_data) -
static_cast<unsigned char*>(old_pos));
parent->stack_data = old_pos;
}
}
};
} // namespace _dynstack
} // namespace _detail
namespace dynstack {
template<typename T>
struct DynStackAlloc : _detail::_dynstack::DynAllocBase
{
private:
using Base = _detail::_dynstack::DynAllocBase;
public:
VEG_INLINE ~DynStackAlloc() VEG_NOEXCEPT
{
Base::destroy(ptr_mut() + Base::len);
}
DynStackAlloc(DynStackAlloc const&) = delete;
DynStackAlloc(DynStackAlloc&& other) VEG_NOEXCEPT : Base{ Base(other) }
{
other.Base::len = 0;
other.Base::data = nullptr;
};
auto operator=(DynStackAlloc const&) -> DynStackAlloc& = delete;
auto operator=(DynStackAlloc&& rhs) VEG_NOEXCEPT->DynStackAlloc&
{
{
auto cleanup = static_cast<decltype(rhs)>(*this);
}
static_cast<Base&>(*this) = rhs;
static_cast<Base&>(rhs) = {};
return *this;
}
VEG_NODISCARD auto as_mut() VEG_NOEXCEPT->SliceMut<T>
{
return {
unsafe,
FromRawParts{},
ptr_mut(),
len(),
};
}
VEG_NODISCARD auto as_ref() const VEG_NOEXCEPT->Slice<T>
{
return {
unsafe,
FromRawParts{},
ptr(),
len(),
};
}
VEG_NODISCARD auto ptr_mut() VEG_NOEXCEPT->T*
{
return /* NOLINT(clang-analyzer-linalg.uninitialized.UndefReturn) */
static_cast<T*>(const_cast<void*>(Base::data));
}
VEG_NODISCARD auto ptr() const VEG_NOEXCEPT->T const*
{
return /* NOLINT(clang-analyzer-linalg.uninitialized.UndefReturn) */
static_cast<T const*>(const_cast<void const*>(Base::data));
}
VEG_NODISCARD auto len() const VEG_NOEXCEPT->isize
{
return isize(Base::len);
}
private:
friend struct DynStackArray<T>;
friend struct DynStackMut;
friend struct _detail::_dynstack::DynStackArrayDtor<T>;
template<typename Fn>
DynStackAlloc(DynStackMut& parent_ref, isize alloc_size, isize align, Fn fn)
VEG_NOEXCEPT_IF(VEG_CONCEPT(nothrow_constructible<T>))
: Base{
&parent_ref,
parent_ref.stack_data,
nullptr,
0,
}
{
void* const parent_data = parent_ref.stack_data;
isize const parent_bytes = parent_ref.stack_bytes;
void* const ptr = _detail::align_next(align,
alloc_size * isize(sizeof(T)),
parent_ref.stack_data,
parent_ref.stack_bytes);
if (ptr != nullptr) {
bool success = false;
auto&& cleanup = defer(_detail::_dynstack::cleanup{
success, *parent, parent_data, parent_bytes });
(void)cleanup;
Base::len = alloc_size;
Base::data = fn.template make<T>(ptr, alloc_size);
success = true;
}
}
};
template<typename T>
struct DynStackArray
: private // destruction order matters
DynStackAlloc<T>
, _detail::_dynstack::DynStackArrayDtor<T>
{
private:
using Base = _detail::_dynstack::DynAllocBase;
public:
using DynStackAlloc<T>::as_ref;
using DynStackAlloc<T>::as_mut;
using DynStackAlloc<T>::ptr;
using DynStackAlloc<T>::ptr_mut;
using DynStackAlloc<T>::len;
~DynStackArray() = default;
DynStackArray(DynStackArray const&) = delete;
DynStackArray(DynStackArray&&) VEG_NOEXCEPT = default;
auto operator=(DynStackArray const&) -> DynStackArray& = delete;
auto operator=(DynStackArray&& rhs) VEG_NOEXCEPT->DynStackArray&
{
{
auto cleanup = static_cast<decltype(rhs)>(*this);
}
static_cast<Base&>(*this) = rhs;
static_cast<Base&>(rhs) = {};
return *this;
}
private:
using DynStackAlloc<T>::DynStackAlloc;
friend struct DynStackMut;
friend struct _detail::_dynstack::DynStackArrayDtor<T>;
};
} // namespace dynstack
} // namespace veg
} // namespace linalg
} // namespace proxsuite
#include "proxsuite/linalg/veg/internal/epilogue.hpp"
#endif /* end of include guard VEG_DYNAMIC_STACK_DYNAMIC_STACK_HPP_UBOMZFTOS \
*/