sled/3party/asyncplusplus/include/async++/aligned_alloc.h
2024-03-27 23:16:26 +08:00

100 lines
2.7 KiB
C++

// Copyright (c) 2015 Amanieu d'Antras
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
namespace async {
namespace detail {
// Allocate an aligned block of memory
LIBASYNC_EXPORT void* aligned_alloc(std::size_t size, std::size_t align);
// Free an aligned block of memory
LIBASYNC_EXPORT void aligned_free(void* addr) LIBASYNC_NOEXCEPT;
// Class representing an aligned array and its length
template<typename T, std::size_t Align = std::alignment_of<T>::value>
class aligned_array {
std::size_t length;
T* ptr;
public:
aligned_array()
: length(0), ptr(nullptr) {}
aligned_array(std::nullptr_t)
: length(0), ptr(nullptr) {}
explicit aligned_array(std::size_t length_)
: length(length_)
{
ptr = static_cast<T*>(aligned_alloc(length * sizeof(T), Align));
std::size_t i;
LIBASYNC_TRY {
for (i = 0; i < length; i++)
new(ptr + i) T;
} LIBASYNC_CATCH(...) {
for (std::size_t j = 0; j < i; j++)
ptr[i].~T();
aligned_free(ptr);
LIBASYNC_RETHROW();
}
}
aligned_array(aligned_array&& other) LIBASYNC_NOEXCEPT
: length(other.length), ptr(other.ptr)
{
other.ptr = nullptr;
other.length = 0;
}
aligned_array& operator=(aligned_array&& other) LIBASYNC_NOEXCEPT
{
aligned_array(std::move(*this));
std::swap(ptr, other.ptr);
std::swap(length, other.length);
return *this;
}
aligned_array& operator=(std::nullptr_t)
{
return *this = aligned_array();
}
~aligned_array()
{
for (std::size_t i = 0; i < length; i++)
ptr[i].~T();
aligned_free(ptr);
}
T& operator[](std::size_t i) const
{
return ptr[i];
}
std::size_t size() const
{
return length;
}
T* get() const
{
return ptr;
}
explicit operator bool() const
{
return ptr != nullptr;
}
};
} // namespace detail
} // namespace async