| // Allocator that wraps "C" malloc -*- C++ -*- |
| |
| // Copyright (C) 2001-2020 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 ext/malloc_allocator.h |
| * This file is a GNU extension to the Standard C++ Library. |
| */ |
| |
| #ifndef _MALLOC_ALLOCATOR_H |
| #define _MALLOC_ALLOCATOR_H 1 |
| |
| #include <cstdlib> |
| #include <cstddef> |
| #include <new> |
| #include <bits/functexcept.h> |
| #include <bits/move.h> |
| #if __cplusplus >= 201103L |
| #include <type_traits> |
| #endif |
| |
| namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| /** |
| * @brief An allocator that uses malloc. |
| * @ingroup allocators |
| * |
| * This is precisely the allocator defined in the C++ Standard. |
| * - all allocation calls malloc |
| * - all deallocation calls free |
| */ |
| template<typename _Tp> |
| class malloc_allocator |
| { |
| public: |
| typedef _Tp value_type; |
| typedef std::size_t size_type; |
| typedef std::ptrdiff_t difference_type; |
| #if __cplusplus <= 201703L |
| typedef _Tp* pointer; |
| typedef const _Tp* const_pointer; |
| typedef _Tp& reference; |
| typedef const _Tp& const_reference; |
| |
| template<typename _Tp1> |
| struct rebind |
| { typedef malloc_allocator<_Tp1> other; }; |
| #endif |
| |
| #if __cplusplus >= 201103L |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // 2103. propagate_on_container_move_assignment |
| typedef std::true_type propagate_on_container_move_assignment; |
| #endif |
| |
| _GLIBCXX20_CONSTEXPR |
| malloc_allocator() _GLIBCXX_USE_NOEXCEPT { } |
| |
| _GLIBCXX20_CONSTEXPR |
| malloc_allocator(const malloc_allocator&) _GLIBCXX_USE_NOEXCEPT { } |
| |
| template<typename _Tp1> |
| _GLIBCXX20_CONSTEXPR |
| malloc_allocator(const malloc_allocator<_Tp1>&) |
| _GLIBCXX_USE_NOEXCEPT { } |
| |
| #if __cplusplus <= 201703L |
| ~malloc_allocator() _GLIBCXX_USE_NOEXCEPT { } |
| |
| pointer |
| address(reference __x) const _GLIBCXX_NOEXCEPT |
| { return std::__addressof(__x); } |
| |
| const_pointer |
| address(const_reference __x) const _GLIBCXX_NOEXCEPT |
| { return std::__addressof(__x); } |
| #endif |
| |
| // NB: __n is permitted to be 0. The C++ standard says nothing |
| // about what the return value is when __n == 0. |
| _GLIBCXX_NODISCARD _Tp* |
| allocate(size_type __n, const void* = 0) |
| { |
| #if __cplusplus >= 201103L |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // 3308. std::allocator<void>().allocate(n) |
| static_assert(sizeof(_Tp) != 0, "cannot allocate incomplete types"); |
| #endif |
| |
| if (__n > this->_M_max_size()) |
| std::__throw_bad_alloc(); |
| |
| _Tp* __ret = 0; |
| #if __cpp_aligned_new |
| #if __cplusplus > 201402L && _GLIBCXX_HAVE_ALIGNED_ALLOC |
| if (alignof(_Tp) > alignof(std::max_align_t)) |
| { |
| __ret = static_cast<_Tp*>(::aligned_alloc(alignof(_Tp), |
| __n * sizeof(_Tp))); |
| } |
| #else |
| # define _GLIBCXX_CHECK_MALLOC_RESULT |
| #endif |
| #endif |
| if (!__ret) |
| __ret = static_cast<_Tp*>(std::malloc(__n * sizeof(_Tp))); |
| if (!__ret) |
| std::__throw_bad_alloc(); |
| #ifdef _GLIBCXX_CHECK_MALLOC_RESULT |
| #undef _GLIBCXX_CHECK_MALLOC_RESULT |
| if (reinterpret_cast<std::size_t>(__ret) % alignof(_Tp)) |
| { |
| // Memory returned by malloc is not suitably aligned for _Tp. |
| deallocate(__ret, __n); |
| std::__throw_bad_alloc(); |
| } |
| #endif |
| return __ret; |
| } |
| |
| // __p is not permitted to be a null pointer. |
| void |
| deallocate(_Tp* __p, size_type) |
| { std::free(static_cast<void*>(__p)); } |
| |
| #if __cplusplus <= 201703L |
| size_type |
| max_size() const _GLIBCXX_USE_NOEXCEPT |
| { return _M_max_size(); } |
| |
| #if __cplusplus >= 201103L |
| template<typename _Up, typename... _Args> |
| void |
| construct(_Up* __p, _Args&&... __args) |
| noexcept(std::is_nothrow_constructible<_Up, _Args...>::value) |
| { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); } |
| |
| template<typename _Up> |
| void |
| destroy(_Up* __p) |
| noexcept(std::is_nothrow_destructible<_Up>::value) |
| { __p->~_Up(); } |
| #else |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // 402. wrong new expression in [some_] allocator::construct |
| void |
| construct(pointer __p, const _Tp& __val) |
| { ::new((void *)__p) value_type(__val); } |
| |
| void |
| destroy(pointer __p) { __p->~_Tp(); } |
| #endif |
| #endif // ! C++20 |
| |
| template<typename _Up> |
| friend _GLIBCXX20_CONSTEXPR bool |
| operator==(const malloc_allocator&, const malloc_allocator<_Up>&) |
| _GLIBCXX_NOTHROW |
| { return true; } |
| |
| #if __cpp_impl_three_way_comparison < 201907L |
| template<typename _Up> |
| friend _GLIBCXX20_CONSTEXPR bool |
| operator!=(const malloc_allocator&, const malloc_allocator<_Up>&) |
| _GLIBCXX_NOTHROW |
| { return false; } |
| #endif |
| |
| private: |
| _GLIBCXX_CONSTEXPR size_type |
| _M_max_size() const _GLIBCXX_USE_NOEXCEPT |
| { |
| #if __PTRDIFF_MAX__ < __SIZE_MAX__ |
| return std::size_t(__PTRDIFF_MAX__) / sizeof(_Tp); |
| #else |
| return std::size_t(-1) / sizeof(_Tp); |
| #endif |
| } |
| }; |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace |
| |
| #endif |