43 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// Define ~mutex.10//11// On some platforms ~mutex has been made trivial and the definition is only12// provided for ABI compatibility.13//14// In order to avoid ODR violations within libc++ itself, we need to ensure15// that *nothing* sees the non-trivial mutex declaration. For this reason16// we re-declare the entire class in this file instead of using17// _LIBCPP_BUILDING_LIBRARY to change the definition in the headers.18 19#include <__config>20#include <__thread/support.h>21 22#if _LIBCPP_ABI_VERSION == 1 || !_LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION23# define NEEDS_MUTEX_DESTRUCTOR24#endif25 26_LIBCPP_BEGIN_NAMESPACE_STD27 28#ifdef NEEDS_MUTEX_DESTRUCTOR29class _LIBCPP_EXPORTED_FROM_ABI mutex {30 __libcpp_mutex_t __m_ = _LIBCPP_MUTEX_INITIALIZER;31 32public:33 _LIBCPP_ALWAYS_INLINE _LIBCPP_HIDE_FROM_ABI constexpr mutex() = default;34 mutex(const mutex&) = delete;35 mutex& operator=(const mutex&) = delete;36 ~mutex() noexcept;37};38 39mutex::~mutex() noexcept { __libcpp_mutex_destroy(&__m_); }40#endif // !NEEDS_MUTEX_DESTRUCTOR41 42_LIBCPP_END_NAMESPACE_STD43