1 //===--------------------- mutex_destructor.cpp ---------------------------===//
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-exception
7 //===----------------------------------------------------------------------===//
11 // On some platforms ~mutex has been made trivial and the definition is only
12 // provided for ABI compatibility.
14 // In order to avoid ODR violations within libc++ itself, we need to ensure
15 // that *nothing* sees the non-trivial mutex declaration. For this reason
16 // we re-declare the entire class in this file instead of using
17 // _LIBCPP_BUILDING_LIBRARY to change the definition in the headers.
20 #include "__threading_support"
22 #if !defined(_LIBCPP_HAS_NO_THREADS)
23 #if _LIBCPP_ABI_VERSION == 1 || !defined(_LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION)
24 #define NEEDS_MUTEX_DESTRUCTOR
28 _LIBCPP_BEGIN_NAMESPACE_STD
30 #ifdef NEEDS_MUTEX_DESTRUCTOR
31 class _LIBCPP_TYPE_VIS mutex
33 __libcpp_mutex_t __m_ = _LIBCPP_MUTEX_INITIALIZER;
36 _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
37 constexpr mutex() = default;
38 mutex(const mutex&) = delete;
39 mutex& operator=(const mutex&) = delete;
44 mutex::~mutex() _NOEXCEPT
46 __libcpp_mutex_destroy(&__m_);
49 #endif // !_LIBCPP_HAS_NO_THREADS
50 _LIBCPP_END_NAMESPACE_STD