1 //===--------------------- mutex_destructor.cpp ---------------------------===// 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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // Define ~mutex. 10 // 11 // On some platforms ~mutex has been made trivial and the definition is only 12 // provided for ABI compatibility. 13 // 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. 18 19 #include "__config" 20 #include "__threading_support" 21 22 #if !defined(_LIBCPP_HAS_NO_THREADS) 23 #if _LIBCPP_ABI_VERSION == 1 || !defined(_LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION) 24 #define NEEDS_MUTEX_DESTRUCTOR 25 #endif 26 #endif 27 28 _LIBCPP_BEGIN_NAMESPACE_STD 29 30 #ifdef NEEDS_MUTEX_DESTRUCTOR 31 class _LIBCPP_TYPE_VIS mutex 32 { 33 __libcpp_mutex_t __m_ = _LIBCPP_MUTEX_INITIALIZER; 34 35 public: 36 _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY 37 constexpr mutex() = default; 38 mutex(const mutex&) = delete; 39 mutex& operator=(const mutex&) = delete; 40 ~mutex() noexcept; 41 }; 42 43 44 mutex::~mutex() _NOEXCEPT 45 { 46 __libcpp_mutex_destroy(&__m_); 47 } 48 49 #endif // !_LIBCPP_HAS_NO_THREADS 50 _LIBCPP_END_NAMESPACE_STD 51