v1/__mutex/lock_guard.h

0001 //===----------------------------------------------------------------------===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef _LIBCPP___MUTEX_LOCK_GUARD_H
0010 #define _LIBCPP___MUTEX_LOCK_GUARD_H
0011
0012 #include <__config>
0013 #include <__mutex/tag_types.h>
0014
0015 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
0016 #  pragma GCC system_header
0017 #endif
0018
0019 _LIBCPP_BEGIN_NAMESPACE_STD
0020
0021 template <class _Mutex>
0022 class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable) lock_guard {
0023 public:
0024   typedef _Mutex mutex_type;
0025
0026 private:
0027   mutex_type& __m_;
0028
0029 public:
0030   [[__nodiscard__]]
0031   _LIBCPP_HIDE_FROM_ABI explicit lock_guard(mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
0032       : __m_(__m) {
0033     __m_.lock();
0034   }
0035
0036   [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI lock_guard(mutex_type& __m, adopt_lock_t)
0037       _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
0038       : __m_(__m) {}
0039   _LIBCPP_HIDE_FROM_ABI ~lock_guard() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) { __m_.unlock(); }
0040
0041   lock_guard(lock_guard const&)            = delete;
0042   lock_guard& operator=(lock_guard const&) = delete;
0043 };
0044 _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(lock_guard);
0045
0046 _LIBCPP_END_NAMESPACE_STD
0047
0048 #endif // _LIBCPP___MUTEX_LOCK_GUARD_H