xref: /freebsd/contrib/llvm-project/libcxx/include/__mutex/lock_guard.h (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef _LIBCPP___MUTEX_LOCK_GUARD_H
10 #define _LIBCPP___MUTEX_LOCK_GUARD_H
11 
12 #include <__config>
13 #include <__mutex/tag_types.h>
14 
15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
16 #  pragma GCC system_header
17 #endif
18 
19 #ifndef _LIBCPP_HAS_NO_THREADS
20 
21 _LIBCPP_BEGIN_NAMESPACE_STD
22 
23 template <class _Mutex>
24 class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable) lock_guard {
25 public:
26   typedef _Mutex mutex_type;
27 
28 private:
29   mutex_type& __m_;
30 
31 public:
32   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI explicit lock_guard(mutex_type& __m)
33       _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
34       : __m_(__m) {
35     __m_.lock();
36   }
37 
38   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI lock_guard(mutex_type& __m, adopt_lock_t)
39       _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
40       : __m_(__m) {}
41   _LIBCPP_HIDE_FROM_ABI ~lock_guard() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) { __m_.unlock(); }
42 
43 private:
44   lock_guard(lock_guard const&)            = delete;
45   lock_guard& operator=(lock_guard const&) = delete;
46 };
47 _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(lock_guard);
48 
49 _LIBCPP_END_NAMESPACE_STD
50 
51 #endif // _LIBCPP_HAS_NO_THREADS
52 
53 #endif // _LIBCPP___MUTEX_LOCK_GUARD_H
54