libcxx/include/__mutex/lock_guard.h

   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 _LIBCPP_BEGIN_NAMESPACE_STD
  20
  21 template <class _Mutex>
  22 class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable) lock_guard {
  23 public:
  24   typedef _Mutex mutex_type;
  25
  26 private:
  27   mutex_type& __m_;
  28
  29 public:
  30   [[__nodiscard__]]
  31   _LIBCPP_HIDE_FROM_ABI explicit lock_guard(mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
  32       : __m_(__m) {
  33     __m_.lock();
  34   }
  35
  36   [[__nodiscard__]] _LIBCPP_HIDE_FROM_ABI lock_guard(mutex_type& __m, adopt_lock_t)
  37       _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
  38       : __m_(__m) {}
  39   _LIBCPP_HIDE_FROM_ABI ~lock_guard() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) { __m_.unlock(); }
  40
  41   lock_guard(lock_guard const&)            = delete;
  42   lock_guard& operator=(lock_guard const&) = delete;
  43 };
  44 _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(lock_guard);
  45
  46 _LIBCPP_END_NAMESPACE_STD
  47
  48 #endif // _LIBCPP___MUTEX_LOCK_GUARD_H