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 #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