Upgrade to 2022-era LLVM LIBCXX

third_party/libcxx/__mutex/mutex.h

@@ -0,0 +1,53 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___MUTEX_MUTEX_H
+#define _LIBCPP___MUTEX_MUTEX_H
+
+#include <__config>
+#include <__threading_support>
+#include <__type_traits/is_nothrow_default_constructible.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#ifndef _LIBCPP_HAS_NO_THREADS
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+class _LIBCPP_TYPE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(capability("mutex")) mutex {
+  __libcpp_mutex_t __m_ = _LIBCPP_MUTEX_INITIALIZER;
+
+public:
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR mutex() = default;
+
+  mutex(const mutex&)            = delete;
+  mutex& operator=(const mutex&) = delete;
+
+#  if defined(_LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION)
+  _LIBCPP_HIDE_FROM_ABI ~mutex() = default;
+#  else
+  ~mutex() _NOEXCEPT;
+#  endif
+
+  void lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability());
+  bool try_lock() _NOEXCEPT _LIBCPP_THREAD_SAFETY_ANNOTATION(try_acquire_capability(true));
+  void unlock() _NOEXCEPT _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability());
+
+  typedef __libcpp_mutex_t* native_handle_type;
+  _LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() { return &__m_; }
+};
+
+static_assert(is_nothrow_default_constructible<mutex>::value, "the default constructor for std::mutex must be nothrow");
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_HAS_NO_THREADS
+
+#endif // _LIBCPP___MUTEX_MUTEX_H