[libc++] Granularize __mutex_base

This also updates the moved code to the current style. (i.e. `_VSTD` -> `std`, `_LIBCPP_INLINE_VISIBILITY` -> `_LIBCPP_HIDE_FROM_ABI`, clang-format).

Reviewed By: Mordante, #libc, EricWF

Spies: arichardson, libcxx-commits, mikhail.ramalho

Differential Revision: https://reviews.llvm.org/D146228

Author: philnik777

libcxx/docs/ReleaseNotes.rst

@@ -62,7 +62,8 @@ Deprecations and Removals
   includes are removed based on the language version used. Incidental transitive
   inclusions of the following headers have been removed:
 
-  - C++2b: ``atomic``, ``bit``, ``cstring``, ``type_traits``
+  - C++2b: ``atomic``, ``bit``, ``cstdint``, ``cstdlib``, ``cstring``, ``initializer_list``, ``new``, ``stdexcept``,
+           ``type_traits``, ``typeinfo``
 
 - The headers ``<experimental/algorithm>`` and ``<experimental/functional>`` have been removed, since all the contents
   have been implemented in namespace ``std`` for at least two releases.

libcxx/include/CMakeLists.txt

@@ -294,6 +294,7 @@ set(files
   __concepts/semiregular.h
   __concepts/swappable.h
   __concepts/totally_ordered.h
+  __condition_variable/condition_variable.h
   __config
   __coroutine/coroutine_handle.h
   __coroutine/coroutine_traits.h
@@ -474,7 +475,10 @@ set(files
   __memory_resource/pool_options.h
   __memory_resource/synchronized_pool_resource.h
   __memory_resource/unsynchronized_pool_resource.h
-  __mutex_base
+  __mutex/lock_guard.h
+  __mutex/mutex.h
+  __mutex/tag_types.h
+  __mutex/unique_lock.h
   __node_handle
   __numeric/accumulate.h
   __numeric/adjacent_difference.h

libcxx/include/__condition_variable/condition_variable.h

@@ -0,0 +1,243 @@
+//===----------------------------------------------------------------------===//
+//
+// 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___CONDITION_VARIABLE_CONDITION_VARIABLE_H
+#define _LIBCPP___CONDITION_VARIABLE_CONDITION_VARIABLE_H
+
+#include <__chrono/steady_clock.h>
+#include <__chrono/system_clock.h>
+#include <__chrono/time_point.h>
+#include <__config>
+#include <__mutex/mutex.h>
+#include <__mutex/unique_lock.h>
+#include <__threading_support>
+#include <__type_traits/enable_if.h>
+#include <__type_traits/is_floating_point.h>
+#include <__utility/move.h>
+#include <ratio>
+#include <system_error>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+#ifndef _LIBCPP_HAS_NO_THREADS
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+// enum class cv_status
+_LIBCPP_DECLARE_STRONG_ENUM(cv_status){no_timeout, timeout};
+_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(cv_status)
+
+class _LIBCPP_TYPE_VIS condition_variable {
+  __libcpp_condvar_t __cv_ = _LIBCPP_CONDVAR_INITIALIZER;
+
+public:
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR condition_variable() _NOEXCEPT = default;
+
+#  ifdef _LIBCPP_HAS_TRIVIAL_CONDVAR_DESTRUCTION
+  ~condition_variable() = default;
+#  else
+  ~condition_variable();
+#  endif
+
+  condition_variable(const condition_variable&)            = delete;
+  condition_variable& operator=(const condition_variable&) = delete;
+
+  void notify_one() _NOEXCEPT;
+  void notify_all() _NOEXCEPT;
+
+  void wait(unique_lock<mutex>& __lk) _NOEXCEPT;
+  template <class _Predicate>
+  _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS void wait(unique_lock<mutex>& __lk, _Predicate __pred);
+
+  template <class _Clock, class _Duration>
+  _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS cv_status
+  wait_until(unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t);
+
+  template <class _Clock, class _Duration, class _Predicate>
+  _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS bool
+  wait_until(unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t, _Predicate __pred);
+
+  template <class _Rep, class _Period>
+  _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS cv_status
+  wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d);
+
+  template <class _Rep, class _Period, class _Predicate>
+  bool _LIBCPP_HIDE_FROM_ABI
+  wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d, _Predicate __pred);
+
+  typedef __libcpp_condvar_t* native_handle_type;
+  _LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() { return &__cv_; }
+
+private:
+  void
+  __do_timed_wait(unique_lock<mutex>& __lk, chrono::time_point<chrono::system_clock, chrono::nanoseconds>) _NOEXCEPT;
+#  if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
+  void
+  __do_timed_wait(unique_lock<mutex>& __lk, chrono::time_point<chrono::steady_clock, chrono::nanoseconds>) _NOEXCEPT;
+#  endif
+  template <class _Clock>
+  void __do_timed_wait(unique_lock<mutex>& __lk, chrono::time_point<_Clock, chrono::nanoseconds>) _NOEXCEPT;
+};
+#endif // !_LIBCPP_HAS_NO_THREADS
+
+template <class _Rep, class _Period>
+inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<is_floating_point<_Rep>::value, chrono::nanoseconds>
+__safe_nanosecond_cast(chrono::duration<_Rep, _Period> __d) {
+  using namespace chrono;
+  using __ratio       = ratio_divide<_Period, nano>;
+  using __ns_rep      = nanoseconds::rep;
+  _Rep __result_float = __d.count() * __ratio::num / __ratio::den;
+
+  _Rep __result_max = numeric_limits<__ns_rep>::max();
+  if (__result_float >= __result_max) {
+    return nanoseconds::max();
+  }
+
+  _Rep __result_min = numeric_limits<__ns_rep>::min();
+  if (__result_float <= __result_min) {
+    return nanoseconds::min();
+  }
+
+  return nanoseconds(static_cast<__ns_rep>(__result_float));
+}
+
+template <class _Rep, class _Period>
+inline _LIBCPP_HIDE_FROM_ABI __enable_if_t<!is_floating_point<_Rep>::value, chrono::nanoseconds>
+__safe_nanosecond_cast(chrono::duration<_Rep, _Period> __d) {
+  using namespace chrono;
+  if (__d.count() == 0) {
+    return nanoseconds(0);
+  }
+
+  using __ratio         = ratio_divide<_Period, nano>;
+  using __ns_rep        = nanoseconds::rep;
+  __ns_rep __result_max = numeric_limits<__ns_rep>::max();
+  if (__d.count() > 0 && __d.count() > __result_max / __ratio::num) {
+    return nanoseconds::max();
+  }
+
+  __ns_rep __result_min = numeric_limits<__ns_rep>::min();
+  if (__d.count() < 0 && __d.count() < __result_min / __ratio::num) {
+    return nanoseconds::min();
+  }
+
+  __ns_rep __result = __d.count() * __ratio::num / __ratio::den;
+  if (__result == 0) {
+    return nanoseconds(1);
+  }
+
+  return nanoseconds(__result);
+}
+
+#ifndef _LIBCPP_HAS_NO_THREADS
+template <class _Predicate>
+void condition_variable::wait(unique_lock<mutex>& __lk, _Predicate __pred) {
+  while (!__pred())
+    wait(__lk);
+}
+
+template <class _Clock, class _Duration>
+cv_status condition_variable::wait_until(unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t) {
+  using namespace chrono;
+  using __clock_tp_ns = time_point<_Clock, nanoseconds>;
+
+  typename _Clock::time_point __now = _Clock::now();
+  if (__t <= __now)
+    return cv_status::timeout;
+
+  __clock_tp_ns __t_ns = __clock_tp_ns(std::__safe_nanosecond_cast(__t.time_since_epoch()));
+
+  __do_timed_wait(__lk, __t_ns);
+  return _Clock::now() < __t ? cv_status::no_timeout : cv_status::timeout;
+}
+
+template <class _Clock, class _Duration, class _Predicate>
+bool condition_variable::wait_until(
+    unique_lock<mutex>& __lk, const chrono::time_point<_Clock, _Duration>& __t, _Predicate __pred) {
+  while (!__pred()) {
+    if (wait_until(__lk, __t) == cv_status::timeout)
+      return __pred();
+  }
+  return true;
+}
+
+template <class _Rep, class _Period>
+cv_status condition_variable::wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d) {
+  using namespace chrono;
+  if (__d <= __d.zero())
+    return cv_status::timeout;
+  using __ns_rep                   = nanoseconds::rep;
+  steady_clock::time_point __c_now = steady_clock::now();
+
+#  if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
+  using __clock_tp_ns     = time_point<steady_clock, nanoseconds>;
+  __ns_rep __now_count_ns = std::__safe_nanosecond_cast(__c_now.time_since_epoch()).count();
+#  else
+  using __clock_tp_ns     = time_point<system_clock, nanoseconds>;
+  __ns_rep __now_count_ns = std::__safe_nanosecond_cast(system_clock::now().time_since_epoch()).count();
+#  endif
+
+  __ns_rep __d_ns_count = std::__safe_nanosecond_cast(__d).count();
+
+  if (__now_count_ns > numeric_limits<__ns_rep>::max() - __d_ns_count) {
+    __do_timed_wait(__lk, __clock_tp_ns::max());
+  } else {
+    __do_timed_wait(__lk, __clock_tp_ns(nanoseconds(__now_count_ns + __d_ns_count)));
+  }
+
+  return steady_clock::now() - __c_now < __d ? cv_status::no_timeout : cv_status::timeout;
+}
+
+template <class _Rep, class _Period, class _Predicate>
+inline bool
+condition_variable::wait_for(unique_lock<mutex>& __lk, const chrono::duration<_Rep, _Period>& __d, _Predicate __pred) {
+  return wait_until(__lk, chrono::steady_clock::now() + __d, std::move(__pred));
+}
+
+#  if defined(_LIBCPP_HAS_COND_CLOCKWAIT)
+inline void condition_variable::__do_timed_wait(
+    unique_lock<mutex>& __lk, chrono::time_point<chrono::steady_clock, chrono::nanoseconds> __tp) _NOEXCEPT {
+  using namespace chrono;
+  if (!__lk.owns_lock())
+    __throw_system_error(EPERM, "condition_variable::timed wait: mutex not locked");
+  nanoseconds __d = __tp.time_since_epoch();
+  timespec __ts;
+  seconds __s                 = duration_cast<seconds>(__d);
+  using __ts_sec              = decltype(__ts.tv_sec);
+  const __ts_sec __ts_sec_max = numeric_limits<__ts_sec>::max();
+  if (__s.count() < __ts_sec_max) {
+    __ts.tv_sec  = static_cast<__ts_sec>(__s.count());
+    __ts.tv_nsec = (__d - __s).count();
+  } else {
+    __ts.tv_sec  = __ts_sec_max;
+    __ts.tv_nsec = giga::num - 1;
+  }
+  int __ec = pthread_cond_clockwait(&__cv_, __lk.mutex()->native_handle(), CLOCK_MONOTONIC, &__ts);
+  if (__ec != 0 && __ec != ETIMEDOUT)
+    __throw_system_error(__ec, "condition_variable timed_wait failed");
+}
+#  endif // _LIBCPP_HAS_COND_CLOCKWAIT
+
+template <class _Clock>
+inline void condition_variable::__do_timed_wait(unique_lock<mutex>& __lk,
+                                                chrono::time_point<_Clock, chrono::nanoseconds> __tp) _NOEXCEPT {
+  wait_for(__lk, __tp - _Clock::now());
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_HAS_NO_THREADS
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___CONDITION_VARIABLE_CONDITION_VARIABLE_H

libcxx/include/__mutex/lock_guard.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_LOCK_GUARD_H
+#define _LIBCPP___MUTEX_LOCK_GUARD_H
+
+#include <__config>
+#include <__mutex/tag_types.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#ifndef _LIBCPP_HAS_NO_THREADS
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Mutex>
+class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable) lock_guard {
+public:
+  typedef _Mutex mutex_type;
+
+private:
+  mutex_type& __m_;
+
+public:
+  _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI explicit lock_guard(mutex_type& __m)
+      _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
+      : __m_(__m) {
+    __m_.lock();
+  }
+
+  _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI lock_guard(mutex_type& __m, adopt_lock_t)
+      _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
+      : __m_(__m) {}
+  _LIBCPP_HIDE_FROM_ABI ~lock_guard() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) { __m_.unlock(); }
+
+private:
+  lock_guard(lock_guard const&)            = delete;
+  lock_guard& operator=(lock_guard const&) = delete;
+};
+_LIBCPP_CTAD_SUPPORTED_FOR_TYPE(lock_guard);
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_HAS_NO_THREADS
+
+#endif // _LIBCPP___MUTEX_LOCK_GUARD_H

libcxx/include/__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)
+  ~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