include/__mutex_base

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// 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_BASE
#define _LIBCPP___MUTEX_BASE

#include <__config>
#include <chrono>
#include <system_error>
#include <__threading_support>

#include <time.h>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif

_LIBCPP_PUSH_MACROS
#include <__undef_macros>


_LIBCPP_BEGIN_NAMESPACE_STD

#ifndef _LIBCPP_HAS_NO_THREADS

#ifndef _LIBCPP_THREAD_SAFETY_ANNOTATION
# ifdef _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
# define _LIBCPP_THREAD_SAFETY_ANNOTATION(x) __attribute__((x))
# else
# define _LIBCPP_THREAD_SAFETY_ANNOTATION(x)
# endif
#endif // _LIBCPP_THREAD_SAFETY_ANNOTATION


class _LIBCPP_TYPE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(capability("mutex")) mutex
{
 __libcpp_mutex_t __m_ = _LIBCPP_MUTEX_INITIALIZER;

public:
 _LIBCPP_INLINE_VISIBILITY
 _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_INLINE_VISIBILITY native_handle_type native_handle() {return &__m_;}
};

static_assert(is_nothrow_default_constructible<mutex>::value,
 "the default constructor for std::mutex must be nothrow");

struct _LIBCPP_TYPE_VIS defer_lock_t {};
struct _LIBCPP_TYPE_VIS try_to_lock_t {};
struct _LIBCPP_TYPE_VIS adopt_lock_t {};

#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)

extern _LIBCPP_EXPORTED_FROM_ABI const defer_lock_t defer_lock;
extern _LIBCPP_EXPORTED_FROM_ABI const try_to_lock_t try_to_lock;
extern _LIBCPP_EXPORTED_FROM_ABI const adopt_lock_t adopt_lock;

#else

/* _LIBCPP_INLINE_VAR */ constexpr defer_lock_t defer_lock = defer_lock_t();
/* _LIBCPP_INLINE_VAR */ constexpr try_to_lock_t try_to_lock = try_to_lock_t();
/* _LIBCPP_INLINE_VAR */ constexpr adopt_lock_t adopt_lock = adopt_lock_t();

#endif

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_INLINE_VISIBILITY
 explicit lock_guard(mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
 : __m_(__m) {__m_.lock();}

 _LIBCPP_NODISCARD_EXT _LIBCPP_INLINE_VISIBILITY
 lock_guard(mutex_type& __m, adopt_lock_t) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
 : __m_(__m) {}
 _LIBCPP_INLINE_VISIBILITY
 ~lock_guard() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) {__m_.unlock();}

private:
 lock_guard(lock_guard const&) _LIBCPP_EQUAL_DELETE;
 lock_guard& operator=(lock_guard const&) _LIBCPP_EQUAL_DELETE;
};

template <class _Mutex>
class _LIBCPP_TEMPLATE_VIS unique_lock
{
public:
 typedef _Mutex mutex_type;

private:
 mutex_type* __m_;
 bool __owns_;

public:
 _LIBCPP_INLINE_VISIBILITY
 unique_lock() _NOEXCEPT : __m_(nullptr), __owns_(false) {}
 _LIBCPP_INLINE_VISIBILITY
 explicit unique_lock(mutex_type& __m)
 : __m_(_VSTD::addressof(__m)), __owns_(true) {__m_->lock();}
 _LIBCPP_INLINE_VISIBILITY
 unique_lock(mutex_type& __m, defer_lock_t) _NOEXCEPT
 : __m_(_VSTD::addressof(__m)), __owns_(false) {}
 _LIBCPP_INLINE_VISIBILITY
 unique_lock(mutex_type& __m, try_to_lock_t)
 : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock()) {}
 _LIBCPP_INLINE_VISIBILITY
 unique_lock(mutex_type& __m, adopt_lock_t)
 : __m_(_VSTD::addressof(__m)), __owns_(true) {}
 template <class _Clock, class _Duration>
 _LIBCPP_INLINE_VISIBILITY
 unique_lock(mutex_type& __m, const chrono::time_point<_Clock, _Duration>& __t)
 : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock_until(__t)) {}
 template <class _Rep, class _Period>
 _LIBCPP_INLINE_VISIBILITY
 unique_lock(mutex_type& __m, const chrono::duration<_Rep, _Period>& __d)
 : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock_for(__d)) {}
 _LIBCPP_INLINE_VISIBILITY
 ~unique_lock()
 {
 if (__owns_)
 __m_->unlock();
 }

private:
 unique_lock(unique_lock const&); // = delete;
 unique_lock& operator=(unique_lock const&); // = delete;

public:
#ifndef _LIBCPP_CXX03_LANG
 _LIBCPP_INLINE_VISIBILITY
 unique_lock(unique_lock&& __u) _NOEXCEPT
 : __m_(__u.__m_), __owns_(__u.__owns_)
 {__u.__m_ = nullptr; __u.__owns_ = false;}
 _LIBCPP_INLINE_VISIBILITY
 unique_lock& operator=(unique_lock&& __u) _NOEXCEPT
 {
 if (__owns_)
 __m_->unlock();
 __m_ = __u.__m_;
 __owns_ = __u.__owns_;
 __u.__m_ = nullptr;
 __u.__owns_ = false;
 return *this;
 }

#endif // _LIBCPP_CXX03_LANG

 void lock();
 bool try_lock();

 template <class _Rep, class _Period>
 bool try_lock_for(const chrono::duration<_Rep, _Period>& __d);
 template <class _Clock, class _Duration>
 bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);

 void unlock();

 _LIBCPP_INLINE_VISIBILITY
 void swap(unique_lock& __u) _NOEXCEPT
 {
 _VSTD::swap(__m_, __u.__m_);
 _VSTD::swap(__owns_, __u.__owns_);
 }
 _LIBCPP_INLINE_VISIBILITY
 mutex_type* release() _NOEXCEPT
 {
 mutex_type* __m = __m_;
 __m_ = nullptr;
 __owns_ = false;
 return __m;
 }

 _LIBCPP_INLINE_VISIBILITY
 bool owns_lock() const _NOEXCEPT {return __owns_;}
 _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_EXPLICIT
 operator bool () const _NOEXCEPT {return __owns_;}
 _LIBCPP_INLINE_VISIBILITY
 mutex_type* mutex() const _NOEXCEPT {return __m_;}
};

template <class _Mutex>
void
unique_lock<_Mutex>::lock()
{
 if (__m_ == nullptr)
 __throw_system_error(EPERM, "unique_lock::lock: references null mutex");
 if (__owns_)
 __throw_system_error(EDEADLK, "unique_lock::lock: already locked");
 __m_->lock();
 __owns_ = true;
}

template <class _Mutex>
bool
unique_lock<_Mutex>::try_lock()
{
 if (__m_ == nullptr)
 __throw_system_error(EPERM, "unique_lock::try_lock: references null mutex");
 if (__owns_)
 __throw_system_error(EDEADLK, "unique_lock::try_lock: already locked");
 __owns_ = __m_->try_lock();
 return __owns_;
}

template <class _Mutex>
template <class _Rep, class _Period>
bool
unique_lock<_Mutex>::try_lock_for(const chrono::duration<_Rep, _Period>& __d)
{
 if (__m_ == nullptr)
 __throw_system_error(EPERM, "unique_lock::try_lock_for: references null mutex");
 if (__owns_)
 __throw_system_error(EDEADLK, "unique_lock::try_lock_for: already locked");
 __owns_ = __m_->try_lock_for(__d);
 return __owns_;
}

template <class _Mutex>
template <class _Clock, class _Duration>
bool
unique_lock<_Mutex>::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
{
 if (__m_ == nullptr)
 __throw_system_error(EPERM, "unique_lock::try_lock_until: references null mutex");
 if (__owns_)
 __throw_system_error(EDEADLK, "unique_lock::try_lock_until: already locked");
 __owns_ = __m_->try_lock_until(__t);
 return __owns_;
}

template <class _Mutex>
void
unique_lock<_Mutex>::unlock()
{
 if (!__owns_)
 __throw_system_error(EPERM, "unique_lock::unlock: not locked");
 __m_->unlock();
 __owns_ = false;
}

template <class _Mutex>
inline _LIBCPP_INLINE_VISIBILITY
void
swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) _NOEXCEPT
 {__x.swap(__y);}

//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_INLINE_VISIBILITY
 _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_INLINE_VISIBILITY
 wait_for(unique_lock<mutex>& __lk,
 const chrono::duration<_Rep, _Period>& __d,
 _Predicate __pred);

 typedef __libcpp_condvar_t* native_handle_type;
 _LIBCPP_INLINE_VISIBILITY 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_INLINE_VISIBILITY
typename enable_if
<
 is_floating_point<_Rep>::value,
 chrono::nanoseconds
>::type
__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_INLINE_VISIBILITY
typename enable_if
<
 !is_floating_point<_Rep>::value,
 chrono::nanoseconds
>::type
__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 = std::numeric_limits<__ns_rep>::max();
 if (__d.count() > 0 && __d.count() > __result_max / __ratio::num) {
 return nanoseconds::max();
 }

 __ns_rep __result_min = std::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(__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 = __safe_nanosecond_cast(__c_now.time_since_epoch()).count();
#else
 using __clock_tp_ns = time_point<system_clock, nanoseconds>;
 __ns_rep __now_count_ns = __safe_nanosecond_cast(system_clock::now().time_since_epoch()).count();
#endif

 __ns_rep __d_ns_count = __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,
 _VSTD::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());
}

#endif // !_LIBCPP_HAS_NO_THREADS

_LIBCPP_END_NAMESPACE_STD

_LIBCPP_POP_MACROS

#endif // _LIBCPP___MUTEX_BASE