xref: /freebsd/contrib/llvm-project/libcxx/include/condition_variable (revision 5f757f3ff9144b609b3c433dfd370cc6bdc191ad)

// -*- 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_CONDITION_VARIABLE
#define _LIBCPP_CONDITION_VARIABLE

/*
    condition_variable synopsis

namespace std
{

enum class cv_status { no_timeout, timeout };

class condition_variable
{
public:
    condition_variable();
    ~condition_variable();

    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>& lock);
    template <class Predicate>
        void wait(unique_lock<mutex>& lock, Predicate pred);

    template <class Clock, class Duration>
        cv_status
        wait_until(unique_lock<mutex>& lock,
                   const chrono::time_point<Clock, Duration>& abs_time);

    template <class Clock, class Duration, class Predicate>
        bool
        wait_until(unique_lock<mutex>& lock,
                   const chrono::time_point<Clock, Duration>& abs_time,
                   Predicate pred);

    template <class Rep, class Period>
        cv_status
        wait_for(unique_lock<mutex>& lock,
                 const chrono::duration<Rep, Period>& rel_time);

    template <class Rep, class Period, class Predicate>
        bool
        wait_for(unique_lock<mutex>& lock,
                 const chrono::duration<Rep, Period>& rel_time,
                 Predicate pred);

    typedef pthread_cond_t* native_handle_type;
    native_handle_type native_handle();
};

void notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk);

class condition_variable_any
{
public:
    condition_variable_any();
    ~condition_variable_any();

    condition_variable_any(const condition_variable_any&) = delete;
    condition_variable_any& operator=(const condition_variable_any&) = delete;

    void notify_one() noexcept;
    void notify_all() noexcept;

    template <class Lock>
        void wait(Lock& lock);
    template <class Lock, class Predicate>
        void wait(Lock& lock, Predicate pred);

    template <class Lock, class Clock, class Duration>
        cv_status
        wait_until(Lock& lock,
                   const chrono::time_point<Clock, Duration>& abs_time);

    template <class Lock, class Clock, class Duration, class Predicate>
        bool
        wait_until(Lock& lock,
                   const chrono::time_point<Clock, Duration>& abs_time,
                   Predicate pred);

    template <class Lock, class Rep, class Period>
        cv_status
        wait_for(Lock& lock,
                 const chrono::duration<Rep, Period>& rel_time);

    template <class Lock, class Rep, class Period, class Predicate>
        bool
        wait_for(Lock& lock,
                 const chrono::duration<Rep, Period>& rel_time,
                 Predicate pred);

    // [thread.condvarany.intwait], interruptible waits
    template <class Lock, class Predicate>
      bool wait(Lock& lock, stop_token stoken, Predicate pred);                               // since C++20

    template <class Lock, class Clock, class Duration, class Predicate>
      bool wait_until(Lock& lock, stop_token stoken,
                      const chrono::time_point<Clock, Duration>& abs_time, Predicate pred);   // since C++20

    template <class Lock, class Rep, class Period, class Predicate>
      bool wait_for(Lock& lock, stop_token stoken,
                    const chrono::duration<Rep, Period>& rel_time, Predicate pred);           // since C++20
};

}  // std

*/

#include <__assert> // all public C++ headers provide the assertion handler
#include <__availability>
#include <__chrono/duration.h>
#include <__chrono/steady_clock.h>
#include <__chrono/time_point.h>
#include <__condition_variable/condition_variable.h>
#include <__config>
#include <__memory/shared_ptr.h>
#include <__memory/unique_ptr.h>
#include <__mutex/lock_guard.h>
#include <__mutex/mutex.h>
#include <__mutex/tag_types.h>
#include <__mutex/unique_lock.h>
#include <__stop_token/stop_token.h>
#include <__utility/move.h>
#include <version>

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

#ifndef _LIBCPP_HAS_NO_THREADS

_LIBCPP_BEGIN_NAMESPACE_STD

class _LIBCPP_EXPORTED_FROM_ABI condition_variable_any
{
    condition_variable __cv_;
    shared_ptr<mutex>  __mut_;
public:
    _LIBCPP_HIDE_FROM_ABI
    condition_variable_any();

    _LIBCPP_HIDE_FROM_ABI
    void notify_one() _NOEXCEPT;
    _LIBCPP_HIDE_FROM_ABI
    void notify_all() _NOEXCEPT;

    template <class _Lock>
        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
        void wait(_Lock& __lock);
    template <class _Lock, class _Predicate>
        _LIBCPP_HIDE_FROM_ABI
        void wait(_Lock& __lock, _Predicate __pred);

    template <class _Lock, class _Clock, class _Duration>
        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
        cv_status
        wait_until(_Lock& __lock,
                   const chrono::time_point<_Clock, _Duration>& __t);

    template <class _Lock, class _Clock, class _Duration, class _Predicate>
        bool
        _LIBCPP_HIDE_FROM_ABI
        wait_until(_Lock& __lock,
                   const chrono::time_point<_Clock, _Duration>& __t,
                   _Predicate __pred);

    template <class _Lock, class _Rep, class _Period>
        cv_status
        _LIBCPP_HIDE_FROM_ABI
        wait_for(_Lock& __lock,
                 const chrono::duration<_Rep, _Period>& __d);

    template <class _Lock, class _Rep, class _Period, class _Predicate>
        bool
        _LIBCPP_HIDE_FROM_ABI
        wait_for(_Lock& __lock,
                 const chrono::duration<_Rep, _Period>& __d,
                 _Predicate __pred);

#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)

    template <class _Lock, class _Predicate>
    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool wait(_Lock& __lock, stop_token __stoken, _Predicate __pred);

    template <class _Lock, class _Clock, class _Duration, class _Predicate>
    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool wait_until(_Lock& __lock, stop_token __stoken,
                const chrono::time_point<_Clock, _Duration>& __abs_time, _Predicate __pred);

    template <class _Lock, class _Rep, class _Period, class _Predicate>
    _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool wait_for(_Lock& __lock, stop_token __stoken,
                const chrono::duration<_Rep, _Period>& __rel_time, _Predicate __pred);

#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
};

inline
condition_variable_any::condition_variable_any()
    : __mut_(make_shared<mutex>()) {}

inline
void
condition_variable_any::notify_one() _NOEXCEPT
{
    {lock_guard<mutex> __lx(*__mut_);}
    __cv_.notify_one();
}

inline
void
condition_variable_any::notify_all() _NOEXCEPT
{
    {lock_guard<mutex> __lx(*__mut_);}
    __cv_.notify_all();
}

struct __lock_external
{
    template <class _Lock>
    _LIBCPP_HIDE_FROM_ABI void operator()(_Lock* __m) {__m->lock();}
};

template <class _Lock>
void
condition_variable_any::wait(_Lock& __lock)
{
    shared_ptr<mutex> __mut = __mut_;
    unique_lock<mutex> __lk(*__mut);
    __lock.unlock();
    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock_t());
    __cv_.wait(__lk);
}  // __mut_.unlock(), __lock.lock()

template <class _Lock, class _Predicate>
inline
void
condition_variable_any::wait(_Lock& __lock, _Predicate __pred)
{
    while (!__pred())
        wait(__lock);
}

template <class _Lock, class _Clock, class _Duration>
cv_status
condition_variable_any::wait_until(_Lock& __lock,
                                   const chrono::time_point<_Clock, _Duration>& __t)
{
    shared_ptr<mutex> __mut = __mut_;
    unique_lock<mutex> __lk(*__mut);
    __lock.unlock();
    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock_t());
    return __cv_.wait_until(__lk, __t);
}  // __mut_.unlock(), __lock.lock()

template <class _Lock, class _Clock, class _Duration, class _Predicate>
inline
bool
condition_variable_any::wait_until(_Lock& __lock,
                                   const chrono::time_point<_Clock, _Duration>& __t,
                                   _Predicate __pred)
{
    while (!__pred())
        if (wait_until(__lock, __t) == cv_status::timeout)
            return __pred();
    return true;
}

template <class _Lock, class _Rep, class _Period>
inline
cv_status
condition_variable_any::wait_for(_Lock& __lock,
                                 const chrono::duration<_Rep, _Period>& __d)
{
    return wait_until(__lock, chrono::steady_clock::now() + __d);
}

template <class _Lock, class _Rep, class _Period, class _Predicate>
inline
bool
condition_variable_any::wait_for(_Lock& __lock,
                                 const chrono::duration<_Rep, _Period>& __d,
                                 _Predicate __pred)
{
    return wait_until(__lock, chrono::steady_clock::now() + __d,
                      std::move(__pred));
}

#if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)

template <class _Lock, class _Predicate>
bool condition_variable_any::wait(_Lock& __lock, stop_token __stoken, _Predicate __pred) {
    while (!__stoken.stop_requested()) {
        if (__pred())
            return true;
        wait(__lock);
    }
    return __pred();
}

template <class _Lock, class _Clock, class _Duration, class _Predicate>
bool condition_variable_any::wait_until(
    _Lock& __lock, stop_token __stoken, const chrono::time_point<_Clock, _Duration>& __abs_time, _Predicate __pred) {
    while (!__stoken.stop_requested()) {
        if (__pred())
            return true;
        if (wait_until(__lock, __abs_time) == cv_status::timeout)
            return __pred();
    }
    return __pred();
}

template <class _Lock, class _Rep, class _Period, class _Predicate>
bool condition_variable_any::wait_for(
    _Lock& __lock, stop_token __stoken, const chrono::duration<_Rep, _Period>& __rel_time, _Predicate __pred) {
    return wait_until(__lock, std::move(__stoken), chrono::steady_clock::now() + __rel_time, std::move(__pred));
}

#endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)

_LIBCPP_EXPORTED_FROM_ABI void notify_all_at_thread_exit(condition_variable&, unique_lock<mutex>);

_LIBCPP_END_NAMESPACE_STD

#endif // !_LIBCPP_HAS_NO_THREADS

#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
#  include <atomic>
#  include <concepts>
#  include <cstdint>
#  include <cstdlib>
#  include <cstring>
#  include <initializer_list>
#  include <iosfwd>
#  include <new>
#  include <stdexcept>
#  include <system_error>
#  include <type_traits>
#  include <typeinfo>
#endif

#endif // _LIBCPP_CONDITION_VARIABLE