llvm-project

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// -*- C++ -*-
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//===----------------------------------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#ifndef _LIBCPP_CONDITION_VARIABLE
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#define _LIBCPP_CONDITION_VARIABLE
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/*
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    condition_variable synopsis
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namespace std
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{
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enum class cv_status { no_timeout, timeout };
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class condition_variable
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{
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public:
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    condition_variable();
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    ~condition_variable();
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    condition_variable(const condition_variable&) = delete;
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    condition_variable& operator=(const condition_variable&) = delete;
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    void notify_one() noexcept;
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    void notify_all() noexcept;
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    void wait(unique_lock<mutex>& lock);
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    template <class Predicate>
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        void wait(unique_lock<mutex>& lock, Predicate pred);
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    template <class Clock, class Duration>
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        cv_status
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        wait_until(unique_lock<mutex>& lock,
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                   const chrono::time_point<Clock, Duration>& abs_time);
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    template <class Clock, class Duration, class Predicate>
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        bool
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        wait_until(unique_lock<mutex>& lock,
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                   const chrono::time_point<Clock, Duration>& abs_time,
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                   Predicate pred);
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    template <class Rep, class Period>
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        cv_status
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        wait_for(unique_lock<mutex>& lock,
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                 const chrono::duration<Rep, Period>& rel_time);
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    template <class Rep, class Period, class Predicate>
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        bool
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        wait_for(unique_lock<mutex>& lock,
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                 const chrono::duration<Rep, Period>& rel_time,
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                 Predicate pred);
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    typedef pthread_cond_t* native_handle_type;
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    native_handle_type native_handle();
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};
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void notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk);
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class condition_variable_any
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{
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public:
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    condition_variable_any();
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    ~condition_variable_any();
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    condition_variable_any(const condition_variable_any&) = delete;
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    condition_variable_any& operator=(const condition_variable_any&) = delete;
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    void notify_one() noexcept;
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    void notify_all() noexcept;
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    template <class Lock>
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        void wait(Lock& lock);
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    template <class Lock, class Predicate>
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        void wait(Lock& lock, Predicate pred);
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    template <class Lock, class Clock, class Duration>
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        cv_status
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        wait_until(Lock& lock,
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                   const chrono::time_point<Clock, Duration>& abs_time);
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    template <class Lock, class Clock, class Duration, class Predicate>
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        bool
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        wait_until(Lock& lock,
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                   const chrono::time_point<Clock, Duration>& abs_time,
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                   Predicate pred);
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    template <class Lock, class Rep, class Period>
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        cv_status
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        wait_for(Lock& lock,
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                 const chrono::duration<Rep, Period>& rel_time);
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    template <class Lock, class Rep, class Period, class Predicate>
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        bool
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        wait_for(Lock& lock,
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                 const chrono::duration<Rep, Period>& rel_time,
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                 Predicate pred);
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    // [thread.condvarany.intwait], interruptible waits
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    template <class Lock, class Predicate>
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      bool wait(Lock& lock, stop_token stoken, Predicate pred);                               // since C++20
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    template <class Lock, class Clock, class Duration, class Predicate>
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      bool wait_until(Lock& lock, stop_token stoken,
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                      const chrono::time_point<Clock, Duration>& abs_time, Predicate pred);   // since C++20
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    template <class Lock, class Rep, class Period, class Predicate>
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      bool wait_for(Lock& lock, stop_token stoken,
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                    const chrono::duration<Rep, Period>& rel_time, Predicate pred);           // since C++20
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};
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}  // std
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*/
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#include <__chrono/duration.h>
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#include <__chrono/steady_clock.h>
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#include <__chrono/time_point.h>
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#include <__condition_variable/condition_variable.h>
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#include <__config>
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#include <__memory/shared_ptr.h>
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#include <__mutex/lock_guard.h>
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#include <__mutex/mutex.h>
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#include <__mutex/tag_types.h>
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#include <__mutex/unique_lock.h>
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#include <__stop_token/stop_callback.h>
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#include <__stop_token/stop_token.h>
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#include <__utility/move.h>
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#include <version>
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#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
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#  pragma GCC system_header
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#endif
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_LIBCPP_PUSH_MACROS
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#include <__undef_macros>
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#ifndef _LIBCPP_HAS_NO_THREADS
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_LIBCPP_BEGIN_NAMESPACE_STD
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class _LIBCPP_EXPORTED_FROM_ABI condition_variable_any {
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  condition_variable __cv_;
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  shared_ptr<mutex> __mut_;
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public:
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  _LIBCPP_HIDE_FROM_ABI condition_variable_any();
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  _LIBCPP_HIDE_FROM_ABI void notify_one() _NOEXCEPT;
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  _LIBCPP_HIDE_FROM_ABI void notify_all() _NOEXCEPT;
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  template <class _Lock>
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  _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS void wait(_Lock& __lock);
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  template <class _Lock, class _Predicate>
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  _LIBCPP_HIDE_FROM_ABI void wait(_Lock& __lock, _Predicate __pred);
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  template <class _Lock, class _Clock, class _Duration>
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  _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS cv_status
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  wait_until(_Lock& __lock, const chrono::time_point<_Clock, _Duration>& __t);
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  template <class _Lock, class _Clock, class _Duration, class _Predicate>
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  bool _LIBCPP_HIDE_FROM_ABI
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  wait_until(_Lock& __lock, const chrono::time_point<_Clock, _Duration>& __t, _Predicate __pred);
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  template <class _Lock, class _Rep, class _Period>
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  cv_status _LIBCPP_HIDE_FROM_ABI wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __d);
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  template <class _Lock, class _Rep, class _Period, class _Predicate>
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  bool _LIBCPP_HIDE_FROM_ABI wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __d, _Predicate __pred);
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#  if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
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  template <class _Lock, class _Predicate>
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  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool wait(_Lock& __lock, stop_token __stoken, _Predicate __pred);
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  template <class _Lock, class _Clock, class _Duration, class _Predicate>
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  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool wait_until(
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      _Lock& __lock, stop_token __stoken, const chrono::time_point<_Clock, _Duration>& __abs_time, _Predicate __pred);
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  template <class _Lock, class _Rep, class _Period, class _Predicate>
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  _LIBCPP_AVAILABILITY_SYNC _LIBCPP_HIDE_FROM_ABI bool
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  wait_for(_Lock& __lock, stop_token __stoken, const chrono::duration<_Rep, _Period>& __rel_time, _Predicate __pred);
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#  endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
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};
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inline condition_variable_any::condition_variable_any() : __mut_(make_shared<mutex>()) {}
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inline void condition_variable_any::notify_one() _NOEXCEPT {
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  { lock_guard<mutex> __lx(*__mut_); }
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  __cv_.notify_one();
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}
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inline void condition_variable_any::notify_all() _NOEXCEPT {
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  { lock_guard<mutex> __lx(*__mut_); }
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  __cv_.notify_all();
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}
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template <class _Lock>
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struct __unlock_guard {
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  _Lock& __lock_;
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  _LIBCPP_HIDE_FROM_ABI __unlock_guard(_Lock& __lock) : __lock_(__lock) { __lock_.unlock(); }
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  _LIBCPP_HIDE_FROM_ABI ~__unlock_guard() _NOEXCEPT // turns exception to std::terminate
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  {
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    __lock_.lock();
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  }
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  __unlock_guard(const __unlock_guard&)            = delete;
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  __unlock_guard& operator=(const __unlock_guard&) = delete;
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};
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template <class _Lock>
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void condition_variable_any::wait(_Lock& __lock) {
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  shared_ptr<mutex> __mut = __mut_;
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  unique_lock<mutex> __lk(*__mut);
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  __unlock_guard<_Lock> __unlock(__lock);
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  lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock_t());
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  __cv_.wait(__lk);
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} // __mut_.unlock(), __lock.lock()
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template <class _Lock, class _Predicate>
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inline void condition_variable_any::wait(_Lock& __lock, _Predicate __pred) {
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  while (!__pred())
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    wait(__lock);
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}
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template <class _Lock, class _Clock, class _Duration>
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cv_status condition_variable_any::wait_until(_Lock& __lock, const chrono::time_point<_Clock, _Duration>& __t) {
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  shared_ptr<mutex> __mut = __mut_;
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  unique_lock<mutex> __lk(*__mut);
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  __unlock_guard<_Lock> __unlock(__lock);
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  lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock_t());
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  return __cv_.wait_until(__lk, __t);
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} // __mut_.unlock(), __lock.lock()
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template <class _Lock, class _Clock, class _Duration, class _Predicate>
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inline bool
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condition_variable_any::wait_until(_Lock& __lock, const chrono::time_point<_Clock, _Duration>& __t, _Predicate __pred) {
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  while (!__pred())
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    if (wait_until(__lock, __t) == cv_status::timeout)
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      return __pred();
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  return true;
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}
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template <class _Lock, class _Rep, class _Period>
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inline cv_status condition_variable_any::wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __d) {
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  return wait_until(__lock, chrono::steady_clock::now() + __d);
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}
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template <class _Lock, class _Rep, class _Period, class _Predicate>
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inline bool
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condition_variable_any::wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __d, _Predicate __pred) {
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  return wait_until(__lock, chrono::steady_clock::now() + __d, std::move(__pred));
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}
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#  if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
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template <class _Lock, class _Predicate>
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bool condition_variable_any::wait(_Lock& __user_lock, stop_token __stoken, _Predicate __pred) {
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  if (__stoken.stop_requested())
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    return __pred();
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  // Per https://eel.is/c++draft/thread.condition.condvarany#general-note-2,
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  // we do need to take a copy of the shared pointer __mut_
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  // This ensures that a thread can call the destructor immediately after calling
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  // notify_all, without waiting all the wait calls.
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  // A thread can also safely call the destructor immediately after calling
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  // request_stop, as the call to request_stop would evaluate the callback,
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  // which accesses the internal condition variable, immediately on the same thread.
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  // In this situation, it is OK even without copying a shared ownership the internal
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  // condition variable. However, this needs the evaluation of stop_callback to
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  // happen-before the destruction.
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  // The spec only says "Only the notification to unblock the wait needs to happen
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  // before destruction". To make this work, we need to copy the shared ownership of
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  // the internal condition variable inside this function, which is not possible
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  // with the current ABI.
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  shared_ptr<mutex> __mut = __mut_;
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  stop_callback __cb(__stoken, [this] { notify_all(); });
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  while (true) {
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    if (__pred())
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      return true;
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    // We need to take the internal lock before checking stop_requested,
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    // so that the notification cannot come in between the stop_requested
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    // check and entering the wait.
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    // Note that the stop_callback takes the same internal lock before notifying
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    unique_lock<mutex> __internal_lock(*__mut);
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    if (__stoken.stop_requested())
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      break;
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    __unlock_guard<_Lock> __unlock(__user_lock);
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    unique_lock<mutex> __internal_lock2(
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        std::move(__internal_lock)); // switch unlock order between __internal_lock and __user_lock
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    __cv_.wait(__internal_lock2);
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  } // __internal_lock2.unlock(), __user_lock.lock()
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  return __pred();
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}
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template <class _Lock, class _Clock, class _Duration, class _Predicate>
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bool condition_variable_any::wait_until(
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    _Lock& __user_lock,
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    stop_token __stoken,
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    const chrono::time_point<_Clock, _Duration>& __abs_time,
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    _Predicate __pred) {
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  if (__stoken.stop_requested())
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    return __pred();
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  shared_ptr<mutex> __mut = __mut_;
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  stop_callback __cb(__stoken, [this] { notify_all(); });
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  while (true) {
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    if (__pred())
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      return true;
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    unique_lock<mutex> __internal_lock(*__mut);
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    if (__stoken.stop_requested())
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      break;
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    __unlock_guard<_Lock> __unlock(__user_lock);
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    unique_lock<mutex> __internal_lock2(
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        std::move(__internal_lock)); // switch unlock order between __internal_lock and __user_lock
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    if (__cv_.wait_until(__internal_lock2, __abs_time) == cv_status::timeout)
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      break;
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  } // __internal_lock2.unlock(), __user_lock.lock()
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  return __pred();
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}
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template <class _Lock, class _Rep, class _Period, class _Predicate>
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bool condition_variable_any::wait_for(
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    _Lock& __lock, stop_token __stoken, const chrono::duration<_Rep, _Period>& __rel_time, _Predicate __pred) {
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  return wait_until(__lock, std::move(__stoken), chrono::steady_clock::now() + __rel_time, std::move(__pred));
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}
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#  endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_STOP_TOKEN)
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_LIBCPP_EXPORTED_FROM_ABI void notify_all_at_thread_exit(condition_variable&, unique_lock<mutex>);
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_LIBCPP_END_NAMESPACE_STD
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#endif // !_LIBCPP_HAS_NO_THREADS
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_LIBCPP_POP_MACROS
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#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
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#  include <atomic>
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#  include <concepts>
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#  include <cstdint>
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#  include <cstdlib>
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#  include <cstring>
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#  include <initializer_list>
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#  include <iosfwd>
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#  include <new>
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#  include <stdexcept>
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#  include <system_error>
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#  include <type_traits>
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#  include <typeinfo>
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#endif
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#endif // _LIBCPP_CONDITION_VARIABLE
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