// -*- 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_THREAD

#define _LIBCPP_THREAD

/*

    thread synopsis

namespace std

{

class thread

{

public:

    class id;

    typedef pthread_t native_handle_type;

    thread() noexcept;

    template <class F, class ...Args> explicit thread(F&& f, Args&&... args);

    ~thread();

    thread(const thread&) = delete;

    thread(thread&& t) noexcept;

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

    thread& operator=(thread&& t) noexcept;

    void swap(thread& t) noexcept;

    bool joinable() const noexcept;

    void join();

    void detach();

    id get_id() const noexcept;

    native_handle_type native_handle();

    static unsigned hardware_concurrency() noexcept;

};

void swap(thread& x, thread& y) noexcept;

class thread::id

{

public:

    id() noexcept;

};

bool operator==(thread::id x, thread::id y) noexcept;

bool operator!=(thread::id x, thread::id y) noexcept;             // removed in C++20

bool operator< (thread::id x, thread::id y) noexcept;             // removed in C++20

bool operator<=(thread::id x, thread::id y) noexcept;             // removed in C++20

bool operator> (thread::id x, thread::id y) noexcept;             // removed in C++20

bool operator>=(thread::id x, thread::id y) noexcept;             // removed in C++20

strong_ordering operator<=>(thread::id x, thread::id y) noexcept; // C++20

template<class charT, class traits>

basic_ostream<charT, traits>&

operator<<(basic_ostream<charT, traits>& out, thread::id id);

namespace this_thread

{

thread::id get_id() noexcept;

void yield() noexcept;

template <class Clock, class Duration>

void sleep_until(const chrono::time_point<Clock, Duration>& abs_time);

template <class Rep, class Period>

void sleep_for(const chrono::duration<Rep, Period>& rel_time);

}  // this_thread

}  // std

*/

#include <__assert> // all public C++ headers provide the assertion handler

#include <__config>

#include <__functional/hash.h>

#include <__memory/unique_ptr.h>

#include <__mutex_base>

#include <__thread/poll_with_backoff.h>

#include <__thread/timed_backoff_policy.h>

#include <__threading_support>

#include <__utility/forward.h>

#include <cstddef>

#include <iosfwd>

#include <system_error>

#include <tuple>

#include <type_traits>

#include <version>

// standard-mandated includes

// [thread.syn]

#include <compare>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)

#  pragma GCC system_header

#endif

_LIBCPP_PUSH_MACROS

#include <__undef_macros>

#ifdef _LIBCPP_HAS_NO_THREADS

# error "<thread> is not supported since libc++ has been configured without support for threads."

#endif

_LIBCPP_BEGIN_NAMESPACE_STD

template <class _Tp> class __thread_specific_ptr;

class _LIBCPP_TYPE_VIS __thread_struct;

class _LIBCPP_HIDDEN __thread_struct_imp;

class __assoc_sub_state;

_LIBCPP_FUNC_VIS __thread_specific_ptr<__thread_struct>& __thread_local_data();

class _LIBCPP_TYPE_VIS __thread_struct

{

    __thread_struct_imp* __p_;

    __thread_struct(const __thread_struct&);

    __thread_struct& operator=(const __thread_struct&);

public:

    __thread_struct();

    ~__thread_struct();

    void notify_all_at_thread_exit(condition_variable*, mutex*);

    void __make_ready_at_thread_exit(__assoc_sub_state*);

};

template <class _Tp>

class __thread_specific_ptr

{

    __libcpp_tls_key __key_;

     // Only __thread_local_data() may construct a __thread_specific_ptr

     // and only with _Tp == __thread_struct.

    static_assert((is_same<_Tp, __thread_struct>::value), "");

    __thread_specific_ptr();

    friend _LIBCPP_FUNC_VIS __thread_specific_ptr<__thread_struct>& __thread_local_data();

    __thread_specific_ptr(const __thread_specific_ptr&);

    __thread_specific_ptr& operator=(const __thread_specific_ptr&);

    _LIBCPP_HIDDEN static void _LIBCPP_TLS_DESTRUCTOR_CC __at_thread_exit(void*);

public:

    typedef _Tp* pointer;

    ~__thread_specific_ptr();

    _LIBCPP_INLINE_VISIBILITY

    pointer get() const {return static_cast<_Tp*>(__libcpp_tls_get(__key_));}

    _LIBCPP_INLINE_VISIBILITY

    pointer operator*() const {return *get();}

    _LIBCPP_INLINE_VISIBILITY

    pointer operator->() const {return get();}

    void set_pointer(pointer __p);

};

template <class _Tp>

void _LIBCPP_TLS_DESTRUCTOR_CC

__thread_specific_ptr<_Tp>::__at_thread_exit(void* __p)

{

    delete static_cast<pointer>(__p);

}

template <class _Tp>

__thread_specific_ptr<_Tp>::__thread_specific_ptr()

{

  int __ec =

      __libcpp_tls_create(&__key_, &__thread_specific_ptr::__at_thread_exit);

  if (__ec)

    __throw_system_error(__ec, "__thread_specific_ptr construction failed");

}

template <class _Tp>

__thread_specific_ptr<_Tp>::~__thread_specific_ptr()

{

    // __thread_specific_ptr is only created with a static storage duration

    // so this destructor is only invoked during program termination. Invoking

    // pthread_key_delete(__key_) may prevent other threads from deleting their

    // thread local data. For this reason we leak the key.

}

template <class _Tp>

void

__thread_specific_ptr<_Tp>::set_pointer(pointer __p)

{

    _LIBCPP_ASSERT(get() == nullptr,

                   "Attempting to overwrite thread local data");

    std::__libcpp_tls_set(__key_, __p);

}

template<>

struct _LIBCPP_TEMPLATE_VIS hash<__thread_id>

    : public __unary_function<__thread_id, size_t>

{

    _LIBCPP_INLINE_VISIBILITY

    size_t operator()(__thread_id __v) const _NOEXCEPT

    {

        return hash<__libcpp_thread_id>()(__v.__id_);

    }

};

template<class _CharT, class _Traits>

_LIBCPP_INLINE_VISIBILITY

basic_ostream<_CharT, _Traits>&

operator<<(basic_ostream<_CharT, _Traits>& __os, __thread_id __id)

{return __os << __id.__id_;}

class _LIBCPP_TYPE_VIS thread

{

    __libcpp_thread_t __t_;

    thread(const thread&);

    thread& operator=(const thread&);

public:

    typedef __thread_id id;

    typedef __libcpp_thread_t native_handle_type;

    _LIBCPP_INLINE_VISIBILITY

    thread() _NOEXCEPT : __t_(_LIBCPP_NULL_THREAD) {}

#ifndef _LIBCPP_CXX03_LANG

    template <class _Fp, class ..._Args,

              class = __enable_if_t<!is_same<__remove_cvref_t<_Fp>, thread>::value> >

        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS

        explicit thread(_Fp&& __f, _Args&&... __args);

#else  // _LIBCPP_CXX03_LANG

    template <class _Fp>

    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS

    explicit thread(_Fp __f);

#endif

    ~thread();

    _LIBCPP_INLINE_VISIBILITY

    thread(thread&& __t) _NOEXCEPT : __t_(__t.__t_) {

        __t.__t_ = _LIBCPP_NULL_THREAD;

    }

    _LIBCPP_INLINE_VISIBILITY

    thread& operator=(thread&& __t) _NOEXCEPT {

        if (!__libcpp_thread_isnull(&__t_))

            terminate();

        __t_ = __t.__t_;

        __t.__t_ = _LIBCPP_NULL_THREAD;

        return *this;

    }

    _LIBCPP_INLINE_VISIBILITY

    void swap(thread& __t) _NOEXCEPT {_VSTD::swap(__t_, __t.__t_);}

    _LIBCPP_INLINE_VISIBILITY

    bool joinable() const _NOEXCEPT {return !__libcpp_thread_isnull(&__t_);}

    void join();

    void detach();

    _LIBCPP_INLINE_VISIBILITY

    id get_id() const _NOEXCEPT {return __libcpp_thread_get_id(&__t_);}

    _LIBCPP_INLINE_VISIBILITY

    native_handle_type native_handle() _NOEXCEPT {return __t_;}

    static unsigned hardware_concurrency() _NOEXCEPT;

};

#ifndef _LIBCPP_CXX03_LANG

template <class _TSp, class _Fp, class ..._Args, size_t ..._Indices>

inline _LIBCPP_INLINE_VISIBILITY

void

__thread_execute(tuple<_TSp, _Fp, _Args...>& __t, __tuple_indices<_Indices...>)

{

    _VSTD::__invoke(_VSTD::move(_VSTD::get<1>(__t)), _VSTD::move(_VSTD::get<_Indices>(__t))...);

}

template <class _Fp>

_LIBCPP_INLINE_VISIBILITY

void* __thread_proxy(void* __vp)

{

    // _Fp = tuple< unique_ptr<__thread_struct>, Functor, Args...>

    unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp));

    __thread_local_data().set_pointer(_VSTD::get<0>(*__p.get()).release());

    typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 2>::type _Index;

    _VSTD::__thread_execute(*__p.get(), _Index());

    return nullptr;

}

template <class _Fp, class ..._Args,

          class

         >

thread::thread(_Fp&& __f, _Args&&... __args)

{

    typedef unique_ptr<__thread_struct> _TSPtr;

    _TSPtr __tsp(new __thread_struct);

    typedef tuple<_TSPtr, typename decay<_Fp>::type, typename decay<_Args>::type...> _Gp;

    unique_ptr<_Gp> __p(

            new _Gp(_VSTD::move(__tsp),

                    _VSTD::forward<_Fp>(__f),

                    _VSTD::forward<_Args>(__args)...));

    int __ec = _VSTD::__libcpp_thread_create(&__t_, &__thread_proxy<_Gp>, __p.get());

    if (__ec == 0)

        __p.release();

    else

        __throw_system_error(__ec, "thread constructor failed");

}

#else  // _LIBCPP_CXX03_LANG

template <class _Fp>

struct __thread_invoke_pair {

    // This type is used to pass memory for thread local storage and a functor

    // to a newly created thread because std::pair doesn't work with

    // std::unique_ptr in C++03.

    __thread_invoke_pair(_Fp& __f) : __tsp_(new __thread_struct), __fn_(__f) {}

    unique_ptr<__thread_struct> __tsp_;

    _Fp __fn_;

};

template <class _Fp>

_LIBCPP_HIDE_FROM_ABI void* __thread_proxy_cxx03(void* __vp)

{

    unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp));

    __thread_local_data().set_pointer(__p->__tsp_.release());

    (__p->__fn_)();

    return nullptr;

}

template <class _Fp>

thread::thread(_Fp __f)

{

    typedef __thread_invoke_pair<_Fp> _InvokePair;

    typedef unique_ptr<_InvokePair> _PairPtr;

    _PairPtr __pp(new _InvokePair(__f));

    int __ec = _VSTD::__libcpp_thread_create(&__t_, &__thread_proxy_cxx03<_InvokePair>, __pp.get());

    if (__ec == 0)

        __pp.release();

    else

        __throw_system_error(__ec, "thread constructor failed");

}

#endif // _LIBCPP_CXX03_LANG

inline _LIBCPP_INLINE_VISIBILITY

void swap(thread& __x, thread& __y) _NOEXCEPT {__x.swap(__y);}

namespace this_thread

{

_LIBCPP_FUNC_VIS void sleep_for(const chrono::nanoseconds& __ns);

template <class _Rep, class _Period>

_LIBCPP_HIDE_FROM_ABI void

sleep_for(const chrono::duration<_Rep, _Period>& __d)

{

    if (__d > chrono::duration<_Rep, _Period>::zero())

    {

        // The standard guarantees a 64bit signed integer resolution for nanoseconds,

        // so use INT64_MAX / 1e9 as cut-off point. Use a constant to avoid <climits>

        // and issues with long double folding on PowerPC with GCC.

        _LIBCPP_CONSTEXPR chrono::duration<long double> _Max =

            chrono::duration<long double>(9223372036.0L);

        chrono::nanoseconds __ns;

        if (__d < _Max)

        {

            __ns = chrono::duration_cast<chrono::nanoseconds>(__d);

            if (__ns < __d)

                ++__ns;

        }

        else

            __ns = chrono::nanoseconds::max();

        this_thread::sleep_for(__ns);

    }

}

template <class _Clock, class _Duration>

_LIBCPP_HIDE_FROM_ABI void

sleep_until(const chrono::time_point<_Clock, _Duration>& __t)

{

    mutex __mut;

    condition_variable __cv;

    unique_lock<mutex> __lk(__mut);

    while (_Clock::now() < __t)

        __cv.wait_until(__lk, __t);

}

template <class _Duration>

inline _LIBCPP_INLINE_VISIBILITY

void

sleep_until(const chrono::time_point<chrono::steady_clock, _Duration>& __t)

{

    this_thread::sleep_for(__t - chrono::steady_clock::now());

}

inline _LIBCPP_INLINE_VISIBILITY

void yield() _NOEXCEPT {__libcpp_thread_yield();}

} // namespace this_thread

_LIBCPP_END_NAMESPACE_STD

_LIBCPP_POP_MACROS

#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 17

#  include <chrono>

#endif

#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20

#  include <functional>

#endif

#endif // _LIBCPP_THREAD