llvm-project/libcxx/include/thread

491 lines
13 KiB
C++

// -*- C++ -*-
//===--------------------------- thread -----------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP_THREAD
#define _LIBCPP_THREAD
/*
thread synopsis
#define __STDCPP_THREADS__ __cplusplus
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;
bool operator< (thread::id x, thread::id y) noexcept;
bool operator<=(thread::id x, thread::id y) noexcept;
bool operator> (thread::id x, thread::id y) noexcept;
bool operator>=(thread::id x, thread::id y) noexcept;
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 <__config>
#include <iosfwd>
#include <__functional_base>
#include <type_traits>
#include <cstddef>
#include <functional>
#include <memory>
#include <system_error>
#include <chrono>
#include <__mutex_base>
#ifndef _LIBCPP_HAS_NO_VARIADICS
#include <tuple>
#endif
#include <__threading_support>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif
#define __STDCPP_THREADS__ __cplusplus
#ifdef _LIBCPP_HAS_NO_THREADS
#error <thread> is not supported on this single threaded system
#else // !_LIBCPP_HAS_NO_THREADS
_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_tl_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&);
static void __at_thread_exit(void*);
public:
typedef _Tp* pointer;
~__thread_specific_ptr();
_LIBCPP_INLINE_VISIBILITY
pointer get() const {return static_cast<_Tp*>(__libcpp_tl_get(__key_));}
_LIBCPP_INLINE_VISIBILITY
pointer operator*() const {return *get();}
_LIBCPP_INLINE_VISIBILITY
pointer operator->() const {return get();}
pointer release();
void reset(pointer __p = nullptr);
};
template <class _Tp>
void
__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_tl_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>
typename __thread_specific_ptr<_Tp>::pointer
__thread_specific_ptr<_Tp>::release()
{
pointer __p = get();
__libcpp_tl_set(__key_, nullptr);
return __p;
}
template <class _Tp>
void
__thread_specific_ptr<_Tp>::reset(pointer __p)
{
pointer __p_old = get();
__libcpp_tl_set(__key_, __p);
delete __p_old;
}
class _LIBCPP_TYPE_VIS thread;
class _LIBCPP_TYPE_VIS __thread_id;
namespace this_thread
{
_LIBCPP_INLINE_VISIBILITY __thread_id get_id() _NOEXCEPT;
} // this_thread
template<> struct hash<__thread_id>;
class _LIBCPP_TYPE_VIS_ONLY __thread_id
{
// FIXME: pthread_t is a pointer on Darwin but a long on Linux.
// NULL is the no-thread value on Darwin. Someone needs to check
// on other platforms. We assume 0 works everywhere for now.
__libcpp_thread_id __id_;
public:
_LIBCPP_INLINE_VISIBILITY
__thread_id() _NOEXCEPT : __id_(0) {}
friend _LIBCPP_INLINE_VISIBILITY
bool operator==(__thread_id __x, __thread_id __y) _NOEXCEPT
{return __libcpp_thread_id_equal(__x.__id_, __y.__id_);}
friend _LIBCPP_INLINE_VISIBILITY
bool operator!=(__thread_id __x, __thread_id __y) _NOEXCEPT
{return !(__x == __y);}
friend _LIBCPP_INLINE_VISIBILITY
bool operator< (__thread_id __x, __thread_id __y) _NOEXCEPT
{return __libcpp_thread_id_less(__x.__id_, __y.__id_);}
friend _LIBCPP_INLINE_VISIBILITY
bool operator<=(__thread_id __x, __thread_id __y) _NOEXCEPT
{return !(__y < __x);}
friend _LIBCPP_INLINE_VISIBILITY
bool operator> (__thread_id __x, __thread_id __y) _NOEXCEPT
{return __y < __x ;}
friend _LIBCPP_INLINE_VISIBILITY
bool operator>=(__thread_id __x, __thread_id __y) _NOEXCEPT
{return !(__x < __y);}
template<class _CharT, class _Traits>
friend
_LIBCPP_INLINE_VISIBILITY
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __os, __thread_id __id)
{return __os << __id.__id_;}
private:
_LIBCPP_INLINE_VISIBILITY
__thread_id(__libcpp_thread_id __id) : __id_(__id) {}
friend __thread_id this_thread::get_id() _NOEXCEPT;
friend class _LIBCPP_TYPE_VIS thread;
friend struct _LIBCPP_TYPE_VIS_ONLY hash<__thread_id>;
};
template<>
struct _LIBCPP_TYPE_VIS_ONLY hash<__thread_id>
: public unary_function<__thread_id, size_t>
{
_LIBCPP_INLINE_VISIBILITY
size_t operator()(__thread_id __v) const
{
return hash<__libcpp_thread_id>()(__v.__id_);
}
};
namespace this_thread
{
inline _LIBCPP_INLINE_VISIBILITY
__thread_id
get_id() _NOEXCEPT
{
return __libcpp_thread_get_current_id();
}
} // this_thread
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_(0) {}
#ifndef _LIBCPP_HAS_NO_VARIADICS
template <class _Fp, class ..._Args,
class = typename enable_if
<
!is_same<typename decay<_Fp>::type, thread>::value
>::type
>
explicit thread(_Fp&& __f, _Args&&... __args);
#else // _LIBCPP_HAS_NO_VARIADICS
template <class _Fp> explicit thread(_Fp __f);
#endif
~thread();
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
_LIBCPP_INLINE_VISIBILITY
thread(thread&& __t) _NOEXCEPT : __t_(__t.__t_) {__t.__t_ = 0;}
_LIBCPP_INLINE_VISIBILITY
thread& operator=(thread&& __t) _NOEXCEPT;
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
_LIBCPP_INLINE_VISIBILITY
void swap(thread& __t) _NOEXCEPT {_VSTD::swap(__t_, __t.__t_);}
_LIBCPP_INLINE_VISIBILITY
bool joinable() const _NOEXCEPT {return __t_ != 0;}
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_HAS_NO_VARIADICS
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...>)
{
__invoke(_VSTD::move(_VSTD::get<1>(__t)), _VSTD::move(_VSTD::get<_Indices>(__t))...);
}
template <class _Fp>
void* __thread_proxy(void* __vp)
{
// _Fp = std::tuple< unique_ptr<__thread_struct>, Functor, Args...>
std::unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp));
__thread_local_data().reset(_VSTD::get<0>(*__p).release());
typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 2>::type _Index;
__thread_execute(*__p, _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;
_VSTD::unique_ptr<_Gp> __p(
new _Gp(std::move(__tsp),
__decay_copy(_VSTD::forward<_Fp>(__f)),
__decay_copy(_VSTD::forward<_Args>(__args))...));
int __ec = __libcpp_thread_create(&__t_, &__thread_proxy<_Gp>, __p.get());
if (__ec == 0)
__p.release();
else
__throw_system_error(__ec, "thread constructor failed");
}
#else // _LIBCPP_HAS_NO_VARIADICS
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>
void* __thread_proxy_cxx03(void* __vp)
{
std::unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp));
__thread_local_data().reset(__p->__tsp_.release());
(__p->__fn_)();
return nullptr;
}
template <class _Fp>
thread::thread(_Fp __f)
{
typedef __thread_invoke_pair<_Fp> _InvokePair;
typedef std::unique_ptr<_InvokePair> _PairPtr;
_PairPtr __pp(new _InvokePair(__f));
int __ec = __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_HAS_NO_VARIADICS
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
inline
thread&
thread::operator=(thread&& __t) _NOEXCEPT
{
if (__t_ != 0)
terminate();
__t_ = __t.__t_;
__t.__t_ = 0;
return *this;
}
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
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>
void
sleep_for(const chrono::duration<_Rep, _Period>& __d)
{
using namespace chrono;
if (__d > duration<_Rep, _Period>::zero())
{
_LIBCPP_CONSTEXPR duration<long double> _Max = nanoseconds::max();
nanoseconds __ns;
if (__d < _Max)
{
__ns = duration_cast<nanoseconds>(__d);
if (__ns < __d)
++__ns;
}
else
__ns = nanoseconds::max();
sleep_for(__ns);
}
}
template <class _Clock, class _Duration>
void
sleep_until(const chrono::time_point<_Clock, _Duration>& __t)
{
using namespace chrono;
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)
{
using namespace chrono;
sleep_for(__t - steady_clock::now());
}
inline _LIBCPP_INLINE_VISIBILITY
void yield() _NOEXCEPT {__libcpp_thread_yield();}
} // this_thread
_LIBCPP_END_NAMESPACE_STD
#endif // !_LIBCPP_HAS_NO_THREADS
#endif // _LIBCPP_THREAD