3// Copyright (C) 2008-2016 Free Software Foundation, Inc.
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
25/** @file include/thread
26 * This is a Standard C++ Library header.
29#ifndef _GLIBCXX_THREAD
30#define _GLIBCXX_THREAD 1
32#pragma GCC system_header
34#if __cplusplus < 201103L
35# include <bits/c++0x_warning.h>
42#include <bits/functexcept.h>
43#include <bits/functional_hash.h>
46#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
48namespace std _GLIBCXX_VISIBILITY(default)
50_GLIBCXX_BEGIN_NAMESPACE_VERSION
53 * @defgroup threads Threads
54 * @ingroup concurrency
56 * Classes for thread support.
64 // Abstract base class for types that wrap arbitrary functors to be
65 // invoked in the new thread of execution.
69 virtual void _M_run() = 0;
71 using _State_ptr = unique_ptr<_State>;
73 typedef __gthread_t native_handle_type;
78 native_handle_type _M_thread;
81 id() noexcept : _M_thread() { }
84 id(native_handle_type __id) : _M_thread(__id) { }
88 friend class hash<thread::id>;
91 operator==(thread::id __x, thread::id __y) noexcept
93 // pthread_equal is undefined if either thread ID is not valid, so we
94 // can't safely use __gthread_equal on default-constructed values (nor
95 // the non-zero value returned by this_thread::get_id() for
96 // single-threaded programs using GNU libc). Assume EqualityComparable.
97 return __x._M_thread == __y._M_thread;
101 operator<(thread::id __x, thread::id __y) noexcept
103 // Pthreads doesn't define any way to do this, so we just have to
104 // assume native_handle_type is LessThanComparable.
105 return __x._M_thread < __y._M_thread;
108 template<class _CharT, class _Traits>
109 friend basic_ostream<_CharT, _Traits>&
110 operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id);
117 thread() noexcept = default;
118 // _GLIBCXX_RESOLVE_LIB_DEFECTS
119 // 2097. packaged_task constructors should be constrained
120 thread(thread&) = delete;
121 thread(const thread&) = delete;
122 thread(const thread&&) = delete;
124 thread(thread&& __t) noexcept
127 template<typename _Callable, typename... _Args>
129 thread(_Callable&& __f, _Args&&... __args)
131#ifdef GTHR_ACTIVE_PROXY
132 // Create a reference to pthread_create, not just the gthr weak symbol.
133 auto __depend = reinterpret_cast<void(*)()>(&pthread_create);
135 auto __depend = nullptr;
137 _M_start_thread(_S_make_state(
138 std::__bind_simple(std::forward<_Callable>(__f),
139 std::forward<_Args>(__args)...)),
149 thread& operator=(const thread&) = delete;
151 thread& operator=(thread&& __t) noexcept
160 swap(thread& __t) noexcept
161 { std::swap(_M_id, __t._M_id); }
164 joinable() const noexcept
165 { return !(_M_id == id()); }
174 get_id() const noexcept
177 /** @pre thread is joinable
181 { return _M_id._M_thread; }
183 // Returns a value that hints at the number of hardware thread contexts.
185 hardware_concurrency() noexcept;
188 template<typename _Callable>
189 struct _State_impl : public _State
193 _State_impl(_Callable&& __f) : _M_func(std::forward<_Callable>(__f))
197 _M_run() { _M_func(); }
201 _M_start_thread(_State_ptr, void (*)());
203 template<typename _Callable>
205 _S_make_state(_Callable&& __f)
207 using _Impl = _State_impl<_Callable>;
208 return _State_ptr{new _Impl{std::forward<_Callable>(__f)}};
210#if _GLIBCXX_THREAD_ABI_COMPAT
213 typedef shared_ptr<_Impl_base> __shared_base_type;
216 __shared_base_type _M_this_ptr;
217 virtual ~_Impl_base() = default;
218 virtual void _M_run() = 0;
223 _M_start_thread(__shared_base_type, void (*)());
226 _M_start_thread(__shared_base_type);
231 swap(thread& __x, thread& __y) noexcept
235 operator!=(thread::id __x, thread::id __y) noexcept
236 { return !(__x == __y); }
239 operator<=(thread::id __x, thread::id __y) noexcept
240 { return !(__y < __x); }
243 operator>(thread::id __x, thread::id __y) noexcept
244 { return __y < __x; }
247 operator>=(thread::id __x, thread::id __y) noexcept
248 { return !(__x < __y); }
251 /// std::hash specialization for thread::id.
253 struct hash<thread::id>
254 : public __hash_base<size_t, thread::id>
257 operator()(const thread::id& __id) const noexcept
258 { return std::_Hash_impl::hash(__id._M_thread); }
261 template<class _CharT, class _Traits>
262 inline basic_ostream<_CharT, _Traits>&
263 operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
265 if (__id == thread::id())
266 return __out << "thread::id of a non-executing thread";
268 return __out << __id._M_thread;
271_GLIBCXX_END_NAMESPACE_VERSION
273 /** @namespace std::this_thread
274 * @brief ISO C++ 2011 entities sub-namespace for thread.
275 * 30.3.2 Namespace this_thread.
277 namespace this_thread
279 _GLIBCXX_BEGIN_NAMESPACE_VERSION
286 // For the GNU C library pthread_self() is usable without linking to
287 // libpthread.so but returns 0, so we cannot use it in single-threaded
288 // programs, because this_thread::get_id() != thread::id{} must be true.
289 // We know that pthread_t is an integral type in the GNU C library.
290 if (!__gthread_active_p())
291 return thread::id(1);
293 return thread::id(__gthread_self());
300#ifdef _GLIBCXX_USE_SCHED_YIELD
306 __sleep_for(chrono::seconds, chrono::nanoseconds);
309 template<typename _Rep, typename _Period>
311 sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
313 if (__rtime <= __rtime.zero())
315 auto __s = chrono::duration_cast<chrono::seconds>(__rtime);
316 auto __ns = chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
317#ifdef _GLIBCXX_USE_NANOSLEEP
318 __gthread_time_t __ts =
320 static_cast<std::time_t>(__s.count()),
321 static_cast<long>(__ns.count())
323 while (::nanosleep(&__ts, &__ts) == -1 && errno == EINTR)
326 __sleep_for(__s, __ns);
331 template<typename _Clock, typename _Duration>
333 sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
335 auto __now = _Clock::now();
336 if (_Clock::is_steady)
339 sleep_for(__atime - __now);
342 while (__now < __atime)
344 sleep_for(__atime - __now);
345 __now = _Clock::now();
349 _GLIBCXX_END_NAMESPACE_VERSION
356#endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
360#endif // _GLIBCXX_THREAD