1// <thread> -*- C++ -*- 2 3// Copyright (C) 2008-2015 Free Software Foundation, Inc. 4// 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) 9// any later version. 10 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. 15 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. 19 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/>. 24 25/** @file include/thread 26 * This is a Standard C++ Library header. 27 */ 28 29#ifndef _GLIBCXX_THREAD 30#define _GLIBCXX_THREAD 1 31 32#pragma GCC system_header 33 34#if __cplusplus < 201103L 35# include <bits/c++0x_warning.h> 36#else 37 38#include <chrono> 39#include <functional> 40#include <memory> 41#include <bits/functexcept.h> 42#include <bits/functional_hash.h> 43#include <bits/gthr.h> 44 45#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1) 46 47namespace std _GLIBCXX_VISIBILITY(default) 48{ 49_GLIBCXX_BEGIN_NAMESPACE_VERSION 50 51 /** 52 * @defgroup threads Threads 53 * @ingroup concurrency 54 * 55 * Classes for thread support. 56 * @{ 57 */ 58 59 /// thread 60 class thread 61 { 62 public: 63 typedef __gthread_t native_handle_type; 64 struct _Impl_base; 65 typedef shared_ptr<_Impl_base> __shared_base_type; 66 67 /// thread::id 68 class id 69 { 70 native_handle_type _M_thread; 71 72 public: 73 id() noexcept : _M_thread() { } 74 75 explicit 76 id(native_handle_type __id) : _M_thread(__id) { } 77 78 private: 79 friend class thread; 80 friend class hash<thread::id>; 81 82 friend bool 83 operator==(thread::id __x, thread::id __y) noexcept 84 { return __gthread_equal(__x._M_thread, __y._M_thread); } 85 86 friend bool 87 operator<(thread::id __x, thread::id __y) noexcept 88 { return __x._M_thread < __y._M_thread; } 89 90 template<class _CharT, class _Traits> 91 friend basic_ostream<_CharT, _Traits>& 92 operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id); 93 }; 94 95 // Simple base type that the templatized, derived class containing 96 // an arbitrary functor can be converted to and called. 97 struct _Impl_base 98 { 99 __shared_base_type _M_this_ptr; 100 101 inline virtual ~_Impl_base(); 102 103 virtual void _M_run() = 0; 104 }; 105 106 template<typename _Callable> 107 struct _Impl : public _Impl_base 108 { 109 _Callable _M_func; 110 111 _Impl(_Callable&& __f) : _M_func(std::forward<_Callable>(__f)) 112 { } 113 114 void 115 _M_run() { _M_func(); } 116 }; 117 118 private: 119 id _M_id; 120 121 public: 122 thread() noexcept = default; 123 // _GLIBCXX_RESOLVE_LIB_DEFECTS 124 // 2097. packaged_task constructors should be constrained 125 thread(thread&) = delete; 126 thread(const thread&) = delete; 127 thread(const thread&&) = delete; 128 129 thread(thread&& __t) noexcept 130 { swap(__t); } 131 132 template<typename _Callable, typename... _Args> 133 explicit 134 thread(_Callable&& __f, _Args&&... __args) 135 { 136#ifdef GTHR_ACTIVE_PROXY 137 // Create a reference to pthread_create, not just the gthr weak symbol 138 _M_start_thread(_M_make_routine(std::__bind_simple( 139 std::forward<_Callable>(__f), 140 std::forward<_Args>(__args)...)), 141 reinterpret_cast<void(*)()>(&pthread_create)); 142#else 143 _M_start_thread(_M_make_routine(std::__bind_simple( 144 std::forward<_Callable>(__f), 145 std::forward<_Args>(__args)...))); 146#endif 147 } 148 149 ~thread() 150 { 151 if (joinable()) 152 std::terminate(); 153 } 154 155 thread& operator=(const thread&) = delete; 156 157 thread& operator=(thread&& __t) noexcept 158 { 159 if (joinable()) 160 std::terminate(); 161 swap(__t); 162 return *this; 163 } 164 165 void 166 swap(thread& __t) noexcept 167 { std::swap(_M_id, __t._M_id); } 168 169 bool 170 joinable() const noexcept 171 { return !(_M_id == id()); } 172 173 void 174 join(); 175 176 void 177 detach(); 178 179 thread::id 180 get_id() const noexcept 181 { return _M_id; } 182 183 /** @pre thread is joinable 184 */ 185 native_handle_type 186 native_handle() 187 { return _M_id._M_thread; } 188 189 // Returns a value that hints at the number of hardware thread contexts. 190 static unsigned int 191 hardware_concurrency() noexcept; 192 193 private: 194 void 195 _M_start_thread(__shared_base_type, void (*)()); 196 197 void 198 _M_start_thread(__shared_base_type); 199 200 template<typename _Callable> 201 shared_ptr<_Impl<_Callable>> 202 _M_make_routine(_Callable&& __f) 203 { 204 // Create and allocate full data structure, not base. 205 return std::make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f)); 206 } 207 }; 208 209 inline thread::_Impl_base::~_Impl_base() = default; 210 211 inline void 212 swap(thread& __x, thread& __y) noexcept 213 { __x.swap(__y); } 214 215 inline bool 216 operator!=(thread::id __x, thread::id __y) noexcept 217 { return !(__x == __y); } 218 219 inline bool 220 operator<=(thread::id __x, thread::id __y) noexcept 221 { return !(__y < __x); } 222 223 inline bool 224 operator>(thread::id __x, thread::id __y) noexcept 225 { return __y < __x; } 226 227 inline bool 228 operator>=(thread::id __x, thread::id __y) noexcept 229 { return !(__x < __y); } 230 231 // DR 889. 232 /// std::hash specialization for thread::id. 233 template<> 234 struct hash<thread::id> 235 : public __hash_base<size_t, thread::id> 236 { 237 size_t 238 operator()(const thread::id& __id) const noexcept 239 { return std::_Hash_impl::hash(__id._M_thread); } 240 }; 241 242 template<class _CharT, class _Traits> 243 inline basic_ostream<_CharT, _Traits>& 244 operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id) 245 { 246 if (__id == thread::id()) 247 return __out << "thread::id of a non-executing thread"; 248 else 249 return __out << __id._M_thread; 250 } 251 252_GLIBCXX_END_NAMESPACE_VERSION 253 254 /** @namespace std::this_thread 255 * @brief ISO C++ 2011 entities sub-namespace for thread. 256 * 30.3.2 Namespace this_thread. 257 */ 258 namespace this_thread 259 { 260 _GLIBCXX_BEGIN_NAMESPACE_VERSION 261 262 /// get_id 263 inline thread::id 264 get_id() noexcept { return thread::id(__gthread_self()); } 265 266 /// yield 267 inline void 268 yield() noexcept 269 { 270#ifdef _GLIBCXX_USE_SCHED_YIELD 271 __gthread_yield(); 272#endif 273 } 274 275 void 276 __sleep_for(chrono::seconds, chrono::nanoseconds); 277 278 /// sleep_for 279 template<typename _Rep, typename _Period> 280 inline void 281 sleep_for(const chrono::duration<_Rep, _Period>& __rtime) 282 { 283 if (__rtime <= __rtime.zero()) 284 return; 285 auto __s = chrono::duration_cast<chrono::seconds>(__rtime); 286 auto __ns = chrono::duration_cast<chrono::nanoseconds>(__rtime - __s); 287#ifdef _GLIBCXX_USE_NANOSLEEP 288 __gthread_time_t __ts = 289 { 290 static_cast<std::time_t>(__s.count()), 291 static_cast<long>(__ns.count()) 292 }; 293 ::nanosleep(&__ts, 0); 294#else 295 __sleep_for(__s, __ns); 296#endif 297 } 298 299 /// sleep_until 300 template<typename _Clock, typename _Duration> 301 inline void 302 sleep_until(const chrono::time_point<_Clock, _Duration>& __atime) 303 { 304 auto __now = _Clock::now(); 305 if (__now < __atime) 306 sleep_for(__atime - __now); 307 } 308 309 _GLIBCXX_END_NAMESPACE_VERSION 310 } 311 312 // @} group threads 313 314} // namespace 315 316#endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1 317 318#endif // C++11 319 320#endif // _GLIBCXX_THREAD 321