1 // <condition_variable> -*- C++ -*- 2 3 // Copyright (C) 2008, 2009, 2010 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/condition_variable 26 * This is a Standard C++ Library header. 27 */ 28 29 #ifndef _GLIBCXX_CONDITION_VARIABLE 30 #define _GLIBCXX_CONDITION_VARIABLE 1 31 32 #pragma GCC system_header 33 34 #ifndef __GXX_EXPERIMENTAL_CXX0X__ 35 # include <bits/c++0x_warning.h> 36 #else 37 38 #include <chrono> 39 #include <mutex> // unique_lock 40 41 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1) 42 43 namespace std _GLIBCXX_VISIBILITY(default) 44 { 45 _GLIBCXX_BEGIN_NAMESPACE_VERSION 46 47 /** 48 * @defgroup condition_variables Condition Variables 49 * @ingroup concurrency 50 * 51 * Classes for condition_variable support. 52 * @{ 53 */ 54 55 /// cv_status 56 enum class cv_status { no_timeout, timeout }; 57 58 /// condition_variable 59 class condition_variable 60 { 61 typedef chrono::system_clock __clock_t; 62 typedef __gthread_cond_t __native_type; 63 __native_type _M_cond; 64 65 public: 66 typedef __native_type* native_handle_type; 67 68 condition_variable() throw (); 69 ~condition_variable() throw (); 70 71 condition_variable(const condition_variable&) = delete; 72 condition_variable& operator=(const condition_variable&) = delete; 73 74 void 75 notify_one(); 76 77 void 78 notify_all(); 79 80 void 81 wait(unique_lock<mutex>& __lock); 82 83 template<typename _Predicate> 84 void 85 wait(unique_lock<mutex>& __lock, _Predicate __p) 86 { 87 while (!__p()) 88 wait(__lock); 89 } 90 91 template<typename _Duration> 92 cv_status 93 wait_until(unique_lock<mutex>& __lock, 94 const chrono::time_point<__clock_t, _Duration>& __atime) 95 { return __wait_until_impl(__lock, __atime); } 96 97 template<typename _Clock, typename _Duration> 98 cv_status 99 wait_until(unique_lock<mutex>& __lock, 100 const chrono::time_point<_Clock, _Duration>& __atime) 101 { 102 // DR 887 - Sync unknown clock to known clock. 103 const typename _Clock::time_point __c_entry = _Clock::now(); 104 const __clock_t::time_point __s_entry = __clock_t::now(); 105 const chrono::nanoseconds __delta = __atime - __c_entry; 106 const __clock_t::time_point __s_atime = __s_entry + __delta; 107 108 return __wait_until_impl(__lock, __s_atime); 109 } 110 111 template<typename _Clock, typename _Duration, typename _Predicate> 112 bool 113 wait_until(unique_lock<mutex>& __lock, 114 const chrono::time_point<_Clock, _Duration>& __atime, 115 _Predicate __p) 116 { 117 while (!__p()) 118 if (wait_until(__lock, __atime) == cv_status::timeout) 119 return __p(); 120 return true; 121 } 122 123 template<typename _Rep, typename _Period> 124 cv_status 125 wait_for(unique_lock<mutex>& __lock, 126 const chrono::duration<_Rep, _Period>& __rtime) 127 { return wait_until(__lock, __clock_t::now() + __rtime); } 128 129 template<typename _Rep, typename _Period, typename _Predicate> 130 bool 131 wait_for(unique_lock<mutex>& __lock, 132 const chrono::duration<_Rep, _Period>& __rtime, 133 _Predicate __p) 134 { return wait_until(__lock, __clock_t::now() + __rtime, std::move(__p)); } 135 136 native_handle_type 137 native_handle() 138 { return &_M_cond; } 139 140 private: 141 template<typename _Clock, typename _Duration> 142 cv_status 143 __wait_until_impl(unique_lock<mutex>& __lock, 144 const chrono::time_point<_Clock, _Duration>& __atime) 145 { 146 chrono::time_point<__clock_t, chrono::seconds> __s = 147 chrono::time_point_cast<chrono::seconds>(__atime); 148 149 chrono::nanoseconds __ns = 150 chrono::duration_cast<chrono::nanoseconds>(__atime - __s); 151 152 __gthread_time_t __ts = 153 { 154 static_cast<std::time_t>(__s.time_since_epoch().count()), 155 static_cast<long>(__ns.count()) 156 }; 157 158 __gthread_cond_timedwait(&_M_cond, __lock.mutex()->native_handle(), 159 &__ts); 160 161 return (_Clock::now() < __atime 162 ? cv_status::no_timeout : cv_status::timeout); 163 } 164 }; 165 166 /// condition_variable_any 167 // Like above, but mutex is not required to have try_lock. 168 class condition_variable_any 169 { 170 typedef chrono::system_clock __clock_t; 171 condition_variable _M_cond; 172 mutex _M_mutex; 173 174 public: 175 typedef condition_variable::native_handle_type native_handle_type; 176 177 condition_variable_any() throw (); 178 ~condition_variable_any() throw (); 179 180 condition_variable_any(const condition_variable_any&) = delete; 181 condition_variable_any& operator=(const condition_variable_any&) = delete; 182 183 void 184 notify_one() 185 { 186 lock_guard<mutex> __lock(_M_mutex); 187 _M_cond.notify_one(); 188 } 189 190 void 191 notify_all() 192 { 193 lock_guard<mutex> __lock(_M_mutex); 194 _M_cond.notify_all(); 195 } 196 197 template<typename _Lock> 198 void 199 wait(_Lock& __lock) 200 { 201 // scoped unlock - unlocks in ctor, re-locks in dtor 202 struct _Unlock { 203 explicit _Unlock(_Lock& __lk) : _M_lock(__lk) { __lk.unlock(); } 204 ~_Unlock() noexcept(false) 205 { 206 if (uncaught_exception()) 207 __try { _M_lock.lock(); } __catch(...) { } 208 else 209 _M_lock.lock(); 210 } 211 _Lock& _M_lock; 212 }; 213 214 unique_lock<mutex> __my_lock(_M_mutex); 215 _Unlock __unlock(__lock); 216 // _M_mutex must be unlocked before re-locking __lock so move 217 // ownership of _M_mutex lock to an object with shorter lifetime. 218 unique_lock<mutex> __my_lock2(std::move(__my_lock)); 219 _M_cond.wait(__my_lock2); 220 } 221 222 223 template<typename _Lock, typename _Predicate> 224 void 225 wait(_Lock& __lock, _Predicate __p) 226 { 227 while (!__p()) 228 wait(__lock); 229 } 230 231 template<typename _Lock, typename _Clock, typename _Duration> 232 cv_status 233 wait_until(_Lock& __lock, 234 const chrono::time_point<_Clock, _Duration>& __atime) 235 { 236 unique_lock<mutex> __my_lock(_M_mutex); 237 __lock.unlock(); 238 cv_status __status = _M_cond.wait_until(__my_lock, __atime); 239 __lock.lock(); 240 return __status; 241 } 242 243 template<typename _Lock, typename _Clock, 244 typename _Duration, typename _Predicate> 245 bool 246 wait_until(_Lock& __lock, 247 const chrono::time_point<_Clock, _Duration>& __atime, 248 _Predicate __p) 249 { 250 while (!__p()) 251 if (wait_until(__lock, __atime) == cv_status::timeout) 252 return __p(); 253 return true; 254 } 255 256 template<typename _Lock, typename _Rep, typename _Period> 257 cv_status 258 wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __rtime) 259 { return wait_until(__lock, __clock_t::now() + __rtime); } 260 261 template<typename _Lock, typename _Rep, 262 typename _Period, typename _Predicate> 263 bool 264 wait_for(_Lock& __lock, 265 const chrono::duration<_Rep, _Period>& __rtime, _Predicate __p) 266 { return wait_until(__lock, __clock_t::now() + __rtime, std::move(__p)); } 267 268 native_handle_type 269 native_handle() 270 { return _M_cond.native_handle(); } 271 }; 272 273 // @} group condition_variables 274 _GLIBCXX_END_NAMESPACE_VERSION 275 } // namespace 276 277 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1 278 279 #endif // __GXX_EXPERIMENTAL_CXX0X__ 280 281 #endif // _GLIBCXX_CONDITION_VARIABLE 282
