1 // -*- C++ -*- 2 //===--------------------------- mutex ------------------------------------===// 3 // 4 // The LLVM Compiler Infrastructure 5 // 6 // This file is dual licensed under the MIT and the University of Illinois Open 7 // Source Licenses. See LICENSE.TXT for details. 8 // 9 //===----------------------------------------------------------------------===// 10 11 #ifndef _LIBCPP_MUTEX 12 #define _LIBCPP_MUTEX 13 14 /* 15 mutex synopsis 16 17 namespace std 18 { 19 20 class mutex 21 { 22 public: 23 constexpr mutex() noexcept; 24 ~mutex(); 25 26 mutex(const mutex&) = delete; 27 mutex& operator=(const mutex&) = delete; 28 29 void lock(); 30 bool try_lock(); 31 void unlock(); 32 33 typedef pthread_mutex_t* native_handle_type; 34 native_handle_type native_handle(); 35 }; 36 37 class recursive_mutex 38 { 39 public: 40 recursive_mutex(); 41 ~recursive_mutex(); 42 43 recursive_mutex(const recursive_mutex&) = delete; 44 recursive_mutex& operator=(const recursive_mutex&) = delete; 45 46 void lock(); 47 bool try_lock() noexcept; 48 void unlock(); 49 50 typedef pthread_mutex_t* native_handle_type; 51 native_handle_type native_handle(); 52 }; 53 54 class timed_mutex 55 { 56 public: 57 timed_mutex(); 58 ~timed_mutex(); 59 60 timed_mutex(const timed_mutex&) = delete; 61 timed_mutex& operator=(const timed_mutex&) = delete; 62 63 void lock(); 64 bool try_lock(); 65 template <class Rep, class Period> 66 bool try_lock_for(const chrono::duration<Rep, Period>& rel_time); 67 template <class Clock, class Duration> 68 bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time); 69 void unlock(); 70 }; 71 72 class recursive_timed_mutex 73 { 74 public: 75 recursive_timed_mutex(); 76 ~recursive_timed_mutex(); 77 78 recursive_timed_mutex(const recursive_timed_mutex&) = delete; 79 recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete; 80 81 void lock(); 82 bool try_lock() noexcept; 83 template <class Rep, class Period> 84 bool try_lock_for(const chrono::duration<Rep, Period>& rel_time); 85 template <class Clock, class Duration> 86 bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time); 87 void unlock(); 88 }; 89 90 struct defer_lock_t {}; 91 struct try_to_lock_t {}; 92 struct adopt_lock_t {}; 93 94 constexpr defer_lock_t defer_lock{}; 95 constexpr try_to_lock_t try_to_lock{}; 96 constexpr adopt_lock_t adopt_lock{}; 97 98 template <class Mutex> 99 class lock_guard 100 { 101 public: 102 typedef Mutex mutex_type; 103 104 explicit lock_guard(mutex_type& m); 105 lock_guard(mutex_type& m, adopt_lock_t); 106 ~lock_guard(); 107 108 lock_guard(lock_guard const&) = delete; 109 lock_guard& operator=(lock_guard const&) = delete; 110 }; 111 112 template <class Mutex> 113 class unique_lock 114 { 115 public: 116 typedef Mutex mutex_type; 117 unique_lock() noexcept; 118 explicit unique_lock(mutex_type& m); 119 unique_lock(mutex_type& m, defer_lock_t) noexcept; 120 unique_lock(mutex_type& m, try_to_lock_t); 121 unique_lock(mutex_type& m, adopt_lock_t); 122 template <class Clock, class Duration> 123 unique_lock(mutex_type& m, const chrono::time_point<Clock, Duration>& abs_time); 124 template <class Rep, class Period> 125 unique_lock(mutex_type& m, const chrono::duration<Rep, Period>& rel_time); 126 ~unique_lock(); 127 128 unique_lock(unique_lock const&) = delete; 129 unique_lock& operator=(unique_lock const&) = delete; 130 131 unique_lock(unique_lock&& u) noexcept; 132 unique_lock& operator=(unique_lock&& u) noexcept; 133 134 void lock(); 135 bool try_lock(); 136 137 template <class Rep, class Period> 138 bool try_lock_for(const chrono::duration<Rep, Period>& rel_time); 139 template <class Clock, class Duration> 140 bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time); 141 142 void unlock(); 143 144 void swap(unique_lock& u) noexcept; 145 mutex_type* release() noexcept; 146 147 bool owns_lock() const noexcept; 148 explicit operator bool () const noexcept; 149 mutex_type* mutex() const noexcept; 150 }; 151 152 template <class Mutex> 153 void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y) noexcept; 154 155 template <class L1, class L2, class... L3> 156 int try_lock(L1&, L2&, L3&...); 157 template <class L1, class L2, class... L3> 158 void lock(L1&, L2&, L3&...); 159 160 struct once_flag 161 { 162 constexpr once_flag() noexcept; 163 164 once_flag(const once_flag&) = delete; 165 once_flag& operator=(const once_flag&) = delete; 166 }; 167 168 template<class Callable, class ...Args> 169 void call_once(once_flag& flag, Callable&& func, Args&&... args); 170 171 } // std 172 173 */ 174 175 #include <__config> 176 #include <__mutex_base> 177 #include <functional> 178 #include <memory> 179 #ifndef _LIBCPP_HAS_NO_VARIADICS 180 #include <tuple> 181 #endif 182 #include <sched.h> 183 184 #include <__undef_min_max> 185 186 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 187 #pragma GCC system_header 188 #endif 189 190 _LIBCPP_BEGIN_NAMESPACE_STD 191 192 #ifndef _LIBCPP_HAS_NO_THREADS 193 194 class _LIBCPP_TYPE_VIS recursive_mutex 195 { 196 pthread_mutex_t __m_; 197 198 public: 199 recursive_mutex(); 200 ~recursive_mutex(); 201 202 private: 203 recursive_mutex(const recursive_mutex&); // = delete; 204 recursive_mutex& operator=(const recursive_mutex&); // = delete; 205 206 public: 207 void lock(); 208 bool try_lock() _NOEXCEPT; 209 void unlock() _NOEXCEPT; 210 211 typedef pthread_mutex_t* native_handle_type; 212 _LIBCPP_INLINE_VISIBILITY 213 native_handle_type native_handle() {return &__m_;} 214 }; 215 216 class _LIBCPP_TYPE_VIS timed_mutex 217 { 218 mutex __m_; 219 condition_variable __cv_; 220 bool __locked_; 221 public: 222 timed_mutex(); 223 ~timed_mutex(); 224 225 private: 226 timed_mutex(const timed_mutex&); // = delete; 227 timed_mutex& operator=(const timed_mutex&); // = delete; 228 229 public: 230 void lock(); 231 bool try_lock() _NOEXCEPT; 232 template <class _Rep, class _Period> 233 _LIBCPP_INLINE_VISIBILITY 234 bool try_lock_for(const chrono::duration<_Rep, _Period>& __d) 235 {return try_lock_until(chrono::steady_clock::now() + __d);} 236 template <class _Clock, class _Duration> 237 bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t); 238 void unlock() _NOEXCEPT; 239 }; 240 241 template <class _Clock, class _Duration> 242 bool 243 timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t) 244 { 245 using namespace chrono; 246 unique_lock<mutex> __lk(__m_); 247 bool no_timeout = _Clock::now() < __t; 248 while (no_timeout && __locked_) 249 no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout; 250 if (!__locked_) 251 { 252 __locked_ = true; 253 return true; 254 } 255 return false; 256 } 257 258 class _LIBCPP_TYPE_VIS recursive_timed_mutex 259 { 260 mutex __m_; 261 condition_variable __cv_; 262 size_t __count_; 263 pthread_t __id_; 264 public: 265 recursive_timed_mutex(); 266 ~recursive_timed_mutex(); 267 268 private: 269 recursive_timed_mutex(const recursive_timed_mutex&); // = delete; 270 recursive_timed_mutex& operator=(const recursive_timed_mutex&); // = delete; 271 272 public: 273 void lock(); 274 bool try_lock() _NOEXCEPT; 275 template <class _Rep, class _Period> 276 _LIBCPP_INLINE_VISIBILITY 277 bool try_lock_for(const chrono::duration<_Rep, _Period>& __d) 278 {return try_lock_until(chrono::steady_clock::now() + __d);} 279 template <class _Clock, class _Duration> 280 bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t); 281 void unlock() _NOEXCEPT; 282 }; 283 284 template <class _Clock, class _Duration> 285 bool 286 recursive_timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t) 287 { 288 using namespace chrono; 289 pthread_t __id = pthread_self(); 290 unique_lock<mutex> lk(__m_); 291 if (pthread_equal(__id, __id_)) 292 { 293 if (__count_ == numeric_limits<size_t>::max()) 294 return false; 295 ++__count_; 296 return true; 297 } 298 bool no_timeout = _Clock::now() < __t; 299 while (no_timeout && __count_ != 0) 300 no_timeout = __cv_.wait_until(lk, __t) == cv_status::no_timeout; 301 if (__count_ == 0) 302 { 303 __count_ = 1; 304 __id_ = __id; 305 return true; 306 } 307 return false; 308 } 309 310 template <class _L0, class _L1> 311 int 312 try_lock(_L0& __l0, _L1& __l1) 313 { 314 unique_lock<_L0> __u0(__l0, try_to_lock); 315 if (__u0.owns_lock()) 316 { 317 if (__l1.try_lock()) 318 { 319 __u0.release(); 320 return -1; 321 } 322 else 323 return 1; 324 } 325 return 0; 326 } 327 328 #ifndef _LIBCPP_HAS_NO_VARIADICS 329 330 template <class _L0, class _L1, class _L2, class... _L3> 331 int 332 try_lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) 333 { 334 int __r = 0; 335 unique_lock<_L0> __u0(__l0, try_to_lock); 336 if (__u0.owns_lock()) 337 { 338 __r = try_lock(__l1, __l2, __l3...); 339 if (__r == -1) 340 __u0.release(); 341 else 342 ++__r; 343 } 344 return __r; 345 } 346 347 #endif // _LIBCPP_HAS_NO_VARIADICS 348 349 template <class _L0, class _L1> 350 void 351 lock(_L0& __l0, _L1& __l1) 352 { 353 while (true) 354 { 355 { 356 unique_lock<_L0> __u0(__l0); 357 if (__l1.try_lock()) 358 { 359 __u0.release(); 360 break; 361 } 362 } 363 sched_yield(); 364 { 365 unique_lock<_L1> __u1(__l1); 366 if (__l0.try_lock()) 367 { 368 __u1.release(); 369 break; 370 } 371 } 372 sched_yield(); 373 } 374 } 375 376 #ifndef _LIBCPP_HAS_NO_VARIADICS 377 378 template <class _L0, class _L1, class _L2, class ..._L3> 379 void 380 __lock_first(int __i, _L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3) 381 { 382 while (true) 383 { 384 switch (__i) 385 { 386 case 0: 387 { 388 unique_lock<_L0> __u0(__l0); 389 __i = try_lock(__l1, __l2, __l3...); 390 if (__i == -1) 391 { 392 __u0.release(); 393 return; 394 } 395 } 396 ++__i; 397 sched_yield(); 398 break; 399 case 1: 400 { 401 unique_lock<_L1> __u1(__l1); 402 __i = try_lock(__l2, __l3..., __l0); 403 if (__i == -1) 404 { 405 __u1.release(); 406 return; 407 } 408 } 409 if (__i == sizeof...(_L3) + 1) 410 __i = 0; 411 else 412 __i += 2; 413 sched_yield(); 414 break; 415 default: 416 __lock_first(__i - 2, __l2, __l3..., __l0, __l1); 417 return; 418 } 419 } 420 } 421 422 template <class _L0, class _L1, class _L2, class ..._L3> 423 inline _LIBCPP_INLINE_VISIBILITY 424 void 425 lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3) 426 { 427 __lock_first(0, __l0, __l1, __l2, __l3...); 428 } 429 430 #endif // _LIBCPP_HAS_NO_VARIADICS 431 432 #endif // !_LIBCPP_HAS_NO_THREADS 433 434 struct _LIBCPP_TYPE_VIS_ONLY once_flag; 435 436 #ifndef _LIBCPP_HAS_NO_VARIADICS 437 438 template<class _Callable, class... _Args> 439 _LIBCPP_INLINE_VISIBILITY 440 void call_once(once_flag&, _Callable&&, _Args&&...); 441 442 #else // _LIBCPP_HAS_NO_VARIADICS 443 444 template<class _Callable> 445 _LIBCPP_INLINE_VISIBILITY 446 void call_once(once_flag&, _Callable&); 447 448 template<class _Callable> 449 _LIBCPP_INLINE_VISIBILITY 450 void call_once(once_flag&, const _Callable&); 451 452 #endif // _LIBCPP_HAS_NO_VARIADICS 453 454 struct _LIBCPP_TYPE_VIS_ONLY once_flag 455 { 456 _LIBCPP_INLINE_VISIBILITY 457 _LIBCPP_CONSTEXPR 458 once_flag() _NOEXCEPT : __state_(0) {} 459 460 private: 461 once_flag(const once_flag&); // = delete; 462 once_flag& operator=(const once_flag&); // = delete; 463 464 unsigned long __state_; 465 466 #ifndef _LIBCPP_HAS_NO_VARIADICS 467 template<class _Callable, class... _Args> 468 friend 469 void call_once(once_flag&, _Callable&&, _Args&&...); 470 #else // _LIBCPP_HAS_NO_VARIADICS 471 template<class _Callable> 472 friend 473 void call_once(once_flag&, _Callable&); 474 475 template<class _Callable> 476 friend 477 void call_once(once_flag&, const _Callable&); 478 #endif // _LIBCPP_HAS_NO_VARIADICS 479 }; 480 481 #ifndef _LIBCPP_HAS_NO_VARIADICS 482 483 template <class _Fp> 484 class __call_once_param 485 { 486 _Fp& __f_; 487 public: 488 _LIBCPP_INLINE_VISIBILITY 489 explicit __call_once_param(_Fp& __f) : __f_(__f) {} 490 491 _LIBCPP_INLINE_VISIBILITY 492 void operator()() 493 { 494 typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 1>::type _Index; 495 __execute(_Index()); 496 } 497 498 private: 499 template <size_t ..._Indices> 500 _LIBCPP_INLINE_VISIBILITY 501 void __execute(__tuple_indices<_Indices...>) 502 { 503 __invoke(_VSTD::get<0>(_VSTD::move(__f_)), _VSTD::get<_Indices>(_VSTD::move(__f_))...); 504 } 505 }; 506 507 #else 508 509 template <class _Fp> 510 class __call_once_param 511 { 512 _Fp& __f_; 513 public: 514 _LIBCPP_INLINE_VISIBILITY 515 explicit __call_once_param(_Fp& __f) : __f_(__f) {} 516 517 _LIBCPP_INLINE_VISIBILITY 518 void operator()() 519 { 520 __f_(); 521 } 522 }; 523 524 #endif 525 526 template <class _Fp> 527 void 528 __call_once_proxy(void* __vp) 529 { 530 __call_once_param<_Fp>* __p = static_cast<__call_once_param<_Fp>*>(__vp); 531 (*__p)(); 532 } 533 534 _LIBCPP_FUNC_VIS void __call_once(volatile unsigned long&, void*, void(*)(void*)); 535 536 #ifndef _LIBCPP_HAS_NO_VARIADICS 537 538 template<class _Callable, class... _Args> 539 inline _LIBCPP_INLINE_VISIBILITY 540 void 541 call_once(once_flag& __flag, _Callable&& __func, _Args&&... __args) 542 { 543 if (__libcpp_relaxed_load(&__flag.__state_) != ~0ul) 544 { 545 typedef tuple<_Callable&&, _Args&&...> _Gp; 546 _Gp __f(_VSTD::forward<_Callable>(__func), _VSTD::forward<_Args>(__args)...); 547 __call_once_param<_Gp> __p(__f); 548 __call_once(__flag.__state_, &__p, &__call_once_proxy<_Gp>); 549 } 550 } 551 552 #else // _LIBCPP_HAS_NO_VARIADICS 553 554 template<class _Callable> 555 inline _LIBCPP_INLINE_VISIBILITY 556 void 557 call_once(once_flag& __flag, _Callable& __func) 558 { 559 if (__libcpp_relaxed_load(&__flag.__state_) != ~0ul) 560 { 561 __call_once_param<_Callable> __p(__func); 562 __call_once(__flag.__state_, &__p, &__call_once_proxy<_Callable>); 563 } 564 } 565 566 template<class _Callable> 567 inline _LIBCPP_INLINE_VISIBILITY 568 void 569 call_once(once_flag& __flag, const _Callable& __func) 570 { 571 if (__flag.__state_ != ~0ul) 572 { 573 __call_once_param<const _Callable> __p(__func); 574 __call_once(__flag.__state_, &__p, &__call_once_proxy<const _Callable>); 575 } 576 } 577 578 #endif // _LIBCPP_HAS_NO_VARIADICS 579 580 _LIBCPP_END_NAMESPACE_STD 581 582 #endif // _LIBCPP_MUTEX 583
