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| 1 | // <mutex> -*- C++ -*- | |
| 2 | ||
| 3 | // Copyright (C) 2003-2015 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/mutex | |
| 26 | * This is a Standard C++ Library header. | |
| 27 | */ | |
| 28 | ||
| 29 | #ifndef _GLIBCXX_MUTEX | |
| 30 | #define _GLIBCXX_MUTEX 1 | |
| 31 | ||
| 32 | #pragma GCC system_header | |
| 33 | ||
| 34 | #if __cplusplus < 201103L | |
| 35 | # include <bits/c++0x_warning.h> | |
| 36 | #else | |
| 37 | ||
| 38 | #include <tuple> | |
| 39 | #include <chrono> | |
| 40 | #include <exception> | |
| 41 | #include <type_traits> | |
| 42 | #include <functional> | |
| 43 | #include <system_error> | |
| 44 | #include <bits/functexcept.h> | |
| 45 | #include <bits/gthr.h> | |
| 46 | #include <bits/move.h> // for std::swap | |
| 47 | #include <bits/cxxabi_forced.h> | |
| 48 | ||
| 49 | #ifdef _GLIBCXX_USE_C99_STDINT_TR1 | |
| 50 | ||
| 51 | namespace std _GLIBCXX_VISIBILITY(default) | |
| 52 | { | |
| 53 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
| 54 | ||
| 55 | #ifdef _GLIBCXX_HAS_GTHREADS | |
| 56 | // Common base class for std::mutex and std::timed_mutex | |
| 57 | class __mutex_base | |
| 58 | { | |
| 59 | protected: | |
| 60 | typedef __gthread_mutex_t __native_type; | |
| 61 | ||
| 62 | #ifdef __GTHREAD_MUTEX_INIT | |
| 63 | __native_type _M_mutex = __GTHREAD_MUTEX_INIT; | |
| 64 | ||
| 65 | constexpr __mutex_base() noexcept = default; | |
| 66 | #else | |
| 67 | __native_type _M_mutex; | |
| 68 | ||
| 69 | __mutex_base() noexcept | |
| 70 | { | |
| 71 | // XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may) | |
| 72 | __GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex); | |
| 73 | } | |
| 74 | ||
| 75 | ~__mutex_base() noexcept { __gthread_mutex_destroy(&_M_mutex); } | |
| 76 | #endif | |
| 77 | ||
| 78 | __mutex_base(const __mutex_base&) = delete; | |
| 79 | __mutex_base& operator=(const __mutex_base&) = delete; | |
| 80 | }; | |
| 81 | ||
| 82 | // Common base class for std::recursive_mutex and std::recursive_timed_mutex | |
| 83 | class __recursive_mutex_base | |
| 84 | { | |
| 85 | protected: | |
| 86 | typedef __gthread_recursive_mutex_t __native_type; | |
| 87 | ||
| 88 | __recursive_mutex_base(const __recursive_mutex_base&) = delete; | |
| 89 | __recursive_mutex_base& operator=(const __recursive_mutex_base&) = delete; | |
| 90 | ||
| 91 | #ifdef __GTHREAD_RECURSIVE_MUTEX_INIT | |
| 92 | __native_type _M_mutex = __GTHREAD_RECURSIVE_MUTEX_INIT; | |
| 93 | ||
| 94 | __recursive_mutex_base() = default; | |
| 95 | #else | |
| 96 | __native_type _M_mutex; | |
| 97 | ||
| 98 | __recursive_mutex_base() | |
| 99 | { | |
| 100 | // XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may) | |
| 101 | __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex); | |
| 102 | } | |
| 103 | ||
| 104 | ~__recursive_mutex_base() | |
| 105 | { __gthread_recursive_mutex_destroy(&_M_mutex); } | |
| 106 | #endif | |
| 107 | }; | |
| 108 | ||
| 109 | /** | |
| 110 | * @defgroup mutexes Mutexes | |
| 111 | * @ingroup concurrency | |
| 112 | * | |
| 113 | * Classes for mutex support. | |
| 114 | * @{ | |
| 115 | */ | |
| 116 | ||
| 117 | /// mutex | |
| 118 | class mutex : private __mutex_base | |
| 119 | { | |
| 120 | public: | |
| 121 | typedef __native_type* native_handle_type; | |
| 122 | ||
| 123 | #ifdef __GTHREAD_MUTEX_INIT | |
| 124 | constexpr | |
| 125 | #endif | |
| 126 | mutex() noexcept = default; | |
| 127 | ~mutex() = default; | |
| 128 | ||
| 129 | mutex(const mutex&) = delete; | |
| 130 | mutex& operator=(const mutex&) = delete; | |
| 131 | ||
| 132 | void | |
| 133 | lock() | |
| 134 | { | |
| 135 | int __e = __gthread_mutex_lock(&_M_mutex); | |
| 136 | ||
| 137 | // EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may) | |
| 138 | if (__e) | |
| 139 | __throw_system_error(__e); | |
| 140 | } | |
| 141 | ||
| 142 | bool | |
| 143 | try_lock() noexcept | |
| 144 | { | |
| 145 | // XXX EINVAL, EAGAIN, EBUSY | |
| 146 | return !__gthread_mutex_trylock(&_M_mutex); | |
| 147 | } | |
| 148 | ||
| 149 | void | |
| 150 | unlock() | |
| 151 | { | |
| 152 | // XXX EINVAL, EAGAIN, EPERM | |
| 153 | __gthread_mutex_unlock(&_M_mutex); | |
| 154 | } | |
| 155 | ||
| 156 | native_handle_type | |
| 157 | native_handle() | |
| 158 | { return &_M_mutex; } | |
| 159 | }; | |
| 160 | ||
| 161 | /// recursive_mutex | |
| 162 | class recursive_mutex : private __recursive_mutex_base | |
| 163 | { | |
| 164 | public: | |
| 165 | typedef __native_type* native_handle_type; | |
| 166 | ||
| 167 | recursive_mutex() = default; | |
| 168 | ~recursive_mutex() = default; | |
| 169 | ||
| 170 | recursive_mutex(const recursive_mutex&) = delete; | |
| 171 | recursive_mutex& operator=(const recursive_mutex&) = delete; | |
| 172 | ||
| 173 | void | |
| 174 | lock() | |
| 175 | { | |
| 176 | int __e = __gthread_recursive_mutex_lock(&_M_mutex); | |
| 177 | ||
| 178 | // EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may) | |
| 179 | if (__e) | |
| 180 | __throw_system_error(__e); | |
| 181 | } | |
| 182 | ||
| 183 | bool | |
| 184 | try_lock() noexcept | |
| 185 | { | |
| 186 | // XXX EINVAL, EAGAIN, EBUSY | |
| 187 | return !__gthread_recursive_mutex_trylock(&_M_mutex); | |
| 188 | } | |
| 189 | ||
| 190 | void | |
| 191 | unlock() | |
| 192 | { | |
| 193 | // XXX EINVAL, EAGAIN, EBUSY | |
| 194 | __gthread_recursive_mutex_unlock(&_M_mutex); | |
| 195 | } | |
| 196 | ||
| 197 | native_handle_type | |
| 198 | native_handle() | |
| 199 | { return &_M_mutex; } | |
| 200 | }; | |
| 201 | ||
| 202 | #if _GTHREAD_USE_MUTEX_TIMEDLOCK | |
| 203 | template<typename _Derived> | |
| 204 | class __timed_mutex_impl | |
| 205 | { | |
| 206 | protected: | |
| 207 | typedef chrono::high_resolution_clock __clock_t; | |
| 208 | ||
| 209 | template<typename _Rep, typename _Period> | |
| 210 | bool | |
| 211 | _M_try_lock_for(const chrono::duration<_Rep, _Period>& __rtime) | |
| 212 | { | |
| 213 | using chrono::steady_clock; | |
| 214 | auto __rt = chrono::duration_cast<steady_clock::duration>(__rtime); | |
| 215 | if (ratio_greater<steady_clock::period, _Period>()) | |
| 216 | ++__rt; | |
| 217 | return _M_try_lock_until(steady_clock::now() + __rt); | |
| 218 | } | |
| 219 | ||
| 220 | template<typename _Duration> | |
| 221 | bool | |
| 222 | _M_try_lock_until(const chrono::time_point<__clock_t, | |
| 223 | _Duration>& __atime) | |
| 224 | { | |
| 225 | auto __s = chrono::time_point_cast<chrono::seconds>(__atime); | |
| 226 | auto __ns = chrono::duration_cast<chrono::nanoseconds>(__atime - __s); | |
| 227 | ||
| 228 | __gthread_time_t __ts = { | |
| 229 | static_cast<std::time_t>(__s.time_since_epoch().count()), | |
| 230 | static_cast<long>(__ns.count()) | |
| 231 | }; | |
| 232 | ||
| 233 | auto __mutex = static_cast<_Derived*>(this)->native_handle(); | |
| 234 | return !__gthread_mutex_timedlock(__mutex, &__ts); | |
| 235 | } | |
| 236 | ||
| 237 | template<typename _Clock, typename _Duration> | |
| 238 | bool | |
| 239 | _M_try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime) | |
| 240 | { | |
| 241 | auto __rtime = __atime - _Clock::now(); | |
| 242 | return _M_try_lock_until(__clock_t::now() + __rtime); | |
| 243 | } | |
| 244 | }; | |
| 245 | ||
| 246 | /// timed_mutex | |
| 247 | class timed_mutex | |
| 248 | : private __mutex_base, public __timed_mutex_impl<timed_mutex> | |
| 249 | { | |
| 250 | public: | |
| 251 | typedef __native_type* native_handle_type; | |
| 252 | ||
| 253 | timed_mutex() = default; | |
| 254 | ~timed_mutex() = default; | |
| 255 | ||
| 256 | timed_mutex(const timed_mutex&) = delete; | |
| 257 | timed_mutex& operator=(const timed_mutex&) = delete; | |
| 258 | ||
| 259 | void | |
| 260 | lock() | |
| 261 | { | |
| 262 | int __e = __gthread_mutex_lock(&_M_mutex); | |
| 263 | ||
| 264 | // EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may) | |
| 265 | if (__e) | |
| 266 | __throw_system_error(__e); | |
| 267 | } | |
| 268 | ||
| 269 | bool | |
| 270 | try_lock() noexcept | |
| 271 | { | |
| 272 | // XXX EINVAL, EAGAIN, EBUSY | |
| 273 | return !__gthread_mutex_trylock(&_M_mutex); | |
| 274 | } | |
| 275 | ||
| 276 | template <class _Rep, class _Period> | |
| 277 | bool | |
| 278 | try_lock_for(const chrono::duration<_Rep, _Period>& __rtime) | |
| 279 | { return _M_try_lock_for(__rtime); } | |
| 280 | ||
| 281 | template <class _Clock, class _Duration> | |
| 282 | bool | |
| 283 | try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime) | |
| 284 | { return _M_try_lock_until(__atime); } | |
| 285 | ||
| 286 | void | |
| 287 | unlock() | |
| 288 | { | |
| 289 | // XXX EINVAL, EAGAIN, EBUSY | |
| 290 | __gthread_mutex_unlock(&_M_mutex); | |
| 291 | } | |
| 292 | ||
| 293 | native_handle_type | |
| 294 | native_handle() | |
| 295 | { return &_M_mutex; } | |
| 296 | }; | |
| 297 | ||
| 298 | /// recursive_timed_mutex | |
| 299 | class recursive_timed_mutex | |
| 300 | : private __recursive_mutex_base, | |
| 301 | public __timed_mutex_impl<recursive_timed_mutex> | |
| 302 | { | |
| 303 | public: | |
| 304 | typedef __native_type* native_handle_type; | |
| 305 | ||
| 306 | recursive_timed_mutex() = default; | |
| 307 | ~recursive_timed_mutex() = default; | |
| 308 | ||
| 309 | recursive_timed_mutex(const recursive_timed_mutex&) = delete; | |
| 310 | recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete; | |
| 311 | ||
| 312 | void | |
| 313 | lock() | |
| 314 | { | |
| 315 | int __e = __gthread_recursive_mutex_lock(&_M_mutex); | |
| 316 | ||
| 317 | // EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may) | |
| 318 | if (__e) | |
| 319 | __throw_system_error(__e); | |
| 320 | } | |
| 321 | ||
| 322 | bool | |
| 323 | try_lock() noexcept | |
| 324 | { | |
| 325 | // XXX EINVAL, EAGAIN, EBUSY | |
| 326 | return !__gthread_recursive_mutex_trylock(&_M_mutex); | |
| 327 | } | |
| 328 | ||
| 329 | template <class _Rep, class _Period> | |
| 330 | bool | |
| 331 | try_lock_for(const chrono::duration<_Rep, _Period>& __rtime) | |
| 332 | { return _M_try_lock_for(__rtime); } | |
| 333 | ||
| 334 | template <class _Clock, class _Duration> | |
| 335 | bool | |
| 336 | try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime) | |
| 337 | { return _M_try_lock_until(__atime); } | |
| 338 | ||
| 339 | void | |
| 340 | unlock() | |
| 341 | { | |
| 342 | // XXX EINVAL, EAGAIN, EBUSY | |
| 343 | __gthread_recursive_mutex_unlock(&_M_mutex); | |
| 344 | } | |
| 345 | ||
| 346 | native_handle_type | |
| 347 | native_handle() | |
| 348 | { return &_M_mutex; } | |
| 349 | }; | |
| 350 | #endif | |
| 351 | #endif // _GLIBCXX_HAS_GTHREADS | |
| 352 | ||
| 353 | /// Do not acquire ownership of the mutex. | |
| 354 | struct defer_lock_t { }; | |
| 355 | ||
| 356 | /// Try to acquire ownership of the mutex without blocking. | |
| 357 | struct try_to_lock_t { }; | |
| 358 | ||
| 359 | /// Assume the calling thread has already obtained mutex ownership | |
| 360 | /// and manage it. | |
| 361 | struct adopt_lock_t { }; | |
| 362 | ||
| 363 | constexpr defer_lock_t defer_lock { }; | |
| 364 | constexpr try_to_lock_t try_to_lock { }; | |
| 365 | constexpr adopt_lock_t adopt_lock { }; | |
| 366 | ||
| 367 | /// @brief Scoped lock idiom. | |
| 368 | // Acquire the mutex here with a constructor call, then release with | |
| 369 | // the destructor call in accordance with RAII style. | |
| 370 | template<typename _Mutex> | |
| 371 | class lock_guard | |
| 372 | { | |
| 373 | public: | |
| 374 | typedef _Mutex mutex_type; | |
| 375 | ||
| 376 | explicit lock_guard(mutex_type& __m) : _M_device(__m) | |
| 377 | { _M_device.lock(); } | |
| 378 | ||
| 379 | lock_guard(mutex_type& __m, adopt_lock_t) : _M_device(__m) | |
| 380 | { } // calling thread owns mutex | |
| 381 | ||
| 382 | ~lock_guard() | |
| 383 | { _M_device.unlock(); } | |
| 384 | ||
| 385 | lock_guard(const lock_guard&) = delete; | |
| 386 | lock_guard& operator=(const lock_guard&) = delete; | |
| 387 | ||
| 388 | private: | |
| 389 | mutex_type& _M_device; | |
| 390 | }; | |
| 391 | ||
| 392 | /// unique_lock | |
| 393 | template<typename _Mutex> | |
| 394 | class unique_lock | |
| 395 | { | |
| 396 | public: | |
| 397 | typedef _Mutex mutex_type; | |
| 398 | ||
| 399 | unique_lock() noexcept | |
| 400 | : _M_device(0), _M_owns(false) | |
| 401 | { } | |
| 402 | ||
| 403 | explicit unique_lock(mutex_type& __m) | |
| 404 | : _M_device(std::__addressof(__m)), _M_owns(false) | |
| 405 | { | |
| 406 | lock(); | |
| 407 | _M_owns = true; | |
| 408 | } | |
| 409 | ||
| 410 | unique_lock(mutex_type& __m, defer_lock_t) noexcept | |
| 411 | : _M_device(std::__addressof(__m)), _M_owns(false) | |
| 412 | { } | |
| 413 | ||
| 414 | unique_lock(mutex_type& __m, try_to_lock_t) | |
| 415 | : _M_device(std::__addressof(__m)), _M_owns(_M_device->try_lock()) | |
| 416 | { } | |
| 417 | ||
| 418 | unique_lock(mutex_type& __m, adopt_lock_t) | |
| 419 | : _M_device(std::__addressof(__m)), _M_owns(true) | |
| 420 | { | |
| 421 | // XXX calling thread owns mutex | |
| 422 | } | |
| 423 | ||
| 424 | template<typename _Clock, typename _Duration> | |
| 425 | unique_lock(mutex_type& __m, | |
| 426 | const chrono::time_point<_Clock, _Duration>& __atime) | |
| 427 | : _M_device(std::__addressof(__m)), | |
| 428 | _M_owns(_M_device->try_lock_until(__atime)) | |
| 429 | { } | |
| 430 | ||
| 431 | template<typename _Rep, typename _Period> | |
| 432 | unique_lock(mutex_type& __m, | |
| 433 | const chrono::duration<_Rep, _Period>& __rtime) | |
| 434 | : _M_device(std::__addressof(__m)), | |
| 435 | _M_owns(_M_device->try_lock_for(__rtime)) | |
| 436 | { } | |
| 437 | ||
| 438 | ~unique_lock() | |
| 439 | { | |
| 440 | if (_M_owns) | |
| 441 | unlock(); | |
| 442 | } | |
| 443 | ||
| 444 | unique_lock(const unique_lock&) = delete; | |
| 445 | unique_lock& operator=(const unique_lock&) = delete; | |
| 446 | ||
| 447 | unique_lock(unique_lock&& __u) noexcept | |
| 448 | : _M_device(__u._M_device), _M_owns(__u._M_owns) | |
| 449 | { | |
| 450 | __u._M_device = 0; | |
| 451 | __u._M_owns = false; | |
| 452 | } | |
| 453 | ||
| 454 | unique_lock& operator=(unique_lock&& __u) noexcept | |
| 455 | { | |
| 456 | if(_M_owns) | |
| 457 | unlock(); | |
| 458 | ||
| 459 | unique_lock(std::move(__u)).swap(*this); | |
| 460 | ||
| 461 | __u._M_device = 0; | |
| 462 | __u._M_owns = false; | |
| 463 | ||
| 464 | return *this; | |
| 465 | } | |
| 466 | ||
| 467 | void | |
| 468 | lock() | |
| 469 | { | |
| 470 | if (!_M_device) | |
| 471 | __throw_system_error(int(errc::operation_not_permitted)); | |
| 472 | else if (_M_owns) | |
| 473 | __throw_system_error(int(errc::resource_deadlock_would_occur)); | |
| 474 | else | |
| 475 | { | |
| 476 | _M_device->lock(); | |
| 477 | _M_owns = true; | |
| 478 | } | |
| 479 | } | |
| 480 | ||
| 481 | bool | |
| 482 | try_lock() | |
| 483 | { | |
| 484 | if (!_M_device) | |
| 485 | __throw_system_error(int(errc::operation_not_permitted)); | |
| 486 | else if (_M_owns) | |
| 487 | __throw_system_error(int(errc::resource_deadlock_would_occur)); | |
| 488 | else | |
| 489 | { | |
| 490 | _M_owns = _M_device->try_lock(); | |
| 491 | return _M_owns; | |
| 492 | } | |
| 493 | } | |
| 494 | ||
| 495 | template<typename _Clock, typename _Duration> | |
| 496 | bool | |
| 497 | try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime) | |
| 498 | { | |
| 499 | if (!_M_device) | |
| 500 | __throw_system_error(int(errc::operation_not_permitted)); | |
| 501 | else if (_M_owns) | |
| 502 | __throw_system_error(int(errc::resource_deadlock_would_occur)); | |
| 503 | else | |
| 504 | { | |
| 505 | _M_owns = _M_device->try_lock_until(__atime); | |
| 506 | return _M_owns; | |
| 507 | } | |
| 508 | } | |
| 509 | ||
| 510 | template<typename _Rep, typename _Period> | |
| 511 | bool | |
| 512 | try_lock_for(const chrono::duration<_Rep, _Period>& __rtime) | |
| 513 | { | |
| 514 | if (!_M_device) | |
| 515 | __throw_system_error(int(errc::operation_not_permitted)); | |
| 516 | else if (_M_owns) | |
| 517 | __throw_system_error(int(errc::resource_deadlock_would_occur)); | |
| 518 | else | |
| 519 | { | |
| 520 | _M_owns = _M_device->try_lock_for(__rtime); | |
| 521 | return _M_owns; | |
| 522 | } | |
| 523 | } | |
| 524 | ||
| 525 | void | |
| 526 | unlock() | |
| 527 | { | |
| 528 | if (!_M_owns) | |
| 529 | __throw_system_error(int(errc::operation_not_permitted)); | |
| 530 | else if (_M_device) | |
| 531 | { | |
| 532 | _M_device->unlock(); | |
| 533 | _M_owns = false; | |
| 534 | } | |
| 535 | } | |
| 536 | ||
| 537 | void | |
| 538 | swap(unique_lock& __u) noexcept | |
| 539 | { | |
| 540 | std::swap(_M_device, __u._M_device); | |
| 541 | std::swap(_M_owns, __u._M_owns); | |
| 542 | } | |
| 543 | ||
| 544 | mutex_type* | |
| 545 | release() noexcept | |
| 546 | { | |
| 547 | mutex_type* __ret = _M_device; | |
| 548 | _M_device = 0; | |
| 549 | _M_owns = false; | |
| 550 | return __ret; | |
| 551 | } | |
| 552 | ||
| 553 | bool | |
| 554 | owns_lock() const noexcept | |
| 555 | { return _M_owns; } | |
| 556 | ||
| 557 | explicit operator bool() const noexcept | |
| 558 | { return owns_lock(); } | |
| 559 | ||
| 560 | mutex_type* | |
| 561 | mutex() const noexcept | |
| 562 | { return _M_device; } | |
| 563 | ||
| 564 | private: | |
| 565 | mutex_type* _M_device; | |
| 566 | bool _M_owns; // XXX use atomic_bool | |
| 567 | }; | |
| 568 | ||
| 569 | /// Swap overload for unique_lock objects. | |
| 570 | template<typename _Mutex> | |
| 571 | inline void | |
| 572 | swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) noexcept | |
| 573 | { __x.swap(__y); } | |
| 574 | ||
| 575 | template<typename _Lock> | |
| 576 | inline unique_lock<_Lock> | |
| 577 | __try_to_lock(_Lock& __l) | |
| 578 | { return unique_lock<_Lock>{__l, try_to_lock}; } | |
| 579 | ||
| 580 | template<int _Idx, bool _Continue = true> | |
| 581 | struct __try_lock_impl | |
| 582 | { | |
| 583 | template<typename... _Lock> | |
| 584 | static void | |
| 585 | __do_try_lock(tuple<_Lock&...>& __locks, int& __idx) | |
| 586 | { | |
| 587 | __idx = _Idx; | |
| 588 | auto __lock = std::__try_to_lock(std::get<_Idx>(__locks)); | |
| 589 | if (__lock.owns_lock()) | |
| 590 | { | |
| 591 | constexpr bool __cont = _Idx + 2 < sizeof...(_Lock); | |
| 592 | using __try_locker = __try_lock_impl<_Idx + 1, __cont>; | |
| 593 | __try_locker::__do_try_lock(__locks, __idx); | |
| 594 | if (__idx == -1) | |
| 595 | __lock.release(); | |
| 596 | } | |
| 597 | } | |
| 598 | }; | |
| 599 | ||
| 600 | template<int _Idx> | |
| 601 | struct __try_lock_impl<_Idx, false> | |
| 602 | { | |
| 603 | template<typename... _Lock> | |
| 604 | static void | |
| 605 | __do_try_lock(tuple<_Lock&...>& __locks, int& __idx) | |
| 606 | { | |
| 607 | __idx = _Idx; | |
| 608 | auto __lock = std::__try_to_lock(std::get<_Idx>(__locks)); | |
| 609 | if (__lock.owns_lock()) | |
| 610 | { | |
| 611 | __idx = -1; | |
| 612 | __lock.release(); | |
| 613 | } | |
| 614 | } | |
| 615 | }; | |
| 616 | ||
| 617 | /** @brief Generic try_lock. | |
| 618 | * @param __l1 Meets Mutex requirements (try_lock() may throw). | |
| 619 | * @param __l2 Meets Mutex requirements (try_lock() may throw). | |
| 620 | * @param __l3 Meets Mutex requirements (try_lock() may throw). | |
| 621 | * @return Returns -1 if all try_lock() calls return true. Otherwise returns | |
| 622 | * a 0-based index corresponding to the argument that returned false. | |
| 623 | * @post Either all arguments are locked, or none will be. | |
| 624 | * | |
| 625 | * Sequentially calls try_lock() on each argument. | |
| 626 | */ | |
| 627 | template<typename _Lock1, typename _Lock2, typename... _Lock3> | |
| 628 | int | |
| 629 | try_lock(_Lock1& __l1, _Lock2& __l2, _Lock3&... __l3) | |
| 630 | { | |
| 631 | int __idx; | |
| 632 | auto __locks = std::tie(__l1, __l2, __l3...); | |
| 633 | __try_lock_impl<0>::__do_try_lock(__locks, __idx); | |
| 634 | return __idx; | |
| 635 | } | |
| 636 | ||
| 637 | /** @brief Generic lock. | |
| 638 | * @param __l1 Meets Mutex requirements (try_lock() may throw). | |
| 639 | * @param __l2 Meets Mutex requirements (try_lock() may throw). | |
| 640 | * @param __l3 Meets Mutex requirements (try_lock() may throw). | |
| 641 | * @throw An exception thrown by an argument's lock() or try_lock() member. | |
| 642 | * @post All arguments are locked. | |
| 643 | * | |
| 644 | * All arguments are locked via a sequence of calls to lock(), try_lock() | |
| 645 | * and unlock(). If the call exits via an exception any locks that were | |
| 646 | * obtained will be released. | |
| 647 | */ | |
| 648 | template<typename _L1, typename _L2, typename... _L3> | |
| 649 | void | |
| 650 | lock(_L1& __l1, _L2& __l2, _L3&... __l3) | |
| 651 | { | |
| 652 | while (true) | |
| 653 | { | |
| 654 | using __try_locker = __try_lock_impl<0, sizeof...(_L3) != 0>; | |
| 655 | unique_lock<_L1> __first(__l1); | |
| 656 | int __idx; | |
| 657 | auto __locks = std::tie(__l2, __l3...); | |
| 658 | __try_locker::__do_try_lock(__locks, __idx); | |
| 659 | if (__idx == -1) | |
| 660 | { | |
| 661 | __first.release(); | |
| 662 | return; | |
| 663 | } | |
| 664 | } | |
| 665 | } | |
| 666 | ||
| 667 | #ifdef _GLIBCXX_HAS_GTHREADS | |
| 668 | /// once_flag | |
| 669 | struct once_flag | |
| 670 | { | |
| 671 | private: | |
| 672 | typedef __gthread_once_t __native_type; | |
| 673 | __native_type _M_once = __GTHREAD_ONCE_INIT; | |
| 674 | ||
| 675 | public: | |
| 676 | /// Constructor | |
| 677 | constexpr once_flag() noexcept = default; | |
| 678 | ||
| 679 | /// Deleted copy constructor | |
| 680 | once_flag(const once_flag&) = delete; | |
| 681 | /// Deleted assignment operator | |
| 682 | once_flag& operator=(const once_flag&) = delete; | |
| 683 | ||
| 684 | template<typename _Callable, typename... _Args> | |
| 685 | friend void | |
| 686 | call_once(once_flag& __once, _Callable&& __f, _Args&&... __args); | |
| 687 | }; | |
| 688 | ||
| 689 | #ifdef _GLIBCXX_HAVE_TLS | |
| 690 | extern __thread void* __once_callable; | |
| 691 | extern __thread void (*__once_call)(); | |
| 692 | ||
| 693 | template<typename _Callable> | |
| 694 | inline void | |
| 695 | __once_call_impl() | |
| 696 | { | |
| 697 | (*(_Callable*)__once_callable)(); | |
| 698 | } | |
| 699 | #else | |
| 700 | extern function<void()> __once_functor; | |
| 701 | ||
| 702 | extern void | |
| 703 | __set_once_functor_lock_ptr(unique_lock<mutex>*); | |
| 704 | ||
| 705 | extern mutex& | |
| 706 | __get_once_mutex(); | |
| 707 | #endif | |
| 708 | ||
| 709 | extern "C" void __once_proxy(void); | |
| 710 | ||
| 711 | /// call_once | |
| 712 | template<typename _Callable, typename... _Args> | |
| 713 | void | |
| 714 | call_once(once_flag& __once, _Callable&& __f, _Args&&... __args) | |
| 715 | { | |
| 716 | #ifdef _GLIBCXX_HAVE_TLS | |
| 717 | auto __bound_functor = std::__bind_simple(std::forward<_Callable>(__f), | |
| 718 | std::forward<_Args>(__args)...); | |
| 719 | __once_callable = std::__addressof(__bound_functor); | |
| 720 | __once_call = &__once_call_impl<decltype(__bound_functor)>; | |
| 721 | #else | |
| 722 | unique_lock<mutex> __functor_lock(__get_once_mutex()); | |
| 723 | auto __callable = std::__bind_simple(std::forward<_Callable>(__f), | |
| 724 | std::forward<_Args>(__args)...); | |
| 725 | __once_functor = [&]() { __callable(); }; | |
| 726 | __set_once_functor_lock_ptr(&__functor_lock); | |
| 727 | #endif | |
| 728 | ||
| 729 | int __e = __gthread_once(&__once._M_once, &__once_proxy); | |
| 730 | ||
| 731 | #ifndef _GLIBCXX_HAVE_TLS | |
| 732 | if (__functor_lock) | |
| 733 | __set_once_functor_lock_ptr(0); | |
| 734 | #endif | |
| 735 | ||
| 736 | if (__e) | |
| 737 | __throw_system_error(__e); | |
| 738 | } | |
| 739 | #endif // _GLIBCXX_HAS_GTHREADS | |
| 740 | ||
| 741 | // @} group mutexes | |
| 742 | _GLIBCXX_END_NAMESPACE_VERSION | |
| 743 | } // namespace | |
| 744 | #endif // _GLIBCXX_USE_C99_STDINT_TR1 | |
| 745 | ||
| 746 | #endif // C++11 | |
| 747 | ||
| 748 | #endif // _GLIBCXX_MUTEX | |
| 749 |
Copyright (c) 2006-2012 Rogue Wave Software, Inc. All Rights Reserved.
Patents pending.