3 // Copyright (C) 2003-2014 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/mutex
26 * This is a Standard C++ Library header.
29 #ifndef _GLIBCXX_MUTEX
30 #define _GLIBCXX_MUTEX 1
32 #pragma GCC system_header
34 #if __cplusplus < 201103L
35 # include <bits/c++0x_warning.h>
41 #include <type_traits>
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>
49 #ifdef _GLIBCXX_USE_C99_STDINT_TR1
51 namespace std _GLIBCXX_VISIBILITY(default)
53 _GLIBCXX_BEGIN_NAMESPACE_VERSION
55 #ifdef _GLIBCXX_HAS_GTHREADS
56 // Common base class for std::mutex and std::timed_mutex
60 typedef __gthread_mutex_t __native_type;
62 #ifdef __GTHREAD_MUTEX_INIT
63 __native_type _M_mutex = __GTHREAD_MUTEX_INIT;
65 constexpr __mutex_base() noexcept = default;
67 __native_type _M_mutex;
69 __mutex_base() noexcept
71 // XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)
72 __GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex);
75 ~__mutex_base() noexcept { __gthread_mutex_destroy(&_M_mutex); }
78 __mutex_base(const __mutex_base&) = delete;
79 __mutex_base& operator=(const __mutex_base&) = delete;
82 // Common base class for std::recursive_mutex and std::recursive_timed_mutex
83 class __recursive_mutex_base
86 typedef __gthread_recursive_mutex_t __native_type;
88 __recursive_mutex_base(const __recursive_mutex_base&) = delete;
89 __recursive_mutex_base& operator=(const __recursive_mutex_base&) = delete;
91 #ifdef __GTHREAD_RECURSIVE_MUTEX_INIT
92 __native_type _M_mutex = __GTHREAD_RECURSIVE_MUTEX_INIT;
94 __recursive_mutex_base() = default;
96 __native_type _M_mutex;
98 __recursive_mutex_base()
100 // XXX EAGAIN, ENOMEM, EPERM, EBUSY(may), EINVAL(may)
101 __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex);
104 ~__recursive_mutex_base()
105 { __gthread_recursive_mutex_destroy(&_M_mutex); }
110 * @defgroup mutexes Mutexes
111 * @ingroup concurrency
113 * Classes for mutex support.
118 class mutex : private __mutex_base
121 typedef __native_type* native_handle_type;
123 #ifdef __GTHREAD_MUTEX_INIT
126 mutex() noexcept = default;
129 mutex(const mutex&) = delete;
130 mutex& operator=(const mutex&) = delete;
135 int __e = __gthread_mutex_lock(&_M_mutex);
137 // EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)
139 __throw_system_error(__e);
145 // XXX EINVAL, EAGAIN, EBUSY
146 return !__gthread_mutex_trylock(&_M_mutex);
152 // XXX EINVAL, EAGAIN, EPERM
153 __gthread_mutex_unlock(&_M_mutex);
158 { return &_M_mutex; }
162 class recursive_mutex : private __recursive_mutex_base
165 typedef __native_type* native_handle_type;
167 recursive_mutex() = default;
168 ~recursive_mutex() = default;
170 recursive_mutex(const recursive_mutex&) = delete;
171 recursive_mutex& operator=(const recursive_mutex&) = delete;
176 int __e = __gthread_recursive_mutex_lock(&_M_mutex);
178 // EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)
180 __throw_system_error(__e);
186 // XXX EINVAL, EAGAIN, EBUSY
187 return !__gthread_recursive_mutex_trylock(&_M_mutex);
193 // XXX EINVAL, EAGAIN, EBUSY
194 __gthread_recursive_mutex_unlock(&_M_mutex);
199 { return &_M_mutex; }
202 #if _GTHREAD_USE_MUTEX_TIMEDLOCK
203 template<typename _Derived>
204 class __timed_mutex_impl
207 typedef chrono::high_resolution_clock __clock_t;
209 template<typename _Rep, typename _Period>
211 _M_try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
213 using chrono::steady_clock;
214 auto __rt = chrono::duration_cast<steady_clock::duration>(__rtime);
215 if (ratio_greater<steady_clock::period, _Period>())
217 return _M_try_lock_until(steady_clock::now() + __rt);
220 template<typename _Duration>
222 _M_try_lock_until(const chrono::time_point<__clock_t,
225 auto __s = chrono::time_point_cast<chrono::seconds>(__atime);
226 auto __ns = chrono::duration_cast<chrono::nanoseconds>(__atime - __s);
228 __gthread_time_t __ts = {
229 static_cast<std::time_t>(__s.time_since_epoch().count()),
230 static_cast<long>(__ns.count())
233 auto __mutex = static_cast<_Derived*>(this)->native_handle();
234 return !__gthread_mutex_timedlock(__mutex, &__ts);
237 template<typename _Clock, typename _Duration>
239 _M_try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
241 auto __rtime = __atime - _Clock::now();
242 return _M_try_lock_until(__clock_t::now() + __rtime);
248 : private __mutex_base, public __timed_mutex_impl<timed_mutex>
251 typedef __native_type* native_handle_type;
253 timed_mutex() = default;
254 ~timed_mutex() = default;
256 timed_mutex(const timed_mutex&) = delete;
257 timed_mutex& operator=(const timed_mutex&) = delete;
262 int __e = __gthread_mutex_lock(&_M_mutex);
264 // EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)
266 __throw_system_error(__e);
272 // XXX EINVAL, EAGAIN, EBUSY
273 return !__gthread_mutex_trylock(&_M_mutex);
276 template <class _Rep, class _Period>
278 try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
279 { return _M_try_lock_for(__rtime); }
281 template <class _Clock, class _Duration>
283 try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
284 { return _M_try_lock_until(__atime); }
289 // XXX EINVAL, EAGAIN, EBUSY
290 __gthread_mutex_unlock(&_M_mutex);
295 { return &_M_mutex; }
298 /// recursive_timed_mutex
299 class recursive_timed_mutex
300 : private __recursive_mutex_base,
301 public __timed_mutex_impl<recursive_timed_mutex>
304 typedef __native_type* native_handle_type;
306 recursive_timed_mutex() = default;
307 ~recursive_timed_mutex() = default;
309 recursive_timed_mutex(const recursive_timed_mutex&) = delete;
310 recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;
315 int __e = __gthread_recursive_mutex_lock(&_M_mutex);
317 // EINVAL, EAGAIN, EBUSY, EINVAL, EDEADLK(may)
319 __throw_system_error(__e);
325 // XXX EINVAL, EAGAIN, EBUSY
326 return !__gthread_recursive_mutex_trylock(&_M_mutex);
329 template <class _Rep, class _Period>
331 try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
332 { return _M_try_lock_for(__rtime); }
334 template <class _Clock, class _Duration>
336 try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
337 { return _M_try_lock_until(__atime); }
342 // XXX EINVAL, EAGAIN, EBUSY
343 __gthread_recursive_mutex_unlock(&_M_mutex);
348 { return &_M_mutex; }
351 #endif // _GLIBCXX_HAS_GTHREADS
353 /// Do not acquire ownership of the mutex.
354 struct defer_lock_t { };
356 /// Try to acquire ownership of the mutex without blocking.
357 struct try_to_lock_t { };
359 /// Assume the calling thread has already obtained mutex ownership
361 struct adopt_lock_t { };
363 constexpr defer_lock_t defer_lock { };
364 constexpr try_to_lock_t try_to_lock { };
365 constexpr adopt_lock_t adopt_lock { };
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>
374 typedef _Mutex mutex_type;
376 explicit lock_guard(mutex_type& __m) : _M_device(__m)
377 { _M_device.lock(); }
379 lock_guard(mutex_type& __m, adopt_lock_t) : _M_device(__m)
380 { } // calling thread owns mutex
383 { _M_device.unlock(); }
385 lock_guard(const lock_guard&) = delete;
386 lock_guard& operator=(const lock_guard&) = delete;
389 mutex_type& _M_device;
393 template<typename _Mutex>
397 typedef _Mutex mutex_type;
399 unique_lock() noexcept
400 : _M_device(0), _M_owns(false)
403 explicit unique_lock(mutex_type& __m)
404 : _M_device(std::__addressof(__m)), _M_owns(false)
410 unique_lock(mutex_type& __m, defer_lock_t) noexcept
411 : _M_device(std::__addressof(__m)), _M_owns(false)
414 unique_lock(mutex_type& __m, try_to_lock_t)
415 : _M_device(std::__addressof(__m)), _M_owns(_M_device->try_lock())
418 unique_lock(mutex_type& __m, adopt_lock_t)
419 : _M_device(std::__addressof(__m)), _M_owns(true)
421 // XXX calling thread owns mutex
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))
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))
444 unique_lock(const unique_lock&) = delete;
445 unique_lock& operator=(const unique_lock&) = delete;
447 unique_lock(unique_lock&& __u) noexcept
448 : _M_device(__u._M_device), _M_owns(__u._M_owns)
454 unique_lock& operator=(unique_lock&& __u) noexcept
459 unique_lock(std::move(__u)).swap(*this);
471 __throw_system_error(int(errc::operation_not_permitted));
473 __throw_system_error(int(errc::resource_deadlock_would_occur));
485 __throw_system_error(int(errc::operation_not_permitted));
487 __throw_system_error(int(errc::resource_deadlock_would_occur));
490 _M_owns = _M_device->try_lock();
495 template<typename _Clock, typename _Duration>
497 try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime)
500 __throw_system_error(int(errc::operation_not_permitted));
502 __throw_system_error(int(errc::resource_deadlock_would_occur));
505 _M_owns = _M_device->try_lock_until(__atime);
510 template<typename _Rep, typename _Period>
512 try_lock_for(const chrono::duration<_Rep, _Period>& __rtime)
515 __throw_system_error(int(errc::operation_not_permitted));
517 __throw_system_error(int(errc::resource_deadlock_would_occur));
520 _M_owns = _M_device->try_lock_for(__rtime);
529 __throw_system_error(int(errc::operation_not_permitted));
538 swap(unique_lock& __u) noexcept
540 std::swap(_M_device, __u._M_device);
541 std::swap(_M_owns, __u._M_owns);
547 mutex_type* __ret = _M_device;
554 owns_lock() const noexcept
557 explicit operator bool() const noexcept
558 { return owns_lock(); }
561 mutex() const noexcept
562 { return _M_device; }
565 mutex_type* _M_device;
566 bool _M_owns; // XXX use atomic_bool
569 /// Swap overload for unique_lock objects.
570 template<typename _Mutex>
572 swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) noexcept
575 template<typename _Lock>
576 inline unique_lock<_Lock>
577 __try_to_lock(_Lock& __l)
578 { return unique_lock<_Lock>{__l, try_to_lock}; }
580 template<int _Idx, bool _Continue = true>
581 struct __try_lock_impl
583 template<typename... _Lock>
585 __do_try_lock(tuple<_Lock&...>& __locks, int& __idx)
588 auto __lock = std::__try_to_lock(std::get<_Idx>(__locks));
589 if (__lock.owns_lock())
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);
601 struct __try_lock_impl<_Idx, false>
603 template<typename... _Lock>
605 __do_try_lock(tuple<_Lock&...>& __locks, int& __idx)
608 auto __lock = std::__try_to_lock(std::get<_Idx>(__locks));
609 if (__lock.owns_lock())
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.
625 * Sequentially calls try_lock() on each argument.
627 template<typename _Lock1, typename _Lock2, typename... _Lock3>
629 try_lock(_Lock1& __l1, _Lock2& __l2, _Lock3&... __l3)
632 auto __locks = std::tie(__l1, __l2, __l3...);
634 { __try_lock_impl<0>::__do_try_lock(__locks, __idx); }
635 __catch(const __cxxabiv1::__forced_unwind&)
636 { __throw_exception_again; }
642 /** @brief Generic lock.
643 * @param __l1 Meets Mutex requirements (try_lock() may throw).
644 * @param __l2 Meets Mutex requirements (try_lock() may throw).
645 * @param __l3 Meets Mutex requirements (try_lock() may throw).
646 * @throw An exception thrown by an argument's lock() or try_lock() member.
647 * @post All arguments are locked.
649 * All arguments are locked via a sequence of calls to lock(), try_lock()
650 * and unlock(). If the call exits via an exception any locks that were
651 * obtained will be released.
653 template<typename _L1, typename _L2, typename... _L3>
655 lock(_L1& __l1, _L2& __l2, _L3&... __l3)
659 using __try_locker = __try_lock_impl<0, sizeof...(_L3) != 0>;
660 unique_lock<_L1> __first(__l1);
662 auto __locks = std::tie(__l2, __l3...);
663 __try_locker::__do_try_lock(__locks, __idx);
672 #ifdef _GLIBCXX_HAS_GTHREADS
677 typedef __gthread_once_t __native_type;
678 __native_type _M_once = __GTHREAD_ONCE_INIT;
682 constexpr once_flag() noexcept = default;
684 /// Deleted copy constructor
685 once_flag(const once_flag&) = delete;
686 /// Deleted assignment operator
687 once_flag& operator=(const once_flag&) = delete;
689 template<typename _Callable, typename... _Args>
691 call_once(once_flag& __once, _Callable&& __f, _Args&&... __args);
694 #ifdef _GLIBCXX_HAVE_TLS
695 extern __thread void* __once_callable;
696 extern __thread void (*__once_call)();
698 template<typename _Callable>
702 (*(_Callable*)__once_callable)();
705 extern function<void()> __once_functor;
708 __set_once_functor_lock_ptr(unique_lock<mutex>*);
714 extern "C" void __once_proxy(void);
717 template<typename _Callable, typename... _Args>
719 call_once(once_flag& __once, _Callable&& __f, _Args&&... __args)
721 #ifdef _GLIBCXX_HAVE_TLS
722 auto __bound_functor = std::__bind_simple(std::forward<_Callable>(__f),
723 std::forward<_Args>(__args)...);
724 __once_callable = std::__addressof(__bound_functor);
725 __once_call = &__once_call_impl<decltype(__bound_functor)>;
727 unique_lock<mutex> __functor_lock(__get_once_mutex());
728 auto __callable = std::__bind_simple(std::forward<_Callable>(__f),
729 std::forward<_Args>(__args)...);
730 __once_functor = [&]() { __callable(); };
731 __set_once_functor_lock_ptr(&__functor_lock);
734 int __e = __gthread_once(&__once._M_once, &__once_proxy);
736 #ifndef _GLIBCXX_HAVE_TLS
738 __set_once_functor_lock_ptr(0);
742 __throw_system_error(__e);
744 #endif // _GLIBCXX_HAS_GTHREADS
747 _GLIBCXX_END_NAMESPACE_VERSION
749 #endif // _GLIBCXX_USE_C99_STDINT_TR1
753 #endif // _GLIBCXX_MUTEX