• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
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_BASE
12#define _LIBCPP___MUTEX_BASE
13
14#include <__config>
15#include <chrono>
16#include <system_error>
17#include <__threading_support>
18
19#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20#pragma GCC system_header
21#endif
22
23_LIBCPP_BEGIN_NAMESPACE_STD
24
25#ifndef _LIBCPP_HAS_NO_THREADS
26
27#ifndef _LIBCPP_THREAD_SAFETY_ANNOTATION
28#  ifdef _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
29#    define _LIBCPP_THREAD_SAFETY_ANNOTATION(x) __attribute__((x))
30#  else
31#    define _LIBCPP_THREAD_SAFETY_ANNOTATION(x)
32#  endif
33#endif  // _LIBCPP_THREAD_SAFETY_ANNOTATION
34
35class _LIBCPP_TYPE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(capability("mutex")) mutex
36{
37#ifndef _LIBCPP_HAS_NO_CONSTEXPR
38    __libcpp_mutex_t __m_ = _LIBCPP_MUTEX_INITIALIZER;
39#else
40    __libcpp_mutex_t __m_;
41#endif
42
43public:
44    _LIBCPP_INLINE_VISIBILITY
45#ifndef _LIBCPP_HAS_NO_CONSTEXPR
46    constexpr mutex() _NOEXCEPT = default;
47#else
48    mutex() _NOEXCEPT {__m_ = (__libcpp_mutex_t)_LIBCPP_MUTEX_INITIALIZER;}
49#endif
50    ~mutex();
51
52private:
53    mutex(const mutex&);// = delete;
54    mutex& operator=(const mutex&);// = delete;
55
56public:
57    void lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability());
58    bool try_lock() _NOEXCEPT _LIBCPP_THREAD_SAFETY_ANNOTATION(try_acquire_capability(true));
59    void unlock() _NOEXCEPT _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability());
60
61    typedef __libcpp_mutex_t* native_handle_type;
62    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__m_;}
63};
64
65struct _LIBCPP_TYPE_VIS defer_lock_t {};
66struct _LIBCPP_TYPE_VIS try_to_lock_t {};
67struct _LIBCPP_TYPE_VIS adopt_lock_t {};
68
69#if defined(_LIBCPP_HAS_NO_CONSTEXPR) || defined(_LIBCPP_BUILDING_MUTEX)
70
71extern const defer_lock_t  defer_lock;
72extern const try_to_lock_t try_to_lock;
73extern const adopt_lock_t  adopt_lock;
74
75#else
76
77constexpr defer_lock_t  defer_lock  = defer_lock_t();
78constexpr try_to_lock_t try_to_lock = try_to_lock_t();
79constexpr adopt_lock_t  adopt_lock  = adopt_lock_t();
80
81#endif
82
83
84// Forward declare lock_guard as a variadic template even in C++03 to keep
85// the mangling consistent between dialects.
86#if defined(_LIBCPP_ABI_VARIADIC_LOCK_GUARD)
87template <class ..._Mutexes>
88class _LIBCPP_TEMPLATE_VIS lock_guard;
89#endif
90
91template <class _Mutex>
92class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable)
93#if !defined(_LIBCPP_ABI_VARIADIC_LOCK_GUARD)
94lock_guard
95#else
96lock_guard<_Mutex>
97#endif
98{
99public:
100    typedef _Mutex mutex_type;
101
102private:
103    mutex_type& __m_;
104public:
105
106    _LIBCPP_INLINE_VISIBILITY
107    explicit lock_guard(mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
108        : __m_(__m) {__m_.lock();}
109    _LIBCPP_INLINE_VISIBILITY
110    lock_guard(mutex_type& __m, adopt_lock_t) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
111        : __m_(__m) {}
112    _LIBCPP_INLINE_VISIBILITY
113    ~lock_guard() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) {__m_.unlock();}
114
115private:
116    lock_guard(lock_guard const&) _LIBCPP_EQUAL_DELETE;
117    lock_guard& operator=(lock_guard const&) _LIBCPP_EQUAL_DELETE;
118};
119
120template <class _Mutex>
121class _LIBCPP_TEMPLATE_VIS unique_lock
122{
123public:
124    typedef _Mutex mutex_type;
125
126private:
127    mutex_type* __m_;
128    bool __owns_;
129
130public:
131    _LIBCPP_INLINE_VISIBILITY
132    unique_lock() _NOEXCEPT : __m_(nullptr), __owns_(false) {}
133    _LIBCPP_INLINE_VISIBILITY
134    explicit unique_lock(mutex_type& __m)
135        : __m_(_VSTD::addressof(__m)), __owns_(true) {__m_->lock();}
136    _LIBCPP_INLINE_VISIBILITY
137    unique_lock(mutex_type& __m, defer_lock_t) _NOEXCEPT
138        : __m_(_VSTD::addressof(__m)), __owns_(false) {}
139    _LIBCPP_INLINE_VISIBILITY
140    unique_lock(mutex_type& __m, try_to_lock_t)
141        : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock()) {}
142    _LIBCPP_INLINE_VISIBILITY
143    unique_lock(mutex_type& __m, adopt_lock_t)
144        : __m_(_VSTD::addressof(__m)), __owns_(true) {}
145    template <class _Clock, class _Duration>
146    _LIBCPP_INLINE_VISIBILITY
147        unique_lock(mutex_type& __m, const chrono::time_point<_Clock, _Duration>& __t)
148            : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock_until(__t)) {}
149    template <class _Rep, class _Period>
150    _LIBCPP_INLINE_VISIBILITY
151        unique_lock(mutex_type& __m, const chrono::duration<_Rep, _Period>& __d)
152            : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock_for(__d)) {}
153    _LIBCPP_INLINE_VISIBILITY
154    ~unique_lock()
155    {
156        if (__owns_)
157            __m_->unlock();
158    }
159
160private:
161    unique_lock(unique_lock const&); // = delete;
162    unique_lock& operator=(unique_lock const&); // = delete;
163
164public:
165#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
166    _LIBCPP_INLINE_VISIBILITY
167    unique_lock(unique_lock&& __u) _NOEXCEPT
168        : __m_(__u.__m_), __owns_(__u.__owns_)
169        {__u.__m_ = nullptr; __u.__owns_ = false;}
170    _LIBCPP_INLINE_VISIBILITY
171    unique_lock& operator=(unique_lock&& __u) _NOEXCEPT
172        {
173            if (__owns_)
174                __m_->unlock();
175            __m_ = __u.__m_;
176            __owns_ = __u.__owns_;
177            __u.__m_ = nullptr;
178            __u.__owns_ = false;
179            return *this;
180        }
181
182#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
183
184    void lock();
185    bool try_lock();
186
187    template <class _Rep, class _Period>
188        bool try_lock_for(const chrono::duration<_Rep, _Period>& __d);
189    template <class _Clock, class _Duration>
190        bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
191
192    void unlock();
193
194    _LIBCPP_INLINE_VISIBILITY
195    void swap(unique_lock& __u) _NOEXCEPT
196    {
197        _VSTD::swap(__m_, __u.__m_);
198        _VSTD::swap(__owns_, __u.__owns_);
199    }
200    _LIBCPP_INLINE_VISIBILITY
201    mutex_type* release() _NOEXCEPT
202    {
203        mutex_type* __m = __m_;
204        __m_ = nullptr;
205        __owns_ = false;
206        return __m;
207    }
208
209    _LIBCPP_INLINE_VISIBILITY
210    bool owns_lock() const _NOEXCEPT {return __owns_;}
211    _LIBCPP_INLINE_VISIBILITY
212    _LIBCPP_EXPLICIT
213        operator bool () const _NOEXCEPT {return __owns_;}
214    _LIBCPP_INLINE_VISIBILITY
215    mutex_type* mutex() const _NOEXCEPT {return __m_;}
216};
217
218template <class _Mutex>
219void
220unique_lock<_Mutex>::lock()
221{
222    if (__m_ == nullptr)
223        __throw_system_error(EPERM, "unique_lock::lock: references null mutex");
224    if (__owns_)
225        __throw_system_error(EDEADLK, "unique_lock::lock: already locked");
226    __m_->lock();
227    __owns_ = true;
228}
229
230template <class _Mutex>
231bool
232unique_lock<_Mutex>::try_lock()
233{
234    if (__m_ == nullptr)
235        __throw_system_error(EPERM, "unique_lock::try_lock: references null mutex");
236    if (__owns_)
237        __throw_system_error(EDEADLK, "unique_lock::try_lock: already locked");
238    __owns_ = __m_->try_lock();
239    return __owns_;
240}
241
242template <class _Mutex>
243template <class _Rep, class _Period>
244bool
245unique_lock<_Mutex>::try_lock_for(const chrono::duration<_Rep, _Period>& __d)
246{
247    if (__m_ == nullptr)
248        __throw_system_error(EPERM, "unique_lock::try_lock_for: references null mutex");
249    if (__owns_)
250        __throw_system_error(EDEADLK, "unique_lock::try_lock_for: already locked");
251    __owns_ = __m_->try_lock_for(__d);
252    return __owns_;
253}
254
255template <class _Mutex>
256template <class _Clock, class _Duration>
257bool
258unique_lock<_Mutex>::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
259{
260    if (__m_ == nullptr)
261        __throw_system_error(EPERM, "unique_lock::try_lock_until: references null mutex");
262    if (__owns_)
263        __throw_system_error(EDEADLK, "unique_lock::try_lock_until: already locked");
264    __owns_ = __m_->try_lock_until(__t);
265    return __owns_;
266}
267
268template <class _Mutex>
269void
270unique_lock<_Mutex>::unlock()
271{
272    if (!__owns_)
273        __throw_system_error(EPERM, "unique_lock::unlock: not locked");
274    __m_->unlock();
275    __owns_ = false;
276}
277
278template <class _Mutex>
279inline _LIBCPP_INLINE_VISIBILITY
280void
281swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) _NOEXCEPT
282    {__x.swap(__y);}
283
284//enum class cv_status
285_LIBCPP_DECLARE_STRONG_ENUM(cv_status)
286{
287    no_timeout,
288    timeout
289};
290_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(cv_status)
291
292class _LIBCPP_TYPE_VIS condition_variable
293{
294#ifndef _LIBCPP_HAS_NO_CONSTEXPR
295    __libcpp_condvar_t __cv_ = _LIBCPP_CONDVAR_INITIALIZER;
296#else
297    __libcpp_condvar_t __cv_;
298#endif
299
300public:
301    _LIBCPP_INLINE_VISIBILITY
302#ifndef _LIBCPP_HAS_NO_CONSTEXPR
303    constexpr condition_variable() _NOEXCEPT = default;
304#else
305    condition_variable() _NOEXCEPT {__cv_ = (__libcpp_condvar_t)_LIBCPP_CONDVAR_INITIALIZER;}
306#endif
307    ~condition_variable();
308
309private:
310    condition_variable(const condition_variable&); // = delete;
311    condition_variable& operator=(const condition_variable&); // = delete;
312
313public:
314    void notify_one() _NOEXCEPT;
315    void notify_all() _NOEXCEPT;
316
317    void wait(unique_lock<mutex>& __lk) _NOEXCEPT;
318    template <class _Predicate>
319        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
320        void wait(unique_lock<mutex>& __lk, _Predicate __pred);
321
322    template <class _Clock, class _Duration>
323        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
324        cv_status
325        wait_until(unique_lock<mutex>& __lk,
326                   const chrono::time_point<_Clock, _Duration>& __t);
327
328    template <class _Clock, class _Duration, class _Predicate>
329        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
330        bool
331        wait_until(unique_lock<mutex>& __lk,
332                   const chrono::time_point<_Clock, _Duration>& __t,
333                   _Predicate __pred);
334
335    template <class _Rep, class _Period>
336        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
337        cv_status
338        wait_for(unique_lock<mutex>& __lk,
339                 const chrono::duration<_Rep, _Period>& __d);
340
341    template <class _Rep, class _Period, class _Predicate>
342        bool
343        _LIBCPP_INLINE_VISIBILITY
344        wait_for(unique_lock<mutex>& __lk,
345                 const chrono::duration<_Rep, _Period>& __d,
346                 _Predicate __pred);
347
348    typedef __libcpp_condvar_t* native_handle_type;
349    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__cv_;}
350
351private:
352    void __do_timed_wait(unique_lock<mutex>& __lk,
353       chrono::time_point<chrono::system_clock, chrono::nanoseconds>) _NOEXCEPT;
354};
355#endif // !_LIBCPP_HAS_NO_THREADS
356
357template <class _To, class _Rep, class _Period>
358inline _LIBCPP_INLINE_VISIBILITY
359typename enable_if
360<
361    chrono::__is_duration<_To>::value,
362    _To
363>::type
364__ceil(chrono::duration<_Rep, _Period> __d)
365{
366    using namespace chrono;
367    _To __r = duration_cast<_To>(__d);
368    if (__r < __d)
369        ++__r;
370    return __r;
371}
372
373#ifndef _LIBCPP_HAS_NO_THREADS
374template <class _Predicate>
375void
376condition_variable::wait(unique_lock<mutex>& __lk, _Predicate __pred)
377{
378    while (!__pred())
379        wait(__lk);
380}
381
382template <class _Clock, class _Duration>
383cv_status
384condition_variable::wait_until(unique_lock<mutex>& __lk,
385                               const chrono::time_point<_Clock, _Duration>& __t)
386{
387    using namespace chrono;
388    wait_for(__lk, __t - _Clock::now());
389    return _Clock::now() < __t ? cv_status::no_timeout : cv_status::timeout;
390}
391
392template <class _Clock, class _Duration, class _Predicate>
393bool
394condition_variable::wait_until(unique_lock<mutex>& __lk,
395                   const chrono::time_point<_Clock, _Duration>& __t,
396                   _Predicate __pred)
397{
398    while (!__pred())
399    {
400        if (wait_until(__lk, __t) == cv_status::timeout)
401            return __pred();
402    }
403    return true;
404}
405
406template <class _Rep, class _Period>
407cv_status
408condition_variable::wait_for(unique_lock<mutex>& __lk,
409                             const chrono::duration<_Rep, _Period>& __d)
410{
411    using namespace chrono;
412    if (__d <= __d.zero())
413        return cv_status::timeout;
414    typedef time_point<system_clock, duration<long double, nano> > __sys_tpf;
415    typedef time_point<system_clock, nanoseconds> __sys_tpi;
416    __sys_tpf _Max = __sys_tpi::max();
417    steady_clock::time_point __c_now = steady_clock::now();
418    system_clock::time_point __s_now = system_clock::now();
419    if (_Max - __d > __s_now)
420        __do_timed_wait(__lk, __s_now + __ceil<nanoseconds>(__d));
421    else
422        __do_timed_wait(__lk, __sys_tpi::max());
423    return steady_clock::now() - __c_now < __d ? cv_status::no_timeout :
424                                                 cv_status::timeout;
425}
426
427template <class _Rep, class _Period, class _Predicate>
428inline
429bool
430condition_variable::wait_for(unique_lock<mutex>& __lk,
431                             const chrono::duration<_Rep, _Period>& __d,
432                             _Predicate __pred)
433{
434    return wait_until(__lk, chrono::steady_clock::now() + __d,
435                      _VSTD::move(__pred));
436}
437
438#endif // !_LIBCPP_HAS_NO_THREADS
439
440_LIBCPP_END_NAMESPACE_STD
441
442#endif  // _LIBCPP___MUTEX_BASE
443