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