__mutex_base revision 278724 
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 <pthread.h>
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
27class _LIBCPP_TYPE_VIS mutex
28{
29    pthread_mutex_t __m_;
30
31public:
32    _LIBCPP_INLINE_VISIBILITY
33#ifndef _LIBCPP_HAS_NO_CONSTEXPR
34     constexpr mutex() _NOEXCEPT : __m_(PTHREAD_MUTEX_INITIALIZER) {}
35#else
36     mutex() _NOEXCEPT {__m_ = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;}
37#endif
38     ~mutex();
39
40private:
41    mutex(const mutex&);// = delete;
42    mutex& operator=(const mutex&);// = delete;
43
44public:
45    void lock();
46    bool try_lock() _NOEXCEPT;
47    void unlock() _NOEXCEPT;
48
49    typedef pthread_mutex_t* native_handle_type;
50    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__m_;}
51};
52
53struct _LIBCPP_TYPE_VIS defer_lock_t {};
54struct _LIBCPP_TYPE_VIS try_to_lock_t {};
55struct _LIBCPP_TYPE_VIS adopt_lock_t {};
56
57#if defined(_LIBCPP_HAS_NO_CONSTEXPR) || defined(_LIBCPP_BUILDING_MUTEX)
58
59extern const defer_lock_t  defer_lock;
60extern const try_to_lock_t try_to_lock;
61extern const adopt_lock_t  adopt_lock;
62
63#else
64
65constexpr defer_lock_t  defer_lock  = defer_lock_t();
66constexpr try_to_lock_t try_to_lock = try_to_lock_t();
67constexpr adopt_lock_t  adopt_lock  = adopt_lock_t();
68
69#endif
70
71template <class _Mutex>
72class _LIBCPP_TYPE_VIS_ONLY lock_guard
73{
74public:
75    typedef _Mutex mutex_type;
76
77private:
78    mutex_type& __m_;
79public:
80
81    _LIBCPP_INLINE_VISIBILITY
82    explicit lock_guard(mutex_type& __m)
83        : __m_(__m) {__m_.lock();}
84    _LIBCPP_INLINE_VISIBILITY
85    lock_guard(mutex_type& __m, adopt_lock_t)
86        : __m_(__m) {}
87    _LIBCPP_INLINE_VISIBILITY
88    ~lock_guard() {__m_.unlock();}
89
90private:
91    lock_guard(lock_guard const&);// = delete;
92    lock_guard& operator=(lock_guard const&);// = delete;
93};
94
95template <class _Mutex>
96class _LIBCPP_TYPE_VIS_ONLY unique_lock
97{
98public:
99    typedef _Mutex mutex_type;
100
101private:
102    mutex_type* __m_;
103    bool __owns_;
104
105public:
106    _LIBCPP_INLINE_VISIBILITY
107    unique_lock() _NOEXCEPT : __m_(nullptr), __owns_(false) {}
108    _LIBCPP_INLINE_VISIBILITY
109    explicit unique_lock(mutex_type& __m)
110        : __m_(&__m), __owns_(true) {__m_->lock();}
111    _LIBCPP_INLINE_VISIBILITY
112    unique_lock(mutex_type& __m, defer_lock_t) _NOEXCEPT
113        : __m_(&__m), __owns_(false) {}
114    _LIBCPP_INLINE_VISIBILITY
115    unique_lock(mutex_type& __m, try_to_lock_t)
116        : __m_(&__m), __owns_(__m.try_lock()) {}
117    _LIBCPP_INLINE_VISIBILITY
118    unique_lock(mutex_type& __m, adopt_lock_t)
119        : __m_(&__m), __owns_(true) {}
120    template <class _Clock, class _Duration>
121    _LIBCPP_INLINE_VISIBILITY
122        unique_lock(mutex_type& __m, const chrono::time_point<_Clock, _Duration>& __t)
123            : __m_(&__m), __owns_(__m.try_lock_until(__t)) {}
124    template <class _Rep, class _Period>
125    _LIBCPP_INLINE_VISIBILITY
126        unique_lock(mutex_type& __m, const chrono::duration<_Rep, _Period>& __d)
127            : __m_(&__m), __owns_(__m.try_lock_for(__d)) {}
128    _LIBCPP_INLINE_VISIBILITY
129    ~unique_lock()
130    {
131        if (__owns_)
132            __m_->unlock();
133    }
134
135private:
136    unique_lock(unique_lock const&); // = delete;
137    unique_lock& operator=(unique_lock const&); // = delete;
138
139public:
140#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
141    _LIBCPP_INLINE_VISIBILITY
142    unique_lock(unique_lock&& __u) _NOEXCEPT
143        : __m_(__u.__m_), __owns_(__u.__owns_)
144        {__u.__m_ = nullptr; __u.__owns_ = false;}
145    _LIBCPP_INLINE_VISIBILITY
146    unique_lock& operator=(unique_lock&& __u) _NOEXCEPT
147        {
148            if (__owns_)
149                __m_->unlock();
150            __m_ = __u.__m_;
151            __owns_ = __u.__owns_;
152            __u.__m_ = nullptr;
153            __u.__owns_ = false;
154            return *this;
155        }
156
157#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
158
159    void lock();
160    bool try_lock();
161
162    template <class _Rep, class _Period>
163        bool try_lock_for(const chrono::duration<_Rep, _Period>& __d);
164    template <class _Clock, class _Duration>
165        bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
166
167    void unlock();
168
169    _LIBCPP_INLINE_VISIBILITY
170    void swap(unique_lock& __u) _NOEXCEPT
171    {
172        _VSTD::swap(__m_, __u.__m_);
173        _VSTD::swap(__owns_, __u.__owns_);
174    }
175    _LIBCPP_INLINE_VISIBILITY
176    mutex_type* release() _NOEXCEPT
177    {
178        mutex_type* __m = __m_;
179        __m_ = nullptr;
180        __owns_ = false;
181        return __m;
182    }
183
184    _LIBCPP_INLINE_VISIBILITY
185    bool owns_lock() const _NOEXCEPT {return __owns_;}
186    _LIBCPP_INLINE_VISIBILITY
187    _LIBCPP_EXPLICIT
188        operator bool () const _NOEXCEPT {return __owns_;}
189    _LIBCPP_INLINE_VISIBILITY
190    mutex_type* mutex() const _NOEXCEPT {return __m_;}
191};
192
193template <class _Mutex>
194void
195unique_lock<_Mutex>::lock()
196{
197    if (__m_ == nullptr)
198        __throw_system_error(EPERM, "unique_lock::lock: references null mutex");
199    if (__owns_)
200        __throw_system_error(EDEADLK, "unique_lock::lock: already locked");
201    __m_->lock();
202    __owns_ = true;
203}
204
205template <class _Mutex>
206bool
207unique_lock<_Mutex>::try_lock()
208{
209    if (__m_ == nullptr)
210        __throw_system_error(EPERM, "unique_lock::try_lock: references null mutex");
211    if (__owns_)
212        __throw_system_error(EDEADLK, "unique_lock::try_lock: already locked");
213    __owns_ = __m_->try_lock();
214    return __owns_;
215}
216
217template <class _Mutex>
218template <class _Rep, class _Period>
219bool
220unique_lock<_Mutex>::try_lock_for(const chrono::duration<_Rep, _Period>& __d)
221{
222    if (__m_ == nullptr)
223        __throw_system_error(EPERM, "unique_lock::try_lock_for: references null mutex");
224    if (__owns_)
225        __throw_system_error(EDEADLK, "unique_lock::try_lock_for: already locked");
226    __owns_ = __m_->try_lock_for(__d);
227    return __owns_;
228}
229
230template <class _Mutex>
231template <class _Clock, class _Duration>
232bool
233unique_lock<_Mutex>::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
234{
235    if (__m_ == nullptr)
236        __throw_system_error(EPERM, "unique_lock::try_lock_until: references null mutex");
237    if (__owns_)
238        __throw_system_error(EDEADLK, "unique_lock::try_lock_until: already locked");
239    __owns_ = __m_->try_lock_until(__t);
240    return __owns_;
241}
242
243template <class _Mutex>
244void
245unique_lock<_Mutex>::unlock()
246{
247    if (!__owns_)
248        __throw_system_error(EPERM, "unique_lock::unlock: not locked");
249    __m_->unlock();
250    __owns_ = false;
251}
252
253template <class _Mutex>
254inline _LIBCPP_INLINE_VISIBILITY
255void
256swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) _NOEXCEPT
257    {__x.swap(__y);}
258
259//enum class cv_status
260_LIBCPP_DECLARE_STRONG_ENUM(cv_status)
261{
262    no_timeout,
263    timeout
264};
265_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(cv_status)
266
267class _LIBCPP_TYPE_VIS condition_variable
268{
269    pthread_cond_t __cv_;
270public:
271    _LIBCPP_INLINE_VISIBILITY
272#ifndef _LIBCPP_HAS_NO_CONSTEXPR
273    constexpr condition_variable() : __cv_(PTHREAD_COND_INITIALIZER) {}
274#else
275    condition_variable() {__cv_ = (pthread_cond_t)PTHREAD_COND_INITIALIZER;}
276#endif
277    ~condition_variable();
278
279private:
280    condition_variable(const condition_variable&); // = delete;
281    condition_variable& operator=(const condition_variable&); // = delete;
282
283public:
284    void notify_one() _NOEXCEPT;
285    void notify_all() _NOEXCEPT;
286
287    void wait(unique_lock<mutex>& __lk) _NOEXCEPT;
288    template <class _Predicate>
289        void wait(unique_lock<mutex>& __lk, _Predicate __pred);
290
291    template <class _Clock, class _Duration>
292        cv_status
293        wait_until(unique_lock<mutex>& __lk,
294                   const chrono::time_point<_Clock, _Duration>& __t);
295
296    template <class _Clock, class _Duration, class _Predicate>
297        bool
298        wait_until(unique_lock<mutex>& __lk,
299                   const chrono::time_point<_Clock, _Duration>& __t,
300                   _Predicate __pred);
301
302    template <class _Rep, class _Period>
303        cv_status
304        wait_for(unique_lock<mutex>& __lk,
305                 const chrono::duration<_Rep, _Period>& __d);
306
307    template <class _Rep, class _Period, class _Predicate>
308        bool
309        wait_for(unique_lock<mutex>& __lk,
310                 const chrono::duration<_Rep, _Period>& __d,
311                 _Predicate __pred);
312
313    typedef pthread_cond_t* native_handle_type;
314    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__cv_;}
315
316private:
317    void __do_timed_wait(unique_lock<mutex>& __lk,
318       chrono::time_point<chrono::system_clock, chrono::nanoseconds>) _NOEXCEPT;
319};
320#endif // !_LIBCPP_HAS_NO_THREADS
321
322template <class _To, class _Rep, class _Period>
323inline _LIBCPP_INLINE_VISIBILITY
324typename enable_if
325<
326    chrono::__is_duration<_To>::value,
327    _To
328>::type
329__ceil(chrono::duration<_Rep, _Period> __d)
330{
331    using namespace chrono;
332    _To __r = duration_cast<_To>(__d);
333    if (__r < __d)
334        ++__r;
335    return __r;
336}
337
338#ifndef _LIBCPP_HAS_NO_THREADS
339template <class _Predicate>
340void
341condition_variable::wait(unique_lock<mutex>& __lk, _Predicate __pred)
342{
343    while (!__pred())
344        wait(__lk);
345}
346
347template <class _Clock, class _Duration>
348cv_status
349condition_variable::wait_until(unique_lock<mutex>& __lk,
350                               const chrono::time_point<_Clock, _Duration>& __t)
351{
352    using namespace chrono;
353    wait_for(__lk, __t - _Clock::now());
354    return _Clock::now() < __t ? cv_status::no_timeout : cv_status::timeout;
355}
356
357template <class _Clock, class _Duration, class _Predicate>
358bool
359condition_variable::wait_until(unique_lock<mutex>& __lk,
360                   const chrono::time_point<_Clock, _Duration>& __t,
361                   _Predicate __pred)
362{
363    while (!__pred())
364    {
365        if (wait_until(__lk, __t) == cv_status::timeout)
366            return __pred();
367    }
368    return true;
369}
370
371template <class _Rep, class _Period>
372cv_status
373condition_variable::wait_for(unique_lock<mutex>& __lk,
374                             const chrono::duration<_Rep, _Period>& __d)
375{
376    using namespace chrono;
377    if (__d <= __d.zero())
378        return cv_status::timeout;
379    typedef time_point<system_clock, duration<long double, nano> > __sys_tpf;
380    typedef time_point<system_clock, nanoseconds> __sys_tpi;
381    __sys_tpf _Max = __sys_tpi::max();
382    system_clock::time_point __s_now = system_clock::now();
383    steady_clock::time_point __c_now = steady_clock::now();
384    if (_Max - __d > __s_now)
385        __do_timed_wait(__lk, __s_now + __ceil<nanoseconds>(__d));
386    else
387        __do_timed_wait(__lk, __sys_tpi::max());
388    return steady_clock::now() - __c_now < __d ? cv_status::no_timeout :
389                                                 cv_status::timeout;
390}
391
392template <class _Rep, class _Period, class _Predicate>
393inline _LIBCPP_INLINE_VISIBILITY
394bool
395condition_variable::wait_for(unique_lock<mutex>& __lk,
396                             const chrono::duration<_Rep, _Period>& __d,
397                             _Predicate __pred)
398{
399    return wait_until(__lk, chrono::steady_clock::now() + __d,
400                      _VSTD::move(__pred));
401}
402
403#endif // !_LIBCPP_HAS_NO_THREADS
404
405_LIBCPP_END_NAMESPACE_STD
406
407#endif  // _LIBCPP___MUTEX_BASE
408