__mutex_base revision 262801 
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
25class _LIBCPP_TYPE_VIS mutex
26{
27    pthread_mutex_t __m_;
28
29public:
30    _LIBCPP_INLINE_VISIBILITY
31#ifndef _LIBCPP_HAS_NO_CONSTEXPR
32     constexpr mutex() _NOEXCEPT : __m_(PTHREAD_MUTEX_INITIALIZER) {}
33#else
34     mutex() _NOEXCEPT {__m_ = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;}
35#endif
36     ~mutex();
37
38private:
39    mutex(const mutex&);// = delete;
40    mutex& operator=(const mutex&);// = delete;
41
42public:
43    void lock();
44    bool try_lock() _NOEXCEPT;
45    void unlock() _NOEXCEPT;
46
47    typedef pthread_mutex_t* native_handle_type;
48    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__m_;}
49};
50
51struct _LIBCPP_TYPE_VIS defer_lock_t {};
52struct _LIBCPP_TYPE_VIS try_to_lock_t {};
53struct _LIBCPP_TYPE_VIS adopt_lock_t {};
54
55#if defined(_LIBCPP_HAS_NO_CONSTEXPR) || defined(_LIBCPP_BUILDING_MUTEX)
56
57extern const defer_lock_t  defer_lock;
58extern const try_to_lock_t try_to_lock;
59extern const adopt_lock_t  adopt_lock;
60
61#else
62
63constexpr defer_lock_t  defer_lock  = defer_lock_t();
64constexpr try_to_lock_t try_to_lock = try_to_lock_t();
65constexpr adopt_lock_t  adopt_lock  = adopt_lock_t();
66
67#endif
68
69template <class _Mutex>
70class _LIBCPP_TYPE_VIS_ONLY lock_guard
71{
72public:
73    typedef _Mutex mutex_type;
74
75private:
76    mutex_type& __m_;
77public:
78
79    _LIBCPP_INLINE_VISIBILITY
80    explicit lock_guard(mutex_type& __m)
81        : __m_(__m) {__m_.lock();}
82    _LIBCPP_INLINE_VISIBILITY
83    lock_guard(mutex_type& __m, adopt_lock_t)
84        : __m_(__m) {}
85    _LIBCPP_INLINE_VISIBILITY
86    ~lock_guard() {__m_.unlock();}
87
88private:
89    lock_guard(lock_guard const&);// = delete;
90    lock_guard& operator=(lock_guard const&);// = delete;
91};
92
93template <class _Mutex>
94class _LIBCPP_TYPE_VIS_ONLY unique_lock
95{
96public:
97    typedef _Mutex mutex_type;
98
99private:
100    mutex_type* __m_;
101    bool __owns_;
102
103public:
104    _LIBCPP_INLINE_VISIBILITY
105    unique_lock() _NOEXCEPT : __m_(nullptr), __owns_(false) {}
106    _LIBCPP_INLINE_VISIBILITY
107    explicit unique_lock(mutex_type& __m)
108        : __m_(&__m), __owns_(true) {__m_->lock();}
109    _LIBCPP_INLINE_VISIBILITY
110    unique_lock(mutex_type& __m, defer_lock_t) _NOEXCEPT
111        : __m_(&__m), __owns_(false) {}
112    _LIBCPP_INLINE_VISIBILITY
113    unique_lock(mutex_type& __m, try_to_lock_t)
114        : __m_(&__m), __owns_(__m.try_lock()) {}
115    _LIBCPP_INLINE_VISIBILITY
116    unique_lock(mutex_type& __m, adopt_lock_t)
117        : __m_(&__m), __owns_(true) {}
118    template <class _Clock, class _Duration>
119    _LIBCPP_INLINE_VISIBILITY
120        unique_lock(mutex_type& __m, const chrono::time_point<_Clock, _Duration>& __t)
121            : __m_(&__m), __owns_(__m.try_lock_until(__t)) {}
122    template <class _Rep, class _Period>
123    _LIBCPP_INLINE_VISIBILITY
124        unique_lock(mutex_type& __m, const chrono::duration<_Rep, _Period>& __d)
125            : __m_(&__m), __owns_(__m.try_lock_for(__d)) {}
126    _LIBCPP_INLINE_VISIBILITY
127    ~unique_lock()
128    {
129        if (__owns_)
130            __m_->unlock();
131    }
132
133private:
134    unique_lock(unique_lock const&); // = delete;
135    unique_lock& operator=(unique_lock const&); // = delete;
136
137public:
138#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
139    _LIBCPP_INLINE_VISIBILITY
140    unique_lock(unique_lock&& __u) _NOEXCEPT
141        : __m_(__u.__m_), __owns_(__u.__owns_)
142        {__u.__m_ = nullptr; __u.__owns_ = false;}
143    _LIBCPP_INLINE_VISIBILITY
144    unique_lock& operator=(unique_lock&& __u) _NOEXCEPT
145        {
146            if (__owns_)
147                __m_->unlock();
148            __m_ = __u.__m_;
149            __owns_ = __u.__owns_;
150            __u.__m_ = nullptr;
151            __u.__owns_ = false;
152            return *this;
153        }
154
155#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
156
157    void lock();
158    bool try_lock();
159
160    template <class _Rep, class _Period>
161        bool try_lock_for(const chrono::duration<_Rep, _Period>& __d);
162    template <class _Clock, class _Duration>
163        bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
164
165    void unlock();
166
167    _LIBCPP_INLINE_VISIBILITY
168    void swap(unique_lock& __u) _NOEXCEPT
169    {
170        _VSTD::swap(__m_, __u.__m_);
171        _VSTD::swap(__owns_, __u.__owns_);
172    }
173    _LIBCPP_INLINE_VISIBILITY
174    mutex_type* release() _NOEXCEPT
175    {
176        mutex_type* __m = __m_;
177        __m_ = nullptr;
178        __owns_ = false;
179        return __m;
180    }
181
182    _LIBCPP_INLINE_VISIBILITY
183    bool owns_lock() const _NOEXCEPT {return __owns_;}
184    _LIBCPP_INLINE_VISIBILITY
185    _LIBCPP_EXPLICIT
186        operator bool () const _NOEXCEPT {return __owns_;}
187    _LIBCPP_INLINE_VISIBILITY
188    mutex_type* mutex() const _NOEXCEPT {return __m_;}
189};
190
191template <class _Mutex>
192void
193unique_lock<_Mutex>::lock()
194{
195    if (__m_ == nullptr)
196        __throw_system_error(EPERM, "unique_lock::lock: references null mutex");
197    if (__owns_)
198        __throw_system_error(EDEADLK, "unique_lock::lock: already locked");
199    __m_->lock();
200    __owns_ = true;
201}
202
203template <class _Mutex>
204bool
205unique_lock<_Mutex>::try_lock()
206{
207    if (__m_ == nullptr)
208        __throw_system_error(EPERM, "unique_lock::try_lock: references null mutex");
209    if (__owns_)
210        __throw_system_error(EDEADLK, "unique_lock::try_lock: already locked");
211    __owns_ = __m_->try_lock();
212    return __owns_;
213}
214
215template <class _Mutex>
216template <class _Rep, class _Period>
217bool
218unique_lock<_Mutex>::try_lock_for(const chrono::duration<_Rep, _Period>& __d)
219{
220    if (__m_ == nullptr)
221        __throw_system_error(EPERM, "unique_lock::try_lock_for: references null mutex");
222    if (__owns_)
223        __throw_system_error(EDEADLK, "unique_lock::try_lock_for: already locked");
224    __owns_ = __m_->try_lock_for(__d);
225    return __owns_;
226}
227
228template <class _Mutex>
229template <class _Clock, class _Duration>
230bool
231unique_lock<_Mutex>::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
232{
233    if (__m_ == nullptr)
234        __throw_system_error(EPERM, "unique_lock::try_lock_until: references null mutex");
235    if (__owns_)
236        __throw_system_error(EDEADLK, "unique_lock::try_lock_until: already locked");
237    __owns_ = __m_->try_lock_until(__t);
238    return __owns_;
239}
240
241template <class _Mutex>
242void
243unique_lock<_Mutex>::unlock()
244{
245    if (!__owns_)
246        __throw_system_error(EPERM, "unique_lock::unlock: not locked");
247    __m_->unlock();
248    __owns_ = false;
249}
250
251template <class _Mutex>
252inline _LIBCPP_INLINE_VISIBILITY
253void
254swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) _NOEXCEPT
255    {__x.swap(__y);}
256
257struct _LIBCPP_TYPE_VIS cv_status
258{
259    enum __lx {
260        no_timeout,
261        timeout
262    };
263
264    __lx __v_;
265
266    _LIBCPP_INLINE_VISIBILITY cv_status(__lx __v) : __v_(__v) {}
267    _LIBCPP_INLINE_VISIBILITY operator int() const {return __v_;}
268
269};
270
271class _LIBCPP_TYPE_VIS condition_variable
272{
273    pthread_cond_t __cv_;
274public:
275    _LIBCPP_INLINE_VISIBILITY
276#ifndef _LIBCPP_HAS_NO_CONSTEXPR
277    constexpr condition_variable() : __cv_(PTHREAD_COND_INITIALIZER) {}
278#else
279    condition_variable() {__cv_ = (pthread_cond_t)PTHREAD_COND_INITIALIZER;}
280#endif
281    ~condition_variable();
282
283private:
284    condition_variable(const condition_variable&); // = delete;
285    condition_variable& operator=(const condition_variable&); // = delete;
286
287public:
288    void notify_one() _NOEXCEPT;
289    void notify_all() _NOEXCEPT;
290
291    void wait(unique_lock<mutex>& __lk);
292    template <class _Predicate>
293        void wait(unique_lock<mutex>& __lk, _Predicate __pred);
294
295    template <class _Clock, class _Duration>
296        cv_status
297        wait_until(unique_lock<mutex>& __lk,
298                   const chrono::time_point<_Clock, _Duration>& __t);
299
300    template <class _Clock, class _Duration, class _Predicate>
301        bool
302        wait_until(unique_lock<mutex>& __lk,
303                   const chrono::time_point<_Clock, _Duration>& __t,
304                   _Predicate __pred);
305
306    template <class _Rep, class _Period>
307        cv_status
308        wait_for(unique_lock<mutex>& __lk,
309                 const chrono::duration<_Rep, _Period>& __d);
310
311    template <class _Rep, class _Period, class _Predicate>
312        bool
313        wait_for(unique_lock<mutex>& __lk,
314                 const chrono::duration<_Rep, _Period>& __d,
315                 _Predicate __pred);
316
317    typedef pthread_cond_t* native_handle_type;
318    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__cv_;}
319
320private:
321    void __do_timed_wait(unique_lock<mutex>& __lk,
322                 chrono::time_point<chrono::system_clock, chrono::nanoseconds>);
323};
324
325template <class _To, class _Rep, class _Period>
326inline _LIBCPP_INLINE_VISIBILITY
327typename enable_if
328<
329    chrono::__is_duration<_To>::value,
330    _To
331>::type
332__ceil(chrono::duration<_Rep, _Period> __d)
333{
334    using namespace chrono;
335    _To __r = duration_cast<_To>(__d);
336    if (__r < __d)
337        ++__r;
338    return __r;
339}
340
341template <class _Predicate>
342void
343condition_variable::wait(unique_lock<mutex>& __lk, _Predicate __pred)
344{
345    while (!__pred())
346        wait(__lk);
347}
348
349template <class _Clock, class _Duration>
350cv_status
351condition_variable::wait_until(unique_lock<mutex>& __lk,
352                               const chrono::time_point<_Clock, _Duration>& __t)
353{
354    using namespace chrono;
355    wait_for(__lk, __t - _Clock::now());
356    return _Clock::now() < __t ? cv_status::no_timeout : cv_status::timeout;
357}
358
359template <class _Clock, class _Duration, class _Predicate>
360bool
361condition_variable::wait_until(unique_lock<mutex>& __lk,
362                   const chrono::time_point<_Clock, _Duration>& __t,
363                   _Predicate __pred)
364{
365    while (!__pred())
366    {
367        if (wait_until(__lk, __t) == cv_status::timeout)
368            return __pred();
369    }
370    return true;
371}
372
373template <class _Rep, class _Period>
374cv_status
375condition_variable::wait_for(unique_lock<mutex>& __lk,
376                             const chrono::duration<_Rep, _Period>& __d)
377{
378    using namespace chrono;
379    if (__d <= __d.zero())
380        return cv_status::timeout;
381    typedef time_point<system_clock, duration<long double, nano> > __sys_tpf;
382    typedef time_point<system_clock, nanoseconds> __sys_tpi;
383    __sys_tpf _Max = __sys_tpi::max();
384    system_clock::time_point __s_now = system_clock::now();
385    steady_clock::time_point __c_now = steady_clock::now();
386    if (_Max - __d > __s_now)
387        __do_timed_wait(__lk, __s_now + __ceil<nanoseconds>(__d));
388    else
389        __do_timed_wait(__lk, __sys_tpi::max());
390    return steady_clock::now() - __c_now < __d ? cv_status::no_timeout :
391                                                 cv_status::timeout;
392}
393
394template <class _Rep, class _Period, class _Predicate>
395inline _LIBCPP_INLINE_VISIBILITY
396bool
397condition_variable::wait_for(unique_lock<mutex>& __lk,
398                             const chrono::duration<_Rep, _Period>& __d,
399                             _Predicate __pred)
400{
401    return wait_until(__lk, chrono::steady_clock::now() + __d,
402                      _VSTD::move(__pred));
403}
404
405_LIBCPP_END_NAMESPACE_STD
406
407#endif  // _LIBCPP___MUTEX_BASE
408