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#ifdef _LIBCPP_SHARED_LOCK
24
25namespace ting {
26template <class _Mutex> class shared_lock;
27template <class _Mutex> class upgrade_lock;
28}
29
30#endif  // _LIBCPP_SHARED_LOCK
31
32
33_LIBCPP_BEGIN_NAMESPACE_STD
34
35class _LIBCPP_VISIBLE mutex
36{
37    pthread_mutex_t __m_;
38
39public:
40    _LIBCPP_INLINE_VISIBILITY
41#ifndef _LIBCPP_HAS_NO_CONSTEXPR
42     constexpr mutex() _NOEXCEPT : __m_ PTHREAD_MUTEX_INITIALIZER {}
43#else
44     mutex() _NOEXCEPT {__m_ = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;}
45#endif
46     ~mutex();
47
48private:
49    mutex(const mutex&);// = delete;
50    mutex& operator=(const mutex&);// = delete;
51
52public:
53    void lock();
54    bool try_lock() _NOEXCEPT;
55    void unlock() _NOEXCEPT;
56
57    typedef pthread_mutex_t* native_handle_type;
58    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__m_;}
59};
60
61struct _LIBCPP_VISIBLE defer_lock_t {};
62struct _LIBCPP_VISIBLE try_to_lock_t {};
63struct _LIBCPP_VISIBLE adopt_lock_t {};
64
65#if defined(_LIBCPP_HAS_NO_CONSTEXPR) || defined(_LIBCPP_BUILDING_MUTEX)
66
67extern const defer_lock_t  defer_lock;
68extern const try_to_lock_t try_to_lock;
69extern const adopt_lock_t  adopt_lock;
70
71#else
72
73constexpr defer_lock_t  defer_lock  = defer_lock_t();
74constexpr try_to_lock_t try_to_lock = try_to_lock_t();
75constexpr adopt_lock_t  adopt_lock  = adopt_lock_t();
76
77#endif
78
79template <class _Mutex>
80class _LIBCPP_VISIBLE lock_guard
81{
82public:
83    typedef _Mutex mutex_type;
84
85private:
86    mutex_type& __m_;
87public:
88
89    _LIBCPP_INLINE_VISIBILITY
90    explicit lock_guard(mutex_type& __m)
91        : __m_(__m) {__m_.lock();}
92    _LIBCPP_INLINE_VISIBILITY
93    lock_guard(mutex_type& __m, adopt_lock_t)
94        : __m_(__m) {}
95    _LIBCPP_INLINE_VISIBILITY
96    ~lock_guard() {__m_.unlock();}
97
98private:
99    lock_guard(lock_guard const&);// = delete;
100    lock_guard& operator=(lock_guard const&);// = delete;
101};
102
103template <class _Mutex>
104class _LIBCPP_VISIBLE unique_lock
105{
106public:
107    typedef _Mutex mutex_type;
108
109private:
110    mutex_type* __m_;
111    bool __owns_;
112
113public:
114    _LIBCPP_INLINE_VISIBILITY
115    unique_lock() _NOEXCEPT : __m_(nullptr), __owns_(false) {}
116    _LIBCPP_INLINE_VISIBILITY
117    explicit unique_lock(mutex_type& __m)
118        : __m_(&__m), __owns_(true) {__m_->lock();}
119    _LIBCPP_INLINE_VISIBILITY
120    unique_lock(mutex_type& __m, defer_lock_t) _NOEXCEPT
121        : __m_(&__m), __owns_(false) {}
122    _LIBCPP_INLINE_VISIBILITY
123    unique_lock(mutex_type& __m, try_to_lock_t)
124        : __m_(&__m), __owns_(__m.try_lock()) {}
125    _LIBCPP_INLINE_VISIBILITY
126    unique_lock(mutex_type& __m, adopt_lock_t)
127        : __m_(&__m), __owns_(true) {}
128    template <class _Clock, class _Duration>
129    _LIBCPP_INLINE_VISIBILITY
130        unique_lock(mutex_type& __m, const chrono::time_point<_Clock, _Duration>& __t)
131            : __m_(&__m), __owns_(__m.try_lock_until(__t)) {}
132    template <class _Rep, class _Period>
133    _LIBCPP_INLINE_VISIBILITY
134        unique_lock(mutex_type& __m, const chrono::duration<_Rep, _Period>& __d)
135            : __m_(&__m), __owns_(__m.try_lock_for(__d)) {}
136    _LIBCPP_INLINE_VISIBILITY
137    ~unique_lock()
138    {
139        if (__owns_)
140            __m_->unlock();
141    }
142
143private:
144    unique_lock(unique_lock const&); // = delete;
145    unique_lock& operator=(unique_lock const&); // = delete;
146
147public:
148#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
149    _LIBCPP_INLINE_VISIBILITY
150    unique_lock(unique_lock&& __u) _NOEXCEPT
151        : __m_(__u.__m_), __owns_(__u.__owns_)
152        {__u.__m_ = nullptr; __u.__owns_ = false;}
153    _LIBCPP_INLINE_VISIBILITY
154    unique_lock& operator=(unique_lock&& __u) _NOEXCEPT
155        {
156            if (__owns_)
157                __m_->unlock();
158            __m_ = __u.__m_;
159            __owns_ = __u.__owns_;
160            __u.__m_ = nullptr;
161            __u.__owns_ = false;
162            return *this;
163        }
164
165#ifdef _LIBCPP_SHARED_LOCK
166
167    unique_lock(ting::shared_lock<mutex_type>&&, try_to_lock_t);
168    template <class _Clock, class _Duration>
169        unique_lock(ting::shared_lock<mutex_type>&&,
170                    const chrono::time_point<_Clock, _Duration>&);
171    template <class _Rep, class _Period>
172        unique_lock(ting::shared_lock<mutex_type>&&,
173                    const chrono::duration<_Rep, _Period>&);
174
175    explicit unique_lock(ting::upgrade_lock<mutex_type>&&);
176    unique_lock(ting::upgrade_lock<mutex_type>&&, try_to_lock_t);
177    template <class _Clock, class _Duration>
178        unique_lock(ting::upgrade_lock<mutex_type>&&,
179                    const chrono::time_point<_Clock, _Duration>&);
180    template <class _Rep, class _Period>
181        unique_lock(ting::upgrade_lock<mutex_type>&&,
182                    const chrono::duration<_Rep, _Period>&);
183
184#endif  // _LIBCPP_SHARED_LOCK
185
186#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
187
188    void lock();
189    bool try_lock();
190
191    template <class _Rep, class _Period>
192        bool try_lock_for(const chrono::duration<_Rep, _Period>& __d);
193    template <class _Clock, class _Duration>
194        bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
195
196    void unlock();
197
198    _LIBCPP_INLINE_VISIBILITY
199    void swap(unique_lock& __u) _NOEXCEPT
200    {
201        _VSTD::swap(__m_, __u.__m_);
202        _VSTD::swap(__owns_, __u.__owns_);
203    }
204    _LIBCPP_INLINE_VISIBILITY
205    mutex_type* release() _NOEXCEPT
206    {
207        mutex_type* __m = __m_;
208        __m_ = nullptr;
209        __owns_ = false;
210        return __m;
211    }
212
213    _LIBCPP_INLINE_VISIBILITY
214    bool owns_lock() const _NOEXCEPT {return __owns_;}
215    _LIBCPP_INLINE_VISIBILITY
216    _LIBCPP_EXPLICIT
217        operator bool () const _NOEXCEPT {return __owns_;}
218    _LIBCPP_INLINE_VISIBILITY
219    mutex_type* mutex() const _NOEXCEPT {return __m_;}
220};
221
222template <class _Mutex>
223void
224unique_lock<_Mutex>::lock()
225{
226    if (__m_ == nullptr)
227        __throw_system_error(EPERM, "unique_lock::lock: references null mutex");
228    if (__owns_)
229        __throw_system_error(EDEADLK, "unique_lock::lock: already locked");
230    __m_->lock();
231    __owns_ = true;
232}
233
234template <class _Mutex>
235bool
236unique_lock<_Mutex>::try_lock()
237{
238    if (__m_ == nullptr)
239        __throw_system_error(EPERM, "unique_lock::try_lock: references null mutex");
240    if (__owns_)
241        __throw_system_error(EDEADLK, "unique_lock::try_lock: already locked");
242    __owns_ = __m_->try_lock();
243    return __owns_;
244}
245
246template <class _Mutex>
247template <class _Rep, class _Period>
248bool
249unique_lock<_Mutex>::try_lock_for(const chrono::duration<_Rep, _Period>& __d)
250{
251    if (__m_ == nullptr)
252        __throw_system_error(EPERM, "unique_lock::try_lock_for: references null mutex");
253    if (__owns_)
254        __throw_system_error(EDEADLK, "unique_lock::try_lock_for: already locked");
255    __owns_ = __m_->try_lock_for(__d);
256    return __owns_;
257}
258
259template <class _Mutex>
260template <class _Clock, class _Duration>
261bool
262unique_lock<_Mutex>::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
263{
264    if (__m_ == nullptr)
265        __throw_system_error(EPERM, "unique_lock::try_lock_until: references null mutex");
266    if (__owns_)
267        __throw_system_error(EDEADLK, "unique_lock::try_lock_until: already locked");
268    __owns_ = __m_->try_lock_until(__t);
269    return __owns_;
270}
271
272template <class _Mutex>
273void
274unique_lock<_Mutex>::unlock()
275{
276    if (!__owns_)
277        __throw_system_error(EPERM, "unique_lock::unlock: not locked");
278    __m_->unlock();
279    __owns_ = false;
280}
281
282template <class _Mutex>
283inline _LIBCPP_INLINE_VISIBILITY
284void
285swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) _NOEXCEPT
286    {__x.swap(__y);}
287
288struct _LIBCPP_VISIBLE cv_status
289{
290    enum _ {
291        no_timeout,
292        timeout
293    };
294
295    _ __v_;
296
297    _LIBCPP_INLINE_VISIBILITY cv_status(_ __v) : __v_(__v) {}
298    _LIBCPP_INLINE_VISIBILITY operator int() const {return __v_;}
299
300};
301
302class _LIBCPP_VISIBLE condition_variable
303{
304    pthread_cond_t __cv_;
305public:
306    _LIBCPP_INLINE_VISIBILITY
307#ifndef _LIBCPP_HAS_NO_CONSTEXPR
308    constexpr condition_variable() : __cv_ PTHREAD_COND_INITIALIZER {}
309#else
310    condition_variable() {__cv_ = (pthread_cond_t)PTHREAD_COND_INITIALIZER;}
311#endif
312    ~condition_variable();
313
314private:
315    condition_variable(const condition_variable&); // = delete;
316    condition_variable& operator=(const condition_variable&); // = delete;
317
318public:
319    void notify_one() _NOEXCEPT;
320    void notify_all() _NOEXCEPT;
321
322    void wait(unique_lock<mutex>& __lk);
323    template <class _Predicate>
324        void wait(unique_lock<mutex>& __lk, _Predicate __pred);
325
326    template <class _Duration>
327        cv_status
328        wait_until(unique_lock<mutex>& __lk,
329                   const chrono::time_point<chrono::system_clock, _Duration>& __t);
330
331    template <class _Clock, class _Duration>
332        cv_status
333        wait_until(unique_lock<mutex>& __lk,
334                   const chrono::time_point<_Clock, _Duration>& __t);
335
336    template <class _Clock, class _Duration, class _Predicate>
337        bool
338        wait_until(unique_lock<mutex>& __lk,
339                   const chrono::time_point<_Clock, _Duration>& __t,
340                   _Predicate __pred);
341
342    template <class _Rep, class _Period>
343        cv_status
344        wait_for(unique_lock<mutex>& __lk,
345                 const chrono::duration<_Rep, _Period>& __d);
346
347    template <class _Rep, class _Period, class _Predicate>
348        bool
349        wait_for(unique_lock<mutex>& __lk,
350                 const chrono::duration<_Rep, _Period>& __d,
351                 _Predicate __pred);
352
353    typedef pthread_cond_t* native_handle_type;
354    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__cv_;}
355
356private:
357    void __do_timed_wait(unique_lock<mutex>& __lk,
358                 chrono::time_point<chrono::system_clock, chrono::nanoseconds>);
359};
360
361template <class _To, class _Rep, class _Period>
362inline _LIBCPP_INLINE_VISIBILITY
363typename enable_if
364<
365    chrono::__is_duration<_To>::value,
366    _To
367>::type
368__ceil(chrono::duration<_Rep, _Period> __d)
369{
370    using namespace chrono;
371    _To __r = duration_cast<_To>(__d);
372    if (__r < __d)
373        ++__r;
374    return __r;
375}
376
377template <class _Predicate>
378void
379condition_variable::wait(unique_lock<mutex>& __lk, _Predicate __pred)
380{
381    while (!__pred())
382        wait(__lk);
383}
384
385template <class _Duration>
386cv_status
387condition_variable::wait_until(unique_lock<mutex>& __lk,
388                 const chrono::time_point<chrono::system_clock, _Duration>& __t)
389{
390    using namespace chrono;
391    typedef time_point<system_clock, nanoseconds> __nano_sys_tmpt;
392    __do_timed_wait(__lk,
393                  __nano_sys_tmpt(__ceil<nanoseconds>(__t.time_since_epoch())));
394    return system_clock::now() < __t ? cv_status::no_timeout :
395                                       cv_status::timeout;
396}
397
398template <class _Clock, class _Duration>
399cv_status
400condition_variable::wait_until(unique_lock<mutex>& __lk,
401                               const chrono::time_point<_Clock, _Duration>& __t)
402{
403    using namespace chrono;
404    system_clock::time_point     __s_now = system_clock::now();
405    typename _Clock::time_point  __c_now = _Clock::now();
406    __do_timed_wait(__lk, __s_now + __ceil<nanoseconds>(__t - __c_now));
407    return _Clock::now() < __t ? cv_status::no_timeout : cv_status::timeout;
408}
409
410template <class _Clock, class _Duration, class _Predicate>
411bool
412condition_variable::wait_until(unique_lock<mutex>& __lk,
413                   const chrono::time_point<_Clock, _Duration>& __t,
414                   _Predicate __pred)
415{
416    while (!__pred())
417    {
418        if (wait_until(__lk, __t) == cv_status::timeout)
419            return __pred();
420    }
421    return true;
422}
423
424template <class _Rep, class _Period>
425cv_status
426condition_variable::wait_for(unique_lock<mutex>& __lk,
427                             const chrono::duration<_Rep, _Period>& __d)
428{
429    using namespace chrono;
430    system_clock::time_point __s_now = system_clock::now();
431    steady_clock::time_point __c_now = steady_clock::now();
432    __do_timed_wait(__lk, __s_now + __ceil<nanoseconds>(__d));
433    return steady_clock::now() - __c_now < __d ? cv_status::no_timeout :
434                                                 cv_status::timeout;
435}
436
437template <class _Rep, class _Period, class _Predicate>
438inline _LIBCPP_INLINE_VISIBILITY
439bool
440condition_variable::wait_for(unique_lock<mutex>& __lk,
441                             const chrono::duration<_Rep, _Period>& __d,
442                             _Predicate __pred)
443{
444    return wait_until(__lk, chrono::steady_clock::now() + __d,
445                      _VSTD::move(__pred));
446}
447
448_LIBCPP_END_NAMESPACE_STD
449
450#endif  // _LIBCPP___MUTEX_BASE
451