1// -*- C++ -*-
2//===--------------------------- thread -----------------------------------===//
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_THREAD
12#define _LIBCPP_THREAD
13
14/*
15
16    thread synopsis
17
18#define __STDCPP_THREADS__ __cplusplus
19
20namespace std
21{
22
23class thread
24{
25public:
26    class id;
27    typedef pthread_t native_handle_type;
28
29    thread() noexcept;
30    template <class F, class ...Args> explicit thread(F&& f, Args&&... args);
31    ~thread();
32
33    thread(const thread&) = delete;
34    thread(thread&& t) noexcept;
35
36    thread& operator=(const thread&) = delete;
37    thread& operator=(thread&& t) noexcept;
38
39    void swap(thread& t) noexcept;
40
41    bool joinable() const noexcept;
42    void join();
43    void detach();
44    id get_id() const noexcept;
45    native_handle_type native_handle();
46
47    static unsigned hardware_concurrency() noexcept;
48};
49
50void swap(thread& x, thread& y) noexcept;
51
52class thread::id
53{
54public:
55    id() noexcept;
56};
57
58bool operator==(thread::id x, thread::id y) noexcept;
59bool operator!=(thread::id x, thread::id y) noexcept;
60bool operator< (thread::id x, thread::id y) noexcept;
61bool operator<=(thread::id x, thread::id y) noexcept;
62bool operator> (thread::id x, thread::id y) noexcept;
63bool operator>=(thread::id x, thread::id y) noexcept;
64
65template<class charT, class traits>
66basic_ostream<charT, traits>&
67operator<<(basic_ostream<charT, traits>& out, thread::id id);
68
69namespace this_thread
70{
71
72thread::id get_id() noexcept;
73
74void yield() noexcept;
75
76template <class Clock, class Duration>
77void sleep_until(const chrono::time_point<Clock, Duration>& abs_time);
78
79template <class Rep, class Period>
80void sleep_for(const chrono::duration<Rep, Period>& rel_time);
81
82}  // this_thread
83
84}  // std
85
86*/
87
88#include <__config>
89#include <iosfwd>
90#include <__functional_base>
91#include <type_traits>
92#include <cstddef>
93#include <functional>
94#include <memory>
95#include <system_error>
96#include <chrono>
97#include <__mutex_base>
98#ifndef _LIBCPP_HAS_NO_VARIADICS
99#include <tuple>
100#endif
101#include <pthread.h>
102
103#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
104#pragma GCC system_header
105#endif
106
107#define __STDCPP_THREADS__ __cplusplus
108
109#if !_LIBCPP_SINGLE_THREADED
110
111_LIBCPP_BEGIN_NAMESPACE_STD
112
113template <class _Tp>
114class __thread_specific_ptr
115{
116    pthread_key_t __key_;
117
118    __thread_specific_ptr(const __thread_specific_ptr&);
119    __thread_specific_ptr& operator=(const __thread_specific_ptr&);
120
121    static void __at_thread_exit(void*);
122public:
123    typedef _Tp* pointer;
124
125    __thread_specific_ptr();
126    ~__thread_specific_ptr();
127
128    _LIBCPP_INLINE_VISIBILITY
129    pointer get() const {return static_cast<_Tp*>(pthread_getspecific(__key_));}
130    _LIBCPP_INLINE_VISIBILITY
131    pointer operator*() const {return *get();}
132    _LIBCPP_INLINE_VISIBILITY
133    pointer operator->() const {return get();}
134    pointer release();
135    void reset(pointer __p = nullptr);
136};
137
138template <class _Tp>
139void
140__thread_specific_ptr<_Tp>::__at_thread_exit(void* __p)
141{
142    delete static_cast<pointer>(__p);
143}
144
145template <class _Tp>
146__thread_specific_ptr<_Tp>::__thread_specific_ptr()
147{
148    int __ec = pthread_key_create(&__key_, &__thread_specific_ptr::__at_thread_exit);
149#ifndef _LIBCPP_NO_EXCEPTIONS
150    if (__ec)
151        throw system_error(error_code(__ec, system_category()),
152                           "__thread_specific_ptr construction failed");
153#endif
154}
155
156template <class _Tp>
157__thread_specific_ptr<_Tp>::~__thread_specific_ptr()
158{
159    pthread_key_delete(__key_);
160}
161
162template <class _Tp>
163typename __thread_specific_ptr<_Tp>::pointer
164__thread_specific_ptr<_Tp>::release()
165{
166    pointer __p = get();
167    pthread_setspecific(__key_, 0);
168    return __p;
169}
170
171template <class _Tp>
172void
173__thread_specific_ptr<_Tp>::reset(pointer __p)
174{
175    pointer __p_old = get();
176    pthread_setspecific(__key_, __p);
177    delete __p_old;
178}
179
180class _LIBCPP_TYPE_VIS thread;
181class _LIBCPP_TYPE_VIS __thread_id;
182
183namespace this_thread
184{
185
186_LIBCPP_INLINE_VISIBILITY __thread_id get_id() _NOEXCEPT;
187
188}  // this_thread
189
190template<> struct _LIBCPP_TYPE_VIS_ONLY hash<__thread_id>;
191
192class _LIBCPP_TYPE_VIS_ONLY __thread_id
193{
194    // FIXME: pthread_t is a pointer on Darwin but a long on Linux.
195    // NULL is the no-thread value on Darwin.  Someone needs to check
196    // on other platforms.  We assume 0 works everywhere for now.
197    pthread_t __id_;
198
199public:
200    _LIBCPP_INLINE_VISIBILITY
201    __thread_id() _NOEXCEPT : __id_(0) {}
202
203    friend _LIBCPP_INLINE_VISIBILITY
204        bool operator==(__thread_id __x, __thread_id __y) _NOEXCEPT
205        {return __x.__id_ == __y.__id_;}
206    friend _LIBCPP_INLINE_VISIBILITY
207        bool operator!=(__thread_id __x, __thread_id __y) _NOEXCEPT
208        {return !(__x == __y);}
209    friend _LIBCPP_INLINE_VISIBILITY
210        bool operator< (__thread_id __x, __thread_id __y) _NOEXCEPT
211        {return __x.__id_ < __y.__id_;}
212    friend _LIBCPP_INLINE_VISIBILITY
213        bool operator<=(__thread_id __x, __thread_id __y) _NOEXCEPT
214        {return !(__y < __x);}
215    friend _LIBCPP_INLINE_VISIBILITY
216        bool operator> (__thread_id __x, __thread_id __y) _NOEXCEPT
217        {return   __y < __x ;}
218    friend _LIBCPP_INLINE_VISIBILITY
219        bool operator>=(__thread_id __x, __thread_id __y) _NOEXCEPT
220        {return !(__x < __y);}
221
222    template<class _CharT, class _Traits>
223    friend
224    _LIBCPP_INLINE_VISIBILITY
225    basic_ostream<_CharT, _Traits>&
226    operator<<(basic_ostream<_CharT, _Traits>& __os, __thread_id __id)
227        {return __os << __id.__id_;}
228
229private:
230    _LIBCPP_INLINE_VISIBILITY
231    __thread_id(pthread_t __id) : __id_(__id) {}
232
233    friend __thread_id this_thread::get_id() _NOEXCEPT;
234    friend class _LIBCPP_TYPE_VIS thread;
235    friend struct _LIBCPP_TYPE_VIS_ONLY hash<__thread_id>;
236};
237
238template<>
239struct _LIBCPP_TYPE_VIS_ONLY hash<__thread_id>
240    : public unary_function<__thread_id, size_t>
241{
242    _LIBCPP_INLINE_VISIBILITY
243    size_t operator()(__thread_id __v) const
244    {
245        return hash<pthread_t>()(__v.__id_);
246    }
247};
248
249namespace this_thread
250{
251
252inline _LIBCPP_INLINE_VISIBILITY
253__thread_id
254get_id() _NOEXCEPT
255{
256    return pthread_self();
257}
258
259}  // this_thread
260
261class _LIBCPP_TYPE_VIS thread
262{
263    pthread_t __t_;
264
265    thread(const thread&);
266    thread& operator=(const thread&);
267public:
268    typedef __thread_id id;
269    typedef pthread_t native_handle_type;
270
271    _LIBCPP_INLINE_VISIBILITY
272    thread() _NOEXCEPT : __t_(0) {}
273#ifndef _LIBCPP_HAS_NO_VARIADICS
274    template <class _Fp, class ..._Args,
275              class = typename enable_if
276              <
277                   !is_same<typename decay<_Fp>::type, thread>::value
278              >::type
279             >
280        explicit thread(_Fp&& __f, _Args&&... __args);
281#else  // _LIBCPP_HAS_NO_VARIADICS
282    template <class _Fp> explicit thread(_Fp __f);
283#endif
284    ~thread();
285
286#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
287    _LIBCPP_INLINE_VISIBILITY
288    thread(thread&& __t) _NOEXCEPT : __t_(__t.__t_) {__t.__t_ = 0;}
289    thread& operator=(thread&& __t) _NOEXCEPT;
290#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
291
292    _LIBCPP_INLINE_VISIBILITY
293    void swap(thread& __t) _NOEXCEPT {_VSTD::swap(__t_, __t.__t_);}
294
295    _LIBCPP_INLINE_VISIBILITY
296    bool joinable() const _NOEXCEPT {return __t_ != 0;}
297    void join();
298    void detach();
299    _LIBCPP_INLINE_VISIBILITY
300    id get_id() const _NOEXCEPT {return __t_;}
301    _LIBCPP_INLINE_VISIBILITY
302    native_handle_type native_handle() _NOEXCEPT {return __t_;}
303
304    static unsigned hardware_concurrency() _NOEXCEPT;
305};
306
307class __assoc_sub_state;
308
309class _LIBCPP_HIDDEN __thread_struct_imp;
310
311class _LIBCPP_TYPE_VIS __thread_struct
312{
313    __thread_struct_imp* __p_;
314
315    __thread_struct(const __thread_struct&);
316    __thread_struct& operator=(const __thread_struct&);
317public:
318    __thread_struct();
319    ~__thread_struct();
320
321    void notify_all_at_thread_exit(condition_variable*, mutex*);
322    void __make_ready_at_thread_exit(__assoc_sub_state*);
323};
324
325_LIBCPP_FUNC_VIS __thread_specific_ptr<__thread_struct>& __thread_local_data();
326
327#ifndef _LIBCPP_HAS_NO_VARIADICS
328
329template <class _Fp, class ..._Args, size_t ..._Indices>
330inline _LIBCPP_INLINE_VISIBILITY
331void
332__thread_execute(tuple<_Fp, _Args...>& __t, __tuple_indices<_Indices...>)
333{
334    __invoke(_VSTD::move(_VSTD::get<0>(__t)), _VSTD::move(_VSTD::get<_Indices>(__t))...);
335}
336
337template <class _Fp>
338void*
339__thread_proxy(void* __vp)
340{
341    __thread_local_data().reset(new __thread_struct);
342    std::unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp));
343    typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 1>::type _Index;
344    __thread_execute(*__p, _Index());
345    return nullptr;
346}
347
348template <class _Fp, class ..._Args,
349          class
350         >
351thread::thread(_Fp&& __f, _Args&&... __args)
352{
353    typedef tuple<typename decay<_Fp>::type, typename decay<_Args>::type...> _Gp;
354    _VSTD::unique_ptr<_Gp> __p(new _Gp(__decay_copy(_VSTD::forward<_Fp>(__f)),
355                                __decay_copy(_VSTD::forward<_Args>(__args))...));
356    int __ec = pthread_create(&__t_, 0, &__thread_proxy<_Gp>, __p.get());
357    if (__ec == 0)
358        __p.release();
359    else
360        __throw_system_error(__ec, "thread constructor failed");
361}
362
363#else  // _LIBCPP_HAS_NO_VARIADICS
364
365template <class _Fp>
366void*
367__thread_proxy(void* __vp)
368{
369    __thread_local_data().reset(new __thread_struct);
370    std::unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp));
371    (*__p)();
372    return nullptr;
373}
374
375template <class _Fp>
376thread::thread(_Fp __f)
377{
378    std::unique_ptr<_Fp> __p(new _Fp(__f));
379    int __ec = pthread_create(&__t_, 0, &__thread_proxy<_Fp>, __p.get());
380    if (__ec == 0)
381        __p.release();
382    else
383        __throw_system_error(__ec, "thread constructor failed");
384}
385
386#endif  // _LIBCPP_HAS_NO_VARIADICS
387
388#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
389
390inline _LIBCPP_INLINE_VISIBILITY
391thread&
392thread::operator=(thread&& __t) _NOEXCEPT
393{
394    if (__t_ != 0)
395        terminate();
396    __t_ = __t.__t_;
397    __t.__t_ = 0;
398    return *this;
399}
400
401#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
402
403inline _LIBCPP_INLINE_VISIBILITY
404void swap(thread& __x, thread& __y) _NOEXCEPT {__x.swap(__y);}
405
406namespace this_thread
407{
408
409_LIBCPP_FUNC_VIS void sleep_for(const chrono::nanoseconds& ns);
410
411template <class _Rep, class _Period>
412void
413sleep_for(const chrono::duration<_Rep, _Period>& __d)
414{
415    using namespace chrono;
416    if (__d > duration<_Rep, _Period>::zero())
417    {
418        _LIBCPP_CONSTEXPR duration<long double> _Max = nanoseconds::max();
419        nanoseconds __ns;
420        if (__d < _Max)
421        {
422            __ns = duration_cast<nanoseconds>(__d);
423            if (__ns < __d)
424                ++__ns;
425        }
426        else
427            __ns = nanoseconds::max();
428        sleep_for(__ns);
429    }
430}
431
432template <class _Clock, class _Duration>
433void
434sleep_until(const chrono::time_point<_Clock, _Duration>& __t)
435{
436    using namespace chrono;
437    mutex __mut;
438    condition_variable __cv;
439    unique_lock<mutex> __lk(__mut);
440    while (_Clock::now() < __t)
441        __cv.wait_until(__lk, __t);
442}
443
444template <class _Duration>
445inline _LIBCPP_INLINE_VISIBILITY
446void
447sleep_until(const chrono::time_point<chrono::steady_clock, _Duration>& __t)
448{
449    using namespace chrono;
450    sleep_for(__t - steady_clock::now());
451}
452
453inline _LIBCPP_INLINE_VISIBILITY
454void yield() _NOEXCEPT {sched_yield();}
455
456}  // this_thread
457
458_LIBCPP_END_NAMESPACE_STD
459
460#endif // !_LIBCPP_SINGLE_THREADED
461
462#endif  // _LIBCPP_THREAD
463