1//===------------------------- thread.cpp----------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "__config"
11#ifndef _LIBCPP_HAS_NO_THREADS
12
13#include "thread"
14#include "exception"
15#include "vector"
16#include "future"
17#include "limits"
18#include <sys/types.h>
19#if !defined(_WIN32)
20# if !defined(__sun__) && !defined(__linux__) && !defined(_AIX) && !defined(__native_client__) && !defined(__CloudABI__)
21#   include <sys/sysctl.h>
22# endif // !defined(__sun__) && !defined(__linux__) && !defined(_AIX) && !defined(__native_client__) && !defined(__CloudABI__)
23# include <unistd.h>
24#endif // !_WIN32
25
26#if defined(__NetBSD__)
27#pragma weak pthread_create // Do not create libpthread dependency
28#endif
29#if defined(_WIN32)
30#include <windows.h>
31#endif
32
33_LIBCPP_BEGIN_NAMESPACE_STD
34
35thread::~thread()
36{
37    if (__t_ != 0)
38        terminate();
39}
40
41void
42thread::join()
43{
44    int ec = pthread_join(__t_, 0);
45#ifndef _LIBCPP_NO_EXCEPTIONS
46    if (ec)
47        throw system_error(error_code(ec, system_category()), "thread::join failed");
48#else
49    (void)ec;
50#endif  // _LIBCPP_NO_EXCEPTIONS
51    __t_ = 0;
52}
53
54void
55thread::detach()
56{
57    int ec = EINVAL;
58    if (__t_ != 0)
59    {
60        ec = pthread_detach(__t_);
61        if (ec == 0)
62            __t_ = 0;
63    }
64#ifndef _LIBCPP_NO_EXCEPTIONS
65    if (ec)
66        throw system_error(error_code(ec, system_category()), "thread::detach failed");
67#endif  // _LIBCPP_NO_EXCEPTIONS
68}
69
70unsigned
71thread::hardware_concurrency() _NOEXCEPT
72{
73#if defined(CTL_HW) && defined(HW_NCPU)
74    unsigned n;
75    int mib[2] = {CTL_HW, HW_NCPU};
76    std::size_t s = sizeof(n);
77    sysctl(mib, 2, &n, &s, 0, 0);
78    return n;
79#elif defined(_SC_NPROCESSORS_ONLN)
80    long result = sysconf(_SC_NPROCESSORS_ONLN);
81    // sysconf returns -1 if the name is invalid, the option does not exist or
82    // does not have a definite limit.
83    // if sysconf returns some other negative number, we have no idea
84    // what is going on. Default to something safe.
85    if (result < 0)
86        return 0;
87    return static_cast<unsigned>(result);
88#elif defined(_WIN32)
89    SYSTEM_INFO info;
90    GetSystemInfo(&info);
91    return info.dwNumberOfProcessors;
92#else  // defined(CTL_HW) && defined(HW_NCPU)
93    // TODO: grovel through /proc or check cpuid on x86 and similar
94    // instructions on other architectures.
95#   if defined(_MSC_VER) && ! defined(__clang__)
96        _LIBCPP_WARNING("hardware_concurrency not yet implemented")
97#   else
98#       warning hardware_concurrency not yet implemented
99#   endif
100    return 0;  // Means not computable [thread.thread.static]
101#endif  // defined(CTL_HW) && defined(HW_NCPU)
102}
103
104namespace this_thread
105{
106
107void
108sleep_for(const chrono::nanoseconds& ns)
109{
110    using namespace chrono;
111    if (ns > nanoseconds::zero())
112    {
113        seconds s = duration_cast<seconds>(ns);
114        timespec ts;
115        typedef decltype(ts.tv_sec) ts_sec;
116        _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max();
117        if (s.count() < ts_sec_max)
118        {
119            ts.tv_sec = static_cast<ts_sec>(s.count());
120            ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((ns-s).count());
121        }
122        else
123        {
124            ts.tv_sec = ts_sec_max;
125            ts.tv_nsec = giga::num - 1;
126        }
127
128        while (nanosleep(&ts, &ts) == -1 && errno == EINTR)
129            ;
130    }
131}
132
133}  // this_thread
134
135__thread_specific_ptr<__thread_struct>&
136__thread_local_data()
137{
138    static __thread_specific_ptr<__thread_struct> __p;
139    return __p;
140}
141
142// __thread_struct_imp
143
144template <class T>
145class _LIBCPP_HIDDEN __hidden_allocator
146{
147public:
148    typedef T  value_type;
149
150    T* allocate(size_t __n)
151        {return static_cast<T*>(::operator new(__n * sizeof(T)));}
152    void deallocate(T* __p, size_t) {::operator delete(static_cast<void*>(__p));}
153
154    size_t max_size() const {return size_t(~0) / sizeof(T);}
155};
156
157class _LIBCPP_HIDDEN __thread_struct_imp
158{
159    typedef vector<__assoc_sub_state*,
160                          __hidden_allocator<__assoc_sub_state*> > _AsyncStates;
161    typedef vector<pair<condition_variable*, mutex*>,
162               __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify;
163
164    _AsyncStates async_states_;
165    _Notify notify_;
166
167    __thread_struct_imp(const __thread_struct_imp&);
168    __thread_struct_imp& operator=(const __thread_struct_imp&);
169public:
170    __thread_struct_imp() {}
171    ~__thread_struct_imp();
172
173    void notify_all_at_thread_exit(condition_variable* cv, mutex* m);
174    void __make_ready_at_thread_exit(__assoc_sub_state* __s);
175};
176
177__thread_struct_imp::~__thread_struct_imp()
178{
179    for (_Notify::iterator i = notify_.begin(), e = notify_.end();
180            i != e; ++i)
181    {
182        i->second->unlock();
183        i->first->notify_all();
184    }
185    for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end();
186            i != e; ++i)
187    {
188        (*i)->__make_ready();
189        (*i)->__release_shared();
190    }
191}
192
193void
194__thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
195{
196    notify_.push_back(pair<condition_variable*, mutex*>(cv, m));
197}
198
199void
200__thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s)
201{
202    async_states_.push_back(__s);
203    __s->__add_shared();
204}
205
206// __thread_struct
207
208__thread_struct::__thread_struct()
209    : __p_(new __thread_struct_imp)
210{
211}
212
213__thread_struct::~__thread_struct()
214{
215    delete __p_;
216}
217
218void
219__thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
220{
221    __p_->notify_all_at_thread_exit(cv, m);
222}
223
224void
225__thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s)
226{
227    __p_->__make_ready_at_thread_exit(__s);
228}
229
230_LIBCPP_END_NAMESPACE_STD
231
232#endif // !_LIBCPP_HAS_NO_THREADS
233