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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 
20 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
21 # include <sys/param.h>
22 # if defined(BSD)
23 #   include <sys/sysctl.h>
24 # endif // defined(BSD)
25 #endif // defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
26 
27 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__CloudABI__) || defined(__Fuchsia__)
28 # include <unistd.h>
29 #endif // defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__CloudABI__) || defined(__Fuchsia__)
30 
31 #if defined(__NetBSD__)
32 #pragma weak pthread_create // Do not create libpthread dependency
33 #endif
34 
35 #if defined(_LIBCPP_WIN32API)
36 #include <windows.h>
37 #endif // defined(_LIBCPP_WIN32API)
38 
39 _LIBCPP_BEGIN_NAMESPACE_STD
40 
~thread()41 thread::~thread()
42 {
43     if (!__libcpp_thread_isnull(&__t_))
44         terminate();
45 }
46 
47 void
join()48 thread::join()
49 {
50     int ec = EINVAL;
51     if (!__libcpp_thread_isnull(&__t_))
52     {
53         ec = __libcpp_thread_join(&__t_);
54         if (ec == 0)
55             __t_ = _LIBCPP_NULL_THREAD;
56     }
57 
58     if (ec)
59         __throw_system_error(ec, "thread::join failed");
60 }
61 
62 void
detach()63 thread::detach()
64 {
65     int ec = EINVAL;
66     if (!__libcpp_thread_isnull(&__t_))
67     {
68         ec = __libcpp_thread_detach(&__t_);
69         if (ec == 0)
70             __t_ = _LIBCPP_NULL_THREAD;
71     }
72 
73     if (ec)
74         __throw_system_error(ec, "thread::detach failed");
75 }
76 
77 unsigned
hardware_concurrency()78 thread::hardware_concurrency() _NOEXCEPT
79 {
80 #if defined(CTL_HW) && defined(HW_NCPU)
81     unsigned n;
82     int mib[2] = {CTL_HW, HW_NCPU};
83     std::size_t s = sizeof(n);
84     sysctl(mib, 2, &n, &s, 0, 0);
85     return n;
86 #elif defined(_SC_NPROCESSORS_ONLN)
87     long result = sysconf(_SC_NPROCESSORS_ONLN);
88     // sysconf returns -1 if the name is invalid, the option does not exist or
89     // does not have a definite limit.
90     // if sysconf returns some other negative number, we have no idea
91     // what is going on. Default to something safe.
92     if (result < 0)
93         return 0;
94     return static_cast<unsigned>(result);
95 #elif defined(_LIBCPP_WIN32API)
96     SYSTEM_INFO info;
97     GetSystemInfo(&info);
98     return info.dwNumberOfProcessors;
99 #else  // defined(CTL_HW) && defined(HW_NCPU)
100     // TODO: grovel through /proc or check cpuid on x86 and similar
101     // instructions on other architectures.
102 #   if defined(_LIBCPP_MSVC)
103         _LIBCPP_WARNING("hardware_concurrency not yet implemented")
104 #   else
105 #       warning hardware_concurrency not yet implemented
106 #   endif
107     return 0;  // Means not computable [thread.thread.static]
108 #endif  // defined(CTL_HW) && defined(HW_NCPU)
109 }
110 
111 namespace this_thread
112 {
113 
114 void
sleep_for(const chrono::nanoseconds & ns)115 sleep_for(const chrono::nanoseconds& ns)
116 {
117     if (ns > chrono::nanoseconds::zero())
118     {
119         __libcpp_thread_sleep_for(ns);
120     }
121 }
122 
123 }  // this_thread
124 
125 __thread_specific_ptr<__thread_struct>&
__thread_local_data()126 __thread_local_data()
127 {
128     static __thread_specific_ptr<__thread_struct> __p;
129     return __p;
130 }
131 
132 // __thread_struct_imp
133 
134 template <class T>
135 class _LIBCPP_HIDDEN __hidden_allocator
136 {
137 public:
138     typedef T  value_type;
139 
allocate(size_t __n)140     T* allocate(size_t __n)
141         {return static_cast<T*>(::operator new(__n * sizeof(T)));}
deallocate(T * __p,size_t)142     void deallocate(T* __p, size_t) {::operator delete(static_cast<void*>(__p));}
143 
max_size() const144     size_t max_size() const {return size_t(~0) / sizeof(T);}
145 };
146 
147 class _LIBCPP_HIDDEN __thread_struct_imp
148 {
149     typedef vector<__assoc_sub_state*,
150                           __hidden_allocator<__assoc_sub_state*> > _AsyncStates;
151     typedef vector<pair<condition_variable*, mutex*>,
152                __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify;
153 
154     _AsyncStates async_states_;
155     _Notify notify_;
156 
157     __thread_struct_imp(const __thread_struct_imp&);
158     __thread_struct_imp& operator=(const __thread_struct_imp&);
159 public:
__thread_struct_imp()160     __thread_struct_imp() {}
161     ~__thread_struct_imp();
162 
163     void notify_all_at_thread_exit(condition_variable* cv, mutex* m);
164     void __make_ready_at_thread_exit(__assoc_sub_state* __s);
165 };
166 
~__thread_struct_imp()167 __thread_struct_imp::~__thread_struct_imp()
168 {
169     for (_Notify::iterator i = notify_.begin(), e = notify_.end();
170             i != e; ++i)
171     {
172         i->second->unlock();
173         i->first->notify_all();
174     }
175     for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end();
176             i != e; ++i)
177     {
178         (*i)->__make_ready();
179         (*i)->__release_shared();
180     }
181 }
182 
183 void
notify_all_at_thread_exit(condition_variable * cv,mutex * m)184 __thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
185 {
186     notify_.push_back(pair<condition_variable*, mutex*>(cv, m));
187 }
188 
189 void
__make_ready_at_thread_exit(__assoc_sub_state * __s)190 __thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s)
191 {
192     async_states_.push_back(__s);
193     __s->__add_shared();
194 }
195 
196 // __thread_struct
197 
__thread_struct()198 __thread_struct::__thread_struct()
199     : __p_(new __thread_struct_imp)
200 {
201 }
202 
~__thread_struct()203 __thread_struct::~__thread_struct()
204 {
205     delete __p_;
206 }
207 
208 void
notify_all_at_thread_exit(condition_variable * cv,mutex * m)209 __thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
210 {
211     __p_->notify_all_at_thread_exit(cv, m);
212 }
213 
214 void
__make_ready_at_thread_exit(__assoc_sub_state * __s)215 __thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s)
216 {
217     __p_->__make_ready_at_thread_exit(__s);
218 }
219 
220 _LIBCPP_END_NAMESPACE_STD
221 
222 #endif // !_LIBCPP_HAS_NO_THREADS
223