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 "thread"
11 #include "exception"
12 #include "vector"
13 #include "future"
14 #include "limits"
15 #include <sys/types.h>
16 #if !defined(_WIN32)
17 #if !defined(__sun__) && !defined(__linux__) && !defined(_AIX)
18 #include <sys/sysctl.h>
19 #endif // !__sun__ && !__linux__ && !_AIX
20 #include <unistd.h>
21 #endif // !_WIN32
22
23 #if defined(__NetBSD__)
24 #pragma weak pthread_create // Do not create libpthread dependency
25 #endif
26 #if defined(_WIN32)
27 #include <windows.h>
28 #endif
29
30 #if !_LIBCPP_SINGLE_THREADED
31
32 _LIBCPP_BEGIN_NAMESPACE_STD
33
~thread()34 thread::~thread()
35 {
36 if (__t_ != 0)
37 terminate();
38 }
39
40 void
join()41 thread::join()
42 {
43 int ec = pthread_join(__t_, 0);
44 #ifndef _LIBCPP_NO_EXCEPTIONS
45 if (ec)
46 throw system_error(error_code(ec, system_category()), "thread::join failed");
47 #else
48 (void)ec;
49 #endif // _LIBCPP_NO_EXCEPTIONS
50 __t_ = 0;
51 }
52
53 void
detach()54 thread::detach()
55 {
56 int ec = EINVAL;
57 if (__t_ != 0)
58 {
59 ec = pthread_detach(__t_);
60 if (ec == 0)
61 __t_ = 0;
62 }
63 #ifndef _LIBCPP_NO_EXCEPTIONS
64 if (ec)
65 throw system_error(error_code(ec, system_category()), "thread::detach failed");
66 #endif // _LIBCPP_NO_EXCEPTIONS
67 }
68
69 unsigned
hardware_concurrency()70 thread::hardware_concurrency() _NOEXCEPT
71 {
72 #if defined(CTL_HW) && defined(HW_NCPU)
73 unsigned n;
74 int mib[2] = {CTL_HW, HW_NCPU};
75 std::size_t s = sizeof(n);
76 sysctl(mib, 2, &n, &s, 0, 0);
77 return n;
78 #elif defined(_SC_NPROCESSORS_ONLN)
79 long result = sysconf(_SC_NPROCESSORS_ONLN);
80 // sysconf returns -1 if the name is invalid, the option does not exist or
81 // does not have a definite limit.
82 // if sysconf returns some other negative number, we have no idea
83 // what is going on. Default to something safe.
84 if (result < 0)
85 return 0;
86 return static_cast<unsigned>(result);
87 #elif defined(_WIN32)
88 SYSTEM_INFO info;
89 GetSystemInfo(&info);
90 return info.dwNumberOfProcessors;
91 #else // defined(CTL_HW) && defined(HW_NCPU)
92 // TODO: grovel through /proc or check cpuid on x86 and similar
93 // instructions on other architectures.
94 # if defined(_MSC_VER) && ! defined(__clang__)
95 _LIBCPP_WARNING("hardware_concurrency not yet implemented")
96 # else
97 # warning hardware_concurrency not yet implemented
98 # endif
99 return 0; // Means not computable [thread.thread.static]
100 #endif // defined(CTL_HW) && defined(HW_NCPU)
101 }
102
103 namespace this_thread
104 {
105
106 void
sleep_for(const chrono::nanoseconds & ns)107 sleep_for(const chrono::nanoseconds& ns)
108 {
109 using namespace chrono;
110 if (ns > nanoseconds::zero())
111 {
112 seconds s = duration_cast<seconds>(ns);
113 timespec ts;
114 typedef decltype(ts.tv_sec) ts_sec;
115 _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max();
116 if (s.count() < ts_sec_max)
117 {
118 ts.tv_sec = static_cast<ts_sec>(s.count());
119 ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((ns-s).count());
120 }
121 else
122 {
123 ts.tv_sec = ts_sec_max;
124 ts.tv_nsec = giga::num - 1;
125 }
126 #if (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 199309L) || defined(__ANDROID__)
127 while (nanosleep(&ts, &ts) == -1 && errno == EINTR)
128 ;
129 #else
130 #warning sleep_for not yet implemented
131 #endif
132 }
133 }
134
135 } // this_thread
136
137 __thread_specific_ptr<__thread_struct>&
__thread_local_data()138 __thread_local_data()
139 {
140 static __thread_specific_ptr<__thread_struct> __p;
141 return __p;
142 }
143
144 // __thread_struct_imp
145
146 template <class T>
147 class _LIBCPP_HIDDEN __hidden_allocator
148 {
149 public:
150 typedef T value_type;
151
allocate(size_t __n)152 T* allocate(size_t __n)
153 {return static_cast<T*>(::operator new(__n * sizeof(T)));}
deallocate(T * __p,size_t)154 void deallocate(T* __p, size_t) {::operator delete(static_cast<void*>(__p));}
155
max_size() const156 size_t max_size() const {return size_t(~0) / sizeof(T);}
157 };
158
159 class _LIBCPP_HIDDEN __thread_struct_imp
160 {
161 typedef vector<__assoc_sub_state*,
162 __hidden_allocator<__assoc_sub_state*> > _AsyncStates;
163 typedef vector<pair<condition_variable*, mutex*>,
164 __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify;
165
166 _AsyncStates async_states_;
167 _Notify notify_;
168
169 __thread_struct_imp(const __thread_struct_imp&);
170 __thread_struct_imp& operator=(const __thread_struct_imp&);
171 public:
__thread_struct_imp()172 __thread_struct_imp() {}
173 ~__thread_struct_imp();
174
175 void notify_all_at_thread_exit(condition_variable* cv, mutex* m);
176 void __make_ready_at_thread_exit(__assoc_sub_state* __s);
177 };
178
~__thread_struct_imp()179 __thread_struct_imp::~__thread_struct_imp()
180 {
181 for (_Notify::iterator i = notify_.begin(), e = notify_.end();
182 i != e; ++i)
183 {
184 i->second->unlock();
185 i->first->notify_all();
186 }
187 for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end();
188 i != e; ++i)
189 {
190 (*i)->__make_ready();
191 (*i)->__release_shared();
192 }
193 }
194
195 void
notify_all_at_thread_exit(condition_variable * cv,mutex * m)196 __thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
197 {
198 notify_.push_back(pair<condition_variable*, mutex*>(cv, m));
199 }
200
201 void
__make_ready_at_thread_exit(__assoc_sub_state * __s)202 __thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s)
203 {
204 async_states_.push_back(__s);
205 __s->__add_shared();
206 }
207
208 // __thread_struct
209
__thread_struct()210 __thread_struct::__thread_struct()
211 : __p_(new __thread_struct_imp)
212 {
213 }
214
~__thread_struct()215 __thread_struct::~__thread_struct()
216 {
217 delete __p_;
218 }
219
220 void
notify_all_at_thread_exit(condition_variable * cv,mutex * m)221 __thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
222 {
223 __p_->notify_all_at_thread_exit(cv, m);
224 }
225
226 void
__make_ready_at_thread_exit(__assoc_sub_state * __s)227 __thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s)
228 {
229 __p_->__make_ready_at_thread_exit(__s);
230 }
231
232 _LIBCPP_END_NAMESPACE_STD
233
234 #endif // !_LIBCPP_SINGLE_THREADED
235
236