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
~thread()35 thread::~thread()
36 {
37 if (__t_ != 0)
38 terminate();
39 }
40
41 void
join()42 thread::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
54 void
detach()55 thread::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
70 unsigned
hardware_concurrency()71 thread::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
104 namespace this_thread
105 {
106
107 void
sleep_for(const chrono::nanoseconds & ns)108 sleep_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>&
__thread_local_data()136 __thread_local_data()
137 {
138 static __thread_specific_ptr<__thread_struct> __p;
139 return __p;
140 }
141
142 // __thread_struct_imp
143
144 template <class T>
145 class _LIBCPP_HIDDEN __hidden_allocator
146 {
147 public:
148 typedef T value_type;
149
allocate(size_t __n)150 T* allocate(size_t __n)
151 {return static_cast<T*>(::operator new(__n * sizeof(T)));}
deallocate(T * __p,size_t)152 void deallocate(T* __p, size_t) {::operator delete(static_cast<void*>(__p));}
153
max_size() const154 size_t max_size() const {return size_t(~0) / sizeof(T);}
155 };
156
157 class _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&);
169 public:
__thread_struct_imp()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
~__thread_struct_imp()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
193 void
notify_all_at_thread_exit(condition_variable * cv,mutex * m)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
199 void
__make_ready_at_thread_exit(__assoc_sub_state * __s)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
__thread_struct()208 __thread_struct::__thread_struct()
209 : __p_(new __thread_struct_imp)
210 {
211 }
212
~__thread_struct()213 __thread_struct::~__thread_struct()
214 {
215 delete __p_;
216 }
217
218 void
notify_all_at_thread_exit(condition_variable * cv,mutex * m)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
224 void
__make_ready_at_thread_exit(__assoc_sub_state * __s)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