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(_WIN32) 28 # include <unistd.h> 29 #endif // !_WIN32 30 31 #if defined(__NetBSD__) 32 #pragma weak pthread_create // Do not create libpthread dependency 33 #endif 34 #if defined(_WIN32) 35 #include <windows.h> 36 #endif 37 38 _LIBCPP_BEGIN_NAMESPACE_STD 39 40 thread::~thread() 41 { 42 if (__t_ != 0) 43 terminate(); 44 } 45 46 void 47 thread::join() 48 { 49 int ec = pthread_join(__t_, 0); 50 #ifndef _LIBCPP_NO_EXCEPTIONS 51 if (ec) 52 throw system_error(error_code(ec, system_category()), "thread::join failed"); 53 #else 54 (void)ec; 55 #endif // _LIBCPP_NO_EXCEPTIONS 56 __t_ = 0; 57 } 58 59 void 60 thread::detach() 61 { 62 int ec = EINVAL; 63 if (__t_ != 0) 64 { 65 ec = pthread_detach(__t_); 66 if (ec == 0) 67 __t_ = 0; 68 } 69 #ifndef _LIBCPP_NO_EXCEPTIONS 70 if (ec) 71 throw system_error(error_code(ec, system_category()), "thread::detach failed"); 72 #endif // _LIBCPP_NO_EXCEPTIONS 73 } 74 75 unsigned 76 thread::hardware_concurrency() _NOEXCEPT 77 { 78 #if defined(CTL_HW) && defined(HW_NCPU) 79 unsigned n; 80 int mib[2] = {CTL_HW, HW_NCPU}; 81 std::size_t s = sizeof(n); 82 sysctl(mib, 2, &n, &s, 0, 0); 83 return n; 84 #elif defined(_SC_NPROCESSORS_ONLN) 85 long result = sysconf(_SC_NPROCESSORS_ONLN); 86 // sysconf returns -1 if the name is invalid, the option does not exist or 87 // does not have a definite limit. 88 // if sysconf returns some other negative number, we have no idea 89 // what is going on. Default to something safe. 90 if (result < 0) 91 return 0; 92 return static_cast<unsigned>(result); 93 #elif defined(_WIN32) 94 SYSTEM_INFO info; 95 GetSystemInfo(&info); 96 return info.dwNumberOfProcessors; 97 #else // defined(CTL_HW) && defined(HW_NCPU) 98 // TODO: grovel through /proc or check cpuid on x86 and similar 99 // instructions on other architectures. 100 # if defined(_MSC_VER) && ! defined(__clang__) 101 _LIBCPP_WARNING("hardware_concurrency not yet implemented") 102 # else 103 # warning hardware_concurrency not yet implemented 104 # endif 105 return 0; // Means not computable [thread.thread.static] 106 #endif // defined(CTL_HW) && defined(HW_NCPU) 107 } 108 109 namespace this_thread 110 { 111 112 void 113 sleep_for(const chrono::nanoseconds& ns) 114 { 115 using namespace chrono; 116 if (ns > nanoseconds::zero()) 117 { 118 seconds s = duration_cast<seconds>(ns); 119 timespec ts; 120 typedef decltype(ts.tv_sec) ts_sec; 121 _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max(); 122 if (s.count() < ts_sec_max) 123 { 124 ts.tv_sec = static_cast<ts_sec>(s.count()); 125 ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((ns-s).count()); 126 } 127 else 128 { 129 ts.tv_sec = ts_sec_max; 130 ts.tv_nsec = giga::num - 1; 131 } 132 133 while (nanosleep(&ts, &ts) == -1 && errno == EINTR) 134 ; 135 } 136 } 137 138 } // this_thread 139 140 __thread_specific_ptr<__thread_struct>& 141 __thread_local_data() 142 { 143 static __thread_specific_ptr<__thread_struct> __p; 144 return __p; 145 } 146 147 // __thread_struct_imp 148 149 template <class T> 150 class _LIBCPP_HIDDEN __hidden_allocator 151 { 152 public: 153 typedef T value_type; 154 155 T* allocate(size_t __n) 156 {return static_cast<T*>(::operator new(__n * sizeof(T)));} 157 void deallocate(T* __p, size_t) {::operator delete(static_cast<void*>(__p));} 158 159 size_t max_size() const {return size_t(~0) / sizeof(T);} 160 }; 161 162 class _LIBCPP_HIDDEN __thread_struct_imp 163 { 164 typedef vector<__assoc_sub_state*, 165 __hidden_allocator<__assoc_sub_state*> > _AsyncStates; 166 typedef vector<pair<condition_variable*, mutex*>, 167 __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify; 168 169 _AsyncStates async_states_; 170 _Notify notify_; 171 172 __thread_struct_imp(const __thread_struct_imp&); 173 __thread_struct_imp& operator=(const __thread_struct_imp&); 174 public: 175 __thread_struct_imp() {} 176 ~__thread_struct_imp(); 177 178 void notify_all_at_thread_exit(condition_variable* cv, mutex* m); 179 void __make_ready_at_thread_exit(__assoc_sub_state* __s); 180 }; 181 182 __thread_struct_imp::~__thread_struct_imp() 183 { 184 for (_Notify::iterator i = notify_.begin(), e = notify_.end(); 185 i != e; ++i) 186 { 187 i->second->unlock(); 188 i->first->notify_all(); 189 } 190 for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end(); 191 i != e; ++i) 192 { 193 (*i)->__make_ready(); 194 (*i)->__release_shared(); 195 } 196 } 197 198 void 199 __thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m) 200 { 201 notify_.push_back(pair<condition_variable*, mutex*>(cv, m)); 202 } 203 204 void 205 __thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s) 206 { 207 async_states_.push_back(__s); 208 __s->__add_shared(); 209 } 210 211 // __thread_struct 212 213 __thread_struct::__thread_struct() 214 : __p_(new __thread_struct_imp) 215 { 216 } 217 218 __thread_struct::~__thread_struct() 219 { 220 delete __p_; 221 } 222 223 void 224 __thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m) 225 { 226 __p_->notify_all_at_thread_exit(cv, m); 227 } 228 229 void 230 __thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s) 231 { 232 __p_->__make_ready_at_thread_exit(__s); 233 } 234 235 _LIBCPP_END_NAMESPACE_STD 236 237 #endif // !_LIBCPP_HAS_NO_THREADS 238