1 //===------------------------- thread.cpp----------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "__config" 10 #ifndef _LIBCPP_HAS_NO_THREADS 11 12 #include "thread" 13 #include "exception" 14 #include "vector" 15 #include "future" 16 #include "limits" 17 18 #if __has_include(<sys/types.h>) 19 # include <sys/types.h> 20 #endif 21 22 #if __has_include(<sys/param.h>) 23 # include <sys/param.h> 24 #endif 25 26 #if __has_include(<sys/sysctl.h>) 27 # include <sys/sysctl.h> 28 #endif 29 30 #if __has_include(<unistd.h>) 31 # include <unistd.h> 32 #endif 33 34 #if defined(__NetBSD__) 35 #pragma weak pthread_create // Do not create libpthread dependency 36 #endif 37 38 #if defined(_LIBCPP_WIN32API) 39 #include <windows.h> 40 #endif 41 42 #if defined(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB) 43 #pragma comment(lib, "pthread") 44 #endif 45 46 _LIBCPP_BEGIN_NAMESPACE_STD 47 48 thread::~thread() 49 { 50 if (!__libcpp_thread_isnull(&__t_)) 51 terminate(); 52 } 53 54 void 55 thread::join() 56 { 57 int ec = EINVAL; 58 if (!__libcpp_thread_isnull(&__t_)) 59 { 60 ec = __libcpp_thread_join(&__t_); 61 if (ec == 0) 62 __t_ = _LIBCPP_NULL_THREAD; 63 } 64 65 if (ec) 66 __throw_system_error(ec, "thread::join failed"); 67 } 68 69 void 70 thread::detach() 71 { 72 int ec = EINVAL; 73 if (!__libcpp_thread_isnull(&__t_)) 74 { 75 ec = __libcpp_thread_detach(&__t_); 76 if (ec == 0) 77 __t_ = _LIBCPP_NULL_THREAD; 78 } 79 80 if (ec) 81 __throw_system_error(ec, "thread::detach failed"); 82 } 83 84 unsigned 85 thread::hardware_concurrency() _NOEXCEPT 86 { 87 #if defined(CTL_HW) && defined(HW_NCPU) 88 unsigned n; 89 int mib[2] = {CTL_HW, HW_NCPU}; 90 std::size_t s = sizeof(n); 91 sysctl(mib, 2, &n, &s, 0, 0); 92 return n; 93 #elif defined(_SC_NPROCESSORS_ONLN) 94 long result = sysconf(_SC_NPROCESSORS_ONLN); 95 // sysconf returns -1 if the name is invalid, the option does not exist or 96 // does not have a definite limit. 97 // if sysconf returns some other negative number, we have no idea 98 // what is going on. Default to something safe. 99 if (result < 0) 100 return 0; 101 return static_cast<unsigned>(result); 102 #elif defined(_LIBCPP_WIN32API) 103 SYSTEM_INFO info; 104 GetSystemInfo(&info); 105 return info.dwNumberOfProcessors; 106 #else // defined(CTL_HW) && defined(HW_NCPU) 107 // TODO: grovel through /proc or check cpuid on x86 and similar 108 // instructions on other architectures. 109 # if defined(_LIBCPP_WARNING) 110 _LIBCPP_WARNING("hardware_concurrency not yet implemented") 111 # else 112 # warning hardware_concurrency not yet implemented 113 # endif 114 return 0; // Means not computable [thread.thread.static] 115 #endif // defined(CTL_HW) && defined(HW_NCPU) 116 } 117 118 namespace this_thread 119 { 120 121 void 122 sleep_for(const chrono::nanoseconds& ns) 123 { 124 if (ns > chrono::nanoseconds::zero()) 125 { 126 __libcpp_thread_sleep_for(ns); 127 } 128 } 129 130 } // this_thread 131 132 __thread_specific_ptr<__thread_struct>& 133 __thread_local_data() 134 { 135 static __thread_specific_ptr<__thread_struct> __p; 136 return __p; 137 } 138 139 // __thread_struct_imp 140 141 template <class T> 142 class _LIBCPP_HIDDEN __hidden_allocator 143 { 144 public: 145 typedef T value_type; 146 147 T* allocate(size_t __n) 148 {return static_cast<T*>(::operator new(__n * sizeof(T)));} 149 void deallocate(T* __p, size_t) {::operator delete(static_cast<void*>(__p));} 150 151 size_t max_size() const {return size_t(~0) / sizeof(T);} 152 }; 153 154 class _LIBCPP_HIDDEN __thread_struct_imp 155 { 156 typedef vector<__assoc_sub_state*, 157 __hidden_allocator<__assoc_sub_state*> > _AsyncStates; 158 typedef vector<pair<condition_variable*, mutex*>, 159 __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify; 160 161 _AsyncStates async_states_; 162 _Notify notify_; 163 164 __thread_struct_imp(const __thread_struct_imp&); 165 __thread_struct_imp& operator=(const __thread_struct_imp&); 166 public: 167 __thread_struct_imp() {} 168 ~__thread_struct_imp(); 169 170 void notify_all_at_thread_exit(condition_variable* cv, mutex* m); 171 void __make_ready_at_thread_exit(__assoc_sub_state* __s); 172 }; 173 174 __thread_struct_imp::~__thread_struct_imp() 175 { 176 for (_Notify::iterator i = notify_.begin(), e = notify_.end(); 177 i != e; ++i) 178 { 179 i->second->unlock(); 180 i->first->notify_all(); 181 } 182 for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end(); 183 i != e; ++i) 184 { 185 (*i)->__make_ready(); 186 (*i)->__release_shared(); 187 } 188 } 189 190 void 191 __thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m) 192 { 193 notify_.push_back(pair<condition_variable*, mutex*>(cv, m)); 194 } 195 196 void 197 __thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s) 198 { 199 async_states_.push_back(__s); 200 __s->__add_shared(); 201 } 202 203 // __thread_struct 204 205 __thread_struct::__thread_struct() 206 : __p_(new __thread_struct_imp) 207 { 208 } 209 210 __thread_struct::~__thread_struct() 211 { 212 delete __p_; 213 } 214 215 void 216 __thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m) 217 { 218 __p_->notify_all_at_thread_exit(cv, m); 219 } 220 221 void 222 __thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s) 223 { 224 __p_->__make_ready_at_thread_exit(__s); 225 } 226 227 _LIBCPP_END_NAMESPACE_STD 228 229 #endif // !_LIBCPP_HAS_NO_THREADS 230