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