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