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