1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___THREAD_THREAD_H 11 #define _LIBCPP___THREAD_THREAD_H 12 13 #include <__assert> 14 #include <__condition_variable/condition_variable.h> 15 #include <__config> 16 #include <__exception/terminate.h> 17 #include <__functional/hash.h> 18 #include <__functional/unary_function.h> 19 #include <__locale> 20 #include <__memory/addressof.h> 21 #include <__memory/unique_ptr.h> 22 #include <__mutex/mutex.h> 23 #include <__system_error/throw_system_error.h> 24 #include <__thread/id.h> 25 #include <__thread/support.h> 26 #include <__type_traits/decay.h> 27 #include <__type_traits/enable_if.h> 28 #include <__type_traits/is_same.h> 29 #include <__type_traits/remove_cvref.h> 30 #include <__utility/forward.h> 31 #include <tuple> 32 33 #if _LIBCPP_HAS_LOCALIZATION 34 # include <sstream> 35 #endif 36 37 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 38 # pragma GCC system_header 39 #endif 40 41 _LIBCPP_PUSH_MACROS 42 #include <__undef_macros> 43 44 _LIBCPP_BEGIN_NAMESPACE_STD 45 46 #if _LIBCPP_HAS_THREADS 47 48 template <class _Tp> 49 class __thread_specific_ptr; 50 class _LIBCPP_EXPORTED_FROM_ABI __thread_struct; 51 class _LIBCPP_HIDDEN __thread_struct_imp; 52 class __assoc_sub_state; 53 54 _LIBCPP_EXPORTED_FROM_ABI __thread_specific_ptr<__thread_struct>& __thread_local_data(); 55 56 class _LIBCPP_EXPORTED_FROM_ABI __thread_struct { 57 __thread_struct_imp* __p_; 58 59 __thread_struct(const __thread_struct&); 60 __thread_struct& operator=(const __thread_struct&); 61 62 public: 63 __thread_struct(); 64 ~__thread_struct(); 65 66 void notify_all_at_thread_exit(condition_variable*, mutex*); 67 void __make_ready_at_thread_exit(__assoc_sub_state*); 68 }; 69 70 template <class _Tp> 71 class __thread_specific_ptr { 72 __libcpp_tls_key __key_; 73 74 // Only __thread_local_data() may construct a __thread_specific_ptr 75 // and only with _Tp == __thread_struct. 76 static_assert(is_same<_Tp, __thread_struct>::value, ""); 77 __thread_specific_ptr(); 78 friend _LIBCPP_EXPORTED_FROM_ABI __thread_specific_ptr<__thread_struct>& __thread_local_data(); 79 80 _LIBCPP_HIDDEN static void _LIBCPP_TLS_DESTRUCTOR_CC __at_thread_exit(void*); 81 82 public: 83 typedef _Tp* pointer; 84 85 __thread_specific_ptr(const __thread_specific_ptr&) = delete; 86 __thread_specific_ptr& operator=(const __thread_specific_ptr&) = delete; 87 ~__thread_specific_ptr(); 88 89 _LIBCPP_HIDE_FROM_ABI pointer get() const { return static_cast<_Tp*>(__libcpp_tls_get(__key_)); } 90 _LIBCPP_HIDE_FROM_ABI pointer operator*() const { return *get(); } 91 _LIBCPP_HIDE_FROM_ABI pointer operator->() const { return get(); } 92 void set_pointer(pointer __p); 93 }; 94 95 template <class _Tp> 96 void _LIBCPP_TLS_DESTRUCTOR_CC __thread_specific_ptr<_Tp>::__at_thread_exit(void* __p) { 97 delete static_cast<pointer>(__p); 98 } 99 100 template <class _Tp> 101 __thread_specific_ptr<_Tp>::__thread_specific_ptr() { 102 int __ec = __libcpp_tls_create(&__key_, &__thread_specific_ptr::__at_thread_exit); 103 if (__ec) 104 std::__throw_system_error(__ec, "__thread_specific_ptr construction failed"); 105 } 106 107 template <class _Tp> 108 __thread_specific_ptr<_Tp>::~__thread_specific_ptr() { 109 // __thread_specific_ptr is only created with a static storage duration 110 // so this destructor is only invoked during program termination. Invoking 111 // pthread_key_delete(__key_) may prevent other threads from deleting their 112 // thread local data. For this reason we leak the key. 113 } 114 115 template <class _Tp> 116 void __thread_specific_ptr<_Tp>::set_pointer(pointer __p) { 117 _LIBCPP_ASSERT_INTERNAL(get() == nullptr, "Attempting to overwrite thread local data"); 118 std::__libcpp_tls_set(__key_, __p); 119 } 120 121 template <> 122 struct hash<__thread_id> : public __unary_function<__thread_id, size_t> { 123 _LIBCPP_HIDE_FROM_ABI size_t operator()(__thread_id __v) const _NOEXCEPT { 124 return hash<__libcpp_thread_id>()(__v.__id_); 125 } 126 }; 127 128 # if _LIBCPP_HAS_LOCALIZATION 129 template <class _CharT, class _Traits> 130 _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& 131 operator<<(basic_ostream<_CharT, _Traits>& __os, __thread_id __id) { 132 // [thread.thread.id]/9 133 // Effects: Inserts the text representation for charT of id into out. 134 // 135 // [thread.thread.id]/2 136 // The text representation for the character type charT of an 137 // object of type thread::id is an unspecified sequence of charT 138 // such that, for two objects of type thread::id x and y, if 139 // x == y is true, the thread::id objects have the same text 140 // representation, and if x != y is true, the thread::id objects 141 // have distinct text representations. 142 // 143 // Since various flags in the output stream can affect how the 144 // thread id is represented (e.g. numpunct or showbase), we 145 // use a temporary stream instead and just output the thread 146 // id representation as a string. 147 148 basic_ostringstream<_CharT, _Traits> __sstr; 149 __sstr.imbue(locale::classic()); 150 __sstr << __id.__id_; 151 return __os << __sstr.str(); 152 } 153 # endif // _LIBCPP_HAS_LOCALIZATION 154 155 # ifndef _LIBCPP_CXX03_LANG 156 157 template <class _TSp, class _Fp, class... _Args, size_t... _Indices> 158 inline _LIBCPP_HIDE_FROM_ABI void __thread_execute(tuple<_TSp, _Fp, _Args...>& __t, __tuple_indices<_Indices...>) { 159 std::__invoke(std::move(std::get<1>(__t)), std::move(std::get<_Indices>(__t))...); 160 } 161 162 template <class _Fp> 163 _LIBCPP_HIDE_FROM_ABI void* __thread_proxy(void* __vp) { 164 // _Fp = tuple< unique_ptr<__thread_struct>, Functor, Args...> 165 unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp)); 166 __thread_local_data().set_pointer(std::get<0>(*__p.get()).release()); 167 typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 2>::type _Index; 168 std::__thread_execute(*__p.get(), _Index()); 169 return nullptr; 170 } 171 172 # else // _LIBCPP_CXX03_LANG 173 174 template <class _Fp> 175 struct __thread_invoke_pair { 176 // This type is used to pass memory for thread local storage and a functor 177 // to a newly created thread because std::pair doesn't work with 178 // std::unique_ptr in C++03. 179 _LIBCPP_HIDE_FROM_ABI __thread_invoke_pair(_Fp& __f) : __tsp_(new __thread_struct), __fn_(__f) {} 180 unique_ptr<__thread_struct> __tsp_; 181 _Fp __fn_; 182 }; 183 184 template <class _Fp> 185 _LIBCPP_HIDE_FROM_ABI void* __thread_proxy_cxx03(void* __vp) { 186 unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp)); 187 __thread_local_data().set_pointer(__p->__tsp_.release()); 188 (__p->__fn_)(); 189 return nullptr; 190 } 191 192 # endif // _LIBCPP_CXX03_LANG 193 194 class _LIBCPP_EXPORTED_FROM_ABI thread { 195 __libcpp_thread_t __t_; 196 197 thread(const thread&); 198 thread& operator=(const thread&); 199 200 public: 201 typedef __thread_id id; 202 typedef __libcpp_thread_t native_handle_type; 203 204 _LIBCPP_HIDE_FROM_ABI thread() _NOEXCEPT : __t_(_LIBCPP_NULL_THREAD) {} 205 206 # ifndef _LIBCPP_CXX03_LANG 207 template <class _Fp, class... _Args, __enable_if_t<!is_same<__remove_cvref_t<_Fp>, thread>::value, int> = 0> 208 _LIBCPP_HIDE_FROM_ABI explicit thread(_Fp&& __f, _Args&&... __args) { 209 typedef unique_ptr<__thread_struct> _TSPtr; 210 _TSPtr __tsp(new __thread_struct); 211 typedef tuple<_TSPtr, __decay_t<_Fp>, __decay_t<_Args>...> _Gp; 212 unique_ptr<_Gp> __p(new _Gp(std::move(__tsp), std::forward<_Fp>(__f), std::forward<_Args>(__args)...)); 213 int __ec = std::__libcpp_thread_create(&__t_, std::addressof(__thread_proxy<_Gp>), __p.get()); 214 if (__ec == 0) 215 __p.release(); 216 else 217 __throw_system_error(__ec, "thread constructor failed"); 218 } 219 # else // _LIBCPP_CXX03_LANG 220 template <class _Fp> 221 _LIBCPP_HIDE_FROM_ABI explicit thread(_Fp __f) { 222 typedef __thread_invoke_pair<_Fp> _InvokePair; 223 typedef unique_ptr<_InvokePair> _PairPtr; 224 _PairPtr __pp(new _InvokePair(__f)); 225 int __ec = std::__libcpp_thread_create(&__t_, &__thread_proxy_cxx03<_InvokePair>, __pp.get()); 226 if (__ec == 0) 227 __pp.release(); 228 else 229 __throw_system_error(__ec, "thread constructor failed"); 230 } 231 # endif 232 ~thread(); 233 234 _LIBCPP_HIDE_FROM_ABI thread(thread&& __t) _NOEXCEPT : __t_(__t.__t_) { __t.__t_ = _LIBCPP_NULL_THREAD; } 235 236 _LIBCPP_HIDE_FROM_ABI thread& operator=(thread&& __t) _NOEXCEPT { 237 if (!__libcpp_thread_isnull(&__t_)) 238 terminate(); 239 __t_ = __t.__t_; 240 __t.__t_ = _LIBCPP_NULL_THREAD; 241 return *this; 242 } 243 244 _LIBCPP_HIDE_FROM_ABI void swap(thread& __t) _NOEXCEPT { std::swap(__t_, __t.__t_); } 245 246 _LIBCPP_HIDE_FROM_ABI bool joinable() const _NOEXCEPT { return !__libcpp_thread_isnull(&__t_); } 247 void join(); 248 void detach(); 249 _LIBCPP_HIDE_FROM_ABI id get_id() const _NOEXCEPT { return __libcpp_thread_get_id(&__t_); } 250 _LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() _NOEXCEPT { return __t_; } 251 252 static unsigned hardware_concurrency() _NOEXCEPT; 253 }; 254 255 inline _LIBCPP_HIDE_FROM_ABI void swap(thread& __x, thread& __y) _NOEXCEPT { __x.swap(__y); } 256 257 #endif // _LIBCPP_HAS_THREADS 258 259 _LIBCPP_END_NAMESPACE_STD 260 261 _LIBCPP_POP_MACROS 262 263 #endif // _LIBCPP___THREAD_THREAD_H 264