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