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