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
40template <class _Tp>
41class __thread_specific_ptr;
42class _LIBCPP_EXPORTED_FROM_ABI __thread_struct;
43class _LIBCPP_HIDDEN __thread_struct_imp;
44class __assoc_sub_state;
45
46_LIBCPP_EXPORTED_FROM_ABI __thread_specific_ptr<__thread_struct>& __thread_local_data();
47
48class _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
54public:
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
62template <class _Tp>
63class __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
74public:
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
87template <class _Tp>
88void _LIBCPP_TLS_DESTRUCTOR_CC __thread_specific_ptr<_Tp>::__at_thread_exit(void* __p) {
89 delete static_cast<pointer>(__p);
90}
91
92template <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
99template <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
107template <class _Tp>
108void __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
113template <>
114struct _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
121template <class _CharT, class _Traits>
122_LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
123operator<<(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
147class _LIBCPP_EXPORTED_FROM_ABI thread {
148 __libcpp_thread_t __t_;
149
150 thread(const thread&);
151 thread& operator=(const thread&);
152
153public:
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
190template <class _TSp, class _Fp, class... _Args, size_t... _Indices>
191inline _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
195template <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
205template <class _Fp, class... _Args, __enable_if_t<!is_same<__remove_cvref_t<_Fp>, thread>::value, int> >
206thread::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
220template <class _Fp>
221struct __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
230template <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
238template <class _Fp>
239thread::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
252inline _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