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__) || defined(__wasi__)
27# include <unistd.h>
28#endif // defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__CloudABI__) || defined(__Fuchsia__) || defined(__wasi__)
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#if defined(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB)
39#pragma comment(lib, "pthread")
40#endif
41
42_LIBCPP_BEGIN_NAMESPACE_STD
43
44thread::~thread()
45{
46 if (!__libcpp_thread_isnull(&__t_))
47 terminate();
48}
49
50void
51thread::join()
52{
53 int ec = EINVAL;
54 if (!__libcpp_thread_isnull(&__t_))
55 {
56 ec = __libcpp_thread_join(&__t_);
57 if (ec == 0)
58 __t_ = _LIBCPP_NULL_THREAD;
59 }
60
61 if (ec)
62 __throw_system_error(ec, "thread::join failed");
63}
64
65void
66thread::detach()
67{
68 int ec = EINVAL;
69 if (!__libcpp_thread_isnull(&__t_))
70 {
71 ec = __libcpp_thread_detach(&__t_);
72 if (ec == 0)
73 __t_ = _LIBCPP_NULL_THREAD;
74 }
75
76 if (ec)
77 __throw_system_error(ec, "thread::detach failed");
78}
79
80unsigned
81thread::hardware_concurrency() _NOEXCEPT
82{
83#if defined(CTL_HW) && defined(HW_NCPU)
84 unsigned n;
85 int mib[2] = {CTL_HW, HW_NCPU};
86 std::size_t s = sizeof(n);
87 sysctl(mib, 2, &n, &s, 0, 0);
88 return n;
89#elif defined(_SC_NPROCESSORS_ONLN)
90 long result = sysconf(_SC_NPROCESSORS_ONLN);
91 // sysconf returns -1 if the name is invalid, the option does not exist or
92 // does not have a definite limit.
93 // if sysconf returns some other negative number, we have no idea
94 // what is going on. Default to something safe.
95 if (result < 0)
96 return 0;
97 return static_cast<unsigned>(result);
98#elif defined(_LIBCPP_WIN32API)
99 SYSTEM_INFO info;
100 GetSystemInfo(&info);
101 return info.dwNumberOfProcessors;
102#else // defined(CTL_HW) && defined(HW_NCPU)
103 // TODO: grovel through /proc or check cpuid on x86 and similar
104 // instructions on other architectures.
105# if defined(_LIBCPP_WARNING)
106 _LIBCPP_WARNING("hardware_concurrency not yet implemented")
107# else
108# warning hardware_concurrency not yet implemented
109# endif
110 return 0; // Means not computable [thread.thread.static]
111#endif // defined(CTL_HW) && defined(HW_NCPU)
112}
113
114namespace this_thread
115{
116
117void
118sleep_for(const chrono::nanoseconds& ns)
119{
120 if (ns > chrono::nanoseconds::zero())
121 {
122 __libcpp_thread_sleep_for(ns);
123 }
124}
125
126} // this_thread
127
128__thread_specific_ptr<__thread_struct>&
129__thread_local_data()
130{
131 static __thread_specific_ptr<__thread_struct> __p;
132 return __p;
133}
134
135// __thread_struct_imp
136
137template <class T>
138class _LIBCPP_HIDDEN __hidden_allocator
139{
140public:
141 typedef T value_type;
142
143 T* allocate(size_t __n)
144 {return static_cast<T*>(::operator new(__n * sizeof(T)));}
145 void deallocate(T* __p, size_t) {::operator delete(static_cast<void*>(__p));}
146
147 size_t max_size() const {return size_t(~0) / sizeof(T);}
148};
149
150class _LIBCPP_HIDDEN __thread_struct_imp
151{
152 typedef vector<__assoc_sub_state*,
153 __hidden_allocator<__assoc_sub_state*> > _AsyncStates;
154 typedef vector<pair<condition_variable*, mutex*>,
155 __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify;
156
157 _AsyncStates async_states_;
158 _Notify notify_;
159
160 __thread_struct_imp(const __thread_struct_imp&);
161 __thread_struct_imp& operator=(const __thread_struct_imp&);
162public:
163 __thread_struct_imp() {}
164 ~__thread_struct_imp();
165
166 void notify_all_at_thread_exit(condition_variable* cv, mutex* m);
167 void __make_ready_at_thread_exit(__assoc_sub_state* __s);
168};
169
170__thread_struct_imp::~__thread_struct_imp()
171{
172 for (_Notify::iterator i = notify_.begin(), e = notify_.end();
173 i != e; ++i)
174 {
175 i->second->unlock();
176 i->first->notify_all();
177 }
178 for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end();
179 i != e; ++i)
180 {
181 (*i)->__make_ready();
182 (*i)->__release_shared();
183 }
184}
185
186void
187__thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
188{
189 notify_.push_back(pair<condition_variable*, mutex*>(cv, m));
190}
191
192void
193__thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s)
194{
195 async_states_.push_back(__s);
196 __s->__add_shared();
197}
198
199// __thread_struct
200
201__thread_struct::__thread_struct()
202 : __p_(new __thread_struct_imp)
203{
204}
205
206__thread_struct::~__thread_struct()
207{
208 delete __p_;
209}
210
211void
212__thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
213{
214 __p_->notify_all_at_thread_exit(cv, m);
215}
216
217void
218__thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s)
219{
220 __p_->__make_ready_at_thread_exit(__s);
221}
222
223_LIBCPP_END_NAMESPACE_STD
224
225#endif // !_LIBCPP_HAS_NO_THREADS
226