1 //===------------------------- thread.cpp----------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "thread" 11 #include "exception" 12 #include "vector" 13 #include "future" 14 #include "limits" 15 #include <sys/types.h> 16 #if !defined(_WIN32) 17 #if !defined(__sun__) && !defined(__linux__) 18 #include <sys/sysctl.h> 19 #else 20 #include <unistd.h> 21 #endif // !__sun__ && !__linux__ 22 #endif // !_WIN32 23 24 _LIBCPP_BEGIN_NAMESPACE_STD 25 26 thread::~thread() 27 { 28 if (__t_ != 0) 29 terminate(); 30 } 31 32 void 33 thread::join() 34 { 35 int ec = pthread_join(__t_, 0); 36 #ifndef _LIBCPP_NO_EXCEPTIONS 37 if (ec) 38 throw system_error(error_code(ec, system_category()), "thread::join failed"); 39 #endif // _LIBCPP_NO_EXCEPTIONS 40 __t_ = 0; 41 } 42 43 void 44 thread::detach() 45 { 46 int ec = EINVAL; 47 if (__t_ != 0) 48 { 49 ec = pthread_detach(__t_); 50 if (ec == 0) 51 __t_ = 0; 52 } 53 #ifndef _LIBCPP_NO_EXCEPTIONS 54 if (ec) 55 throw system_error(error_code(ec, system_category()), "thread::detach failed"); 56 #endif // _LIBCPP_NO_EXCEPTIONS 57 } 58 59 unsigned 60 thread::hardware_concurrency() _NOEXCEPT 61 { 62 #if defined(CTL_HW) && defined(HW_NCPU) 63 unsigned n; 64 int mib[2] = {CTL_HW, HW_NCPU}; 65 std::size_t s = sizeof(n); 66 sysctl(mib, 2, &n, &s, 0, 0); 67 return n; 68 #elif defined(_POSIX_C_SOURCE) && (_POSIX_C_SOURCE >= 200112L) && defined(_SC_NPROCESSORS_ONLN) 69 long result = sysconf(_SC_NPROCESSORS_ONLN); 70 // sysconf returns -1 if the name is invalid, the option does not exist or 71 // does not have a definite limit. 72 // if sysconf returns some other negative number, we have no idea 73 // what is going on. Default to something safe. 74 if (result < 0) 75 return 0; 76 return static_cast<unsigned>(result); 77 #else // defined(CTL_HW) && defined(HW_NCPU) 78 // TODO: grovel through /proc or check cpuid on x86 and similar 79 // instructions on other architectures. 80 return 0; // Means not computable [thread.thread.static] 81 #endif // defined(CTL_HW) && defined(HW_NCPU) 82 } 83 84 namespace this_thread 85 { 86 87 void 88 sleep_for(const chrono::nanoseconds& ns) 89 { 90 using namespace chrono; 91 if (ns > nanoseconds::zero()) 92 { 93 seconds s = duration_cast<seconds>(ns); 94 timespec ts; 95 typedef decltype(ts.tv_sec) ts_sec; 96 _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max(); 97 if (s.count() < ts_sec_max) 98 { 99 ts.tv_sec = static_cast<ts_sec>(s.count()); 100 ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((ns-s).count()); 101 } 102 else 103 { 104 ts.tv_sec = ts_sec_max; 105 ts.tv_nsec = giga::num - 1; 106 } 107 nanosleep(&ts, 0); 108 } 109 } 110 111 } // this_thread 112 113 __thread_specific_ptr<__thread_struct>& 114 __thread_local_data() 115 { 116 static __thread_specific_ptr<__thread_struct> __p; 117 return __p; 118 } 119 120 // __thread_struct_imp 121 122 template <class T> 123 class _LIBCPP_HIDDEN __hidden_allocator 124 { 125 public: 126 typedef T value_type; 127 128 T* allocate(size_t __n) 129 {return static_cast<T*>(::operator new(__n * sizeof(T)));} 130 void deallocate(T* __p, size_t) {::operator delete((void*)__p);} 131 132 size_t max_size() const {return size_t(~0) / sizeof(T);} 133 }; 134 135 class _LIBCPP_HIDDEN __thread_struct_imp 136 { 137 typedef vector<__assoc_sub_state*, 138 __hidden_allocator<__assoc_sub_state*> > _AsyncStates; 139 typedef vector<pair<condition_variable*, mutex*>, 140 __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify; 141 142 _AsyncStates async_states_; 143 _Notify notify_; 144 145 __thread_struct_imp(const __thread_struct_imp&); 146 __thread_struct_imp& operator=(const __thread_struct_imp&); 147 public: 148 __thread_struct_imp() {} 149 ~__thread_struct_imp(); 150 151 void notify_all_at_thread_exit(condition_variable* cv, mutex* m); 152 void __make_ready_at_thread_exit(__assoc_sub_state* __s); 153 }; 154 155 __thread_struct_imp::~__thread_struct_imp() 156 { 157 for (_Notify::iterator i = notify_.begin(), e = notify_.end(); 158 i != e; ++i) 159 { 160 i->second->unlock(); 161 i->first->notify_all(); 162 } 163 for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end(); 164 i != e; ++i) 165 { 166 (*i)->__make_ready(); 167 (*i)->__release_shared(); 168 } 169 } 170 171 void 172 __thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m) 173 { 174 notify_.push_back(pair<condition_variable*, mutex*>(cv, m)); 175 } 176 177 void 178 __thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s) 179 { 180 async_states_.push_back(__s); 181 __s->__add_shared(); 182 } 183 184 // __thread_struct 185 186 __thread_struct::__thread_struct() 187 : __p_(new __thread_struct_imp) 188 { 189 } 190 191 __thread_struct::~__thread_struct() 192 { 193 delete __p_; 194 } 195 196 void 197 __thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m) 198 { 199 __p_->notify_all_at_thread_exit(cv, m); 200 } 201 202 void 203 __thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s) 204 { 205 __p_->__make_ready_at_thread_exit(__s); 206 } 207 208 _LIBCPP_END_NAMESPACE_STD 209