external/bsd/libc++/dist/libcxx/src/thread.cpp

   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 "__config"
  11 #ifndef _LIBCPP_HAS_NO_THREADS
  12
  13 #include "thread"
  14 #include "exception"
  15 #include "vector"
  16 #include "future"
  17 #include "limits"
  18 #include <sys/types.h>
  19 #if !defined(_WIN32)
  20 # if !defined(__sun__) && !defined(__linux__) && !defined(_AIX) && !defined(__native_client__) && !defined(__CloudABI__)
  21 #   include <sys/sysctl.h>
  22 # endif // !defined(__sun__) && !defined(__linux__) && !defined(_AIX) && !defined(__native_client__) && !defined(__CloudABI__)
  23 # include <unistd.h>
  24 #endif // !_WIN32
  25
  26 #if defined(__NetBSD__) || defined(__minix)
  27 #pragma weak pthread_create // Do not create libpthread dependency
  28 #endif
  29 #if defined(_WIN32)
  30 #include <windows.h>
  31 #endif
  32
  33 _LIBCPP_BEGIN_NAMESPACE_STD
  34
  35 thread::~thread()
  36 {
  37     if (__t_ != 0)
  38         terminate();
  39 }
  40
  41 void
  42 thread::join()
  43 {
  44     int ec = pthread_join(__t_, 0);
  45 #ifndef _LIBCPP_NO_EXCEPTIONS
  46     if (ec)
  47         throw system_error(error_code(ec, system_category()), "thread::join failed");
  48 #else
  49     (void)ec;
  50 #endif  // _LIBCPP_NO_EXCEPTIONS
  51     __t_ = 0;
  52 }
  53
  54 void
  55 thread::detach()
  56 {
  57     int ec = EINVAL;
  58     if (__t_ != 0)
  59     {
  60         ec = pthread_detach(__t_);
  61         if (ec == 0)
  62             __t_ = 0;
  63     }
  64 #ifndef _LIBCPP_NO_EXCEPTIONS
  65     if (ec)
  66         throw system_error(error_code(ec, system_category()), "thread::detach failed");
  67 #endif  // _LIBCPP_NO_EXCEPTIONS
  68 }
  69
  70 unsigned
  71 thread::hardware_concurrency() _NOEXCEPT
  72 {
  73 #if defined(CTL_HW) && defined(HW_NCPU)
  74     unsigned n;
  75     int mib[2] = {CTL_HW, HW_NCPU};
  76     std::size_t s = sizeof(n);
  77     sysctl(mib, 2, &n, &s, 0, 0);
  78     return n;
  79 #elif defined(_SC_NPROCESSORS_ONLN)
  80     long result = sysconf(_SC_NPROCESSORS_ONLN);
  81     // sysconf returns -1 if the name is invalid, the option does not exist or
  82     // does not have a definite limit.
  83     // if sysconf returns some other negative number, we have no idea
  84     // what is going on. Default to something safe.
  85     if (result < 0)
  86         return 0;
  87     return static_cast<unsigned>(result);
  88 #elif defined(_WIN32)
  89     SYSTEM_INFO info;
  90     GetSystemInfo(&info);
  91     return info.dwNumberOfProcessors;
  92 #else  // defined(CTL_HW) && defined(HW_NCPU)
  93     // TODO: grovel through /proc or check cpuid on x86 and similar
  94     // instructions on other architectures.
  95 #   if defined(_MSC_VER) && ! defined(__clang__)
  96         _LIBCPP_WARNING("hardware_concurrency not yet implemented")
  97 #   else
  98 #       warning hardware_concurrency not yet implemented
  99 #   endif
 100     return 0;  // Means not computable [thread.thread.static]
 101 #endif  // defined(CTL_HW) && defined(HW_NCPU)
 102 }
 103
 104 namespace this_thread
 105 {
 106
 107 void
 108 sleep_for(const chrono::nanoseconds& ns)
 109 {
 110     using namespace chrono;
 111     if (ns > nanoseconds::zero())
 112     {
 113         seconds s = duration_cast<seconds>(ns);
 114         timespec ts;
 115         typedef decltype(ts.tv_sec) ts_sec;
 116         _LIBCPP_CONSTEXPR ts_sec ts_sec_max = numeric_limits<ts_sec>::max();
 117         if (s.count() < ts_sec_max)
 118         {
 119             ts.tv_sec = static_cast<ts_sec>(s.count());
 120             ts.tv_nsec = static_cast<decltype(ts.tv_nsec)>((ns-s).count());
 121         }
 122         else
 123         {
 124             ts.tv_sec = ts_sec_max;
 125             ts.tv_nsec = giga::num - 1;
 126         }
 127
 128         while (nanosleep(&ts, &ts) == -1 && errno == EINTR)
 129             ;
 130     }
 131 }
 132
 133 }  // this_thread
 134
 135 __thread_specific_ptr<__thread_struct>&
 136 __thread_local_data()
 137 {
 138     static __thread_specific_ptr<__thread_struct> __p;
 139     return __p;
 140 }
 141
 142 // __thread_struct_imp
 143
 144 template <class T>
 145 class _LIBCPP_HIDDEN __hidden_allocator
 146 {
 147 public:
 148     typedef T  value_type;
 149
 150     T* allocate(size_t __n)
 151         {return static_cast<T*>(::operator new(__n * sizeof(T)));}
 152     void deallocate(T* __p, size_t) {::operator delete(static_cast<void*>(__p));}
 153
 154     size_t max_size() const {return size_t(~0) / sizeof(T);}
 155 };
 156
 157 class _LIBCPP_HIDDEN __thread_struct_imp
 158 {
 159     typedef vector<__assoc_sub_state*,
 160                           __hidden_allocator<__assoc_sub_state*> > _AsyncStates;
 161     typedef vector<pair<condition_variable*, mutex*>,
 162                __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify;
 163
 164     _AsyncStates async_states_;
 165     _Notify notify_;
 166
 167     __thread_struct_imp(const __thread_struct_imp&);
 168     __thread_struct_imp& operator=(const __thread_struct_imp&);
 169 public:
 170     __thread_struct_imp() {}
 171     ~__thread_struct_imp();
 172
 173     void notify_all_at_thread_exit(condition_variable* cv, mutex* m);
 174     void __make_ready_at_thread_exit(__assoc_sub_state* __s);
 175 };
 176
 177 __thread_struct_imp::~__thread_struct_imp()
 178 {
 179     for (_Notify::iterator i = notify_.begin(), e = notify_.end();
 180             i != e; ++i)
 181     {
 182         i->second->unlock();
 183         i->first->notify_all();
 184     }
 185     for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end();
 186             i != e; ++i)
 187     {
 188         (*i)->__make_ready();
 189         (*i)->__release_shared();
 190     }
 191 }
 192
 193 void
 194 __thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
 195 {
 196     notify_.push_back(pair<condition_variable*, mutex*>(cv, m));
 197 }
 198
 199 void
 200 __thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s)
 201 {
 202     async_states_.push_back(__s);
 203     __s->__add_shared();
 204 }
 205
 206 // __thread_struct
 207
 208 __thread_struct::__thread_struct()
 209     : __p_(new __thread_struct_imp)
 210 {
 211 }
 212
 213 __thread_struct::~__thread_struct()
 214 {
 215     delete __p_;
 216 }
 217
 218 void
 219 __thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
 220 {
 221     __p_->notify_all_at_thread_exit(cv, m);
 222 }
 223
 224 void
 225 __thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s)
 226 {
 227     __p_->__make_ready_at_thread_exit(__s);
 228 }
 229
 230 _LIBCPP_END_NAMESPACE_STD
 231
 232 #endif // !_LIBCPP_HAS_NO_THREADS