libcxx

libcxx mirror with random patches
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thread.cpp (5684B)


      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 
     20 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
     21 # include <sys/param.h>
     22 # if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(__APPLE__)
     23 #   include <sys/sysctl.h>
     24 # endif
     25 #endif // defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
     26 
     27 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__CloudABI__) || defined(__Fuchsia__)
     28 # include <unistd.h>
     29 #endif // defined(__unix__) || (defined(__APPLE__) && defined(__MACH__)) || defined(__CloudABI__) || defined(__Fuchsia__)
     30 
     31 #if defined(__NetBSD__)
     32 #pragma weak pthread_create // Do not create libpthread dependency
     33 #endif
     34 
     35 #if defined(_LIBCPP_WIN32API)
     36 #include <windows.h>
     37 #endif
     38 
     39 _LIBCPP_BEGIN_NAMESPACE_STD
     40 
     41 thread::~thread()
     42 {
     43     if (!__libcpp_thread_isnull(&__t_))
     44         terminate();
     45 }
     46 
     47 void
     48 thread::join()
     49 {
     50     int ec = EINVAL;
     51     if (!__libcpp_thread_isnull(&__t_))
     52     {
     53         ec = __libcpp_thread_join(&__t_);
     54         if (ec == 0)
     55             __t_ = _LIBCPP_NULL_THREAD;
     56     }
     57 
     58     if (ec)
     59         __throw_system_error(ec, "thread::join failed");
     60 }
     61 
     62 void
     63 thread::detach()
     64 {
     65     int ec = EINVAL;
     66     if (!__libcpp_thread_isnull(&__t_))
     67     {
     68         ec = __libcpp_thread_detach(&__t_);
     69         if (ec == 0)
     70             __t_ = _LIBCPP_NULL_THREAD;
     71     }
     72 
     73     if (ec)
     74         __throw_system_error(ec, "thread::detach failed");
     75 }
     76 
     77 unsigned
     78 thread::hardware_concurrency() _NOEXCEPT
     79 {
     80 #if defined(CTL_HW) && defined(HW_NCPU)
     81     unsigned n;
     82     int mib[2] = {CTL_HW, HW_NCPU};
     83     std::size_t s = sizeof(n);
     84     sysctl(mib, 2, &n, &s, 0, 0);
     85     return n;
     86 #elif defined(_SC_NPROCESSORS_ONLN)
     87     long result = sysconf(_SC_NPROCESSORS_ONLN);
     88     // sysconf returns -1 if the name is invalid, the option does not exist or
     89     // does not have a definite limit.
     90     // if sysconf returns some other negative number, we have no idea
     91     // what is going on. Default to something safe.
     92     if (result < 0)
     93         return 0;
     94     return static_cast<unsigned>(result);
     95 #elif defined(_LIBCPP_WIN32API)
     96     SYSTEM_INFO info;
     97     GetSystemInfo(&info);
     98     return info.dwNumberOfProcessors;
     99 #elif defined(__vita__)
    100     return 4;
    101 #else  // defined(CTL_HW) && defined(HW_NCPU)
    102     // TODO: grovel through /proc or check cpuid on x86 and similar
    103     // instructions on other architectures.
    104 #   if defined(_LIBCPP_WARNING)
    105         _LIBCPP_WARNING("hardware_concurrency not yet implemented")
    106 #   else
    107 #       warning hardware_concurrency not yet implemented
    108 #   endif
    109     return 0;  // Means not computable [thread.thread.static]
    110 #endif  // defined(CTL_HW) && defined(HW_NCPU)
    111 }
    112 
    113 namespace this_thread
    114 {
    115 
    116 void
    117 sleep_for(const chrono::nanoseconds& ns)
    118 {
    119     if (ns > chrono::nanoseconds::zero())
    120     {
    121         __libcpp_thread_sleep_for(ns);
    122     }
    123 }
    124 
    125 }  // this_thread
    126 
    127 __thread_specific_ptr<__thread_struct>&
    128 __thread_local_data()
    129 {
    130     static __thread_specific_ptr<__thread_struct> __p;
    131     return __p;
    132 }
    133 
    134 // __thread_struct_imp
    135 
    136 template <class T>
    137 class _LIBCPP_HIDDEN __hidden_allocator
    138 {
    139 public:
    140     typedef T  value_type;
    141 
    142     T* allocate(size_t __n)
    143         {return static_cast<T*>(::operator new(__n * sizeof(T)));}
    144     void deallocate(T* __p, size_t) {::operator delete(static_cast<void*>(__p));}
    145 
    146     size_t max_size() const {return size_t(~0) / sizeof(T);}
    147 };
    148 
    149 class _LIBCPP_HIDDEN __thread_struct_imp
    150 {
    151     typedef vector<__assoc_sub_state*,
    152                           __hidden_allocator<__assoc_sub_state*> > _AsyncStates;
    153     typedef vector<pair<condition_variable*, mutex*>,
    154                __hidden_allocator<pair<condition_variable*, mutex*> > > _Notify;
    155 
    156     _AsyncStates async_states_;
    157     _Notify notify_;
    158 
    159     __thread_struct_imp(const __thread_struct_imp&);
    160     __thread_struct_imp& operator=(const __thread_struct_imp&);
    161 public:
    162     __thread_struct_imp() {}
    163     ~__thread_struct_imp();
    164 
    165     void notify_all_at_thread_exit(condition_variable* cv, mutex* m);
    166     void __make_ready_at_thread_exit(__assoc_sub_state* __s);
    167 };
    168 
    169 __thread_struct_imp::~__thread_struct_imp()
    170 {
    171     for (_Notify::iterator i = notify_.begin(), e = notify_.end();
    172             i != e; ++i)
    173     {
    174         i->second->unlock();
    175         i->first->notify_all();
    176     }
    177     for (_AsyncStates::iterator i = async_states_.begin(), e = async_states_.end();
    178             i != e; ++i)
    179     {
    180         (*i)->__make_ready();
    181         (*i)->__release_shared();
    182     }
    183 }
    184 
    185 void
    186 __thread_struct_imp::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
    187 {
    188     notify_.push_back(pair<condition_variable*, mutex*>(cv, m));
    189 }
    190 
    191 void
    192 __thread_struct_imp::__make_ready_at_thread_exit(__assoc_sub_state* __s)
    193 {
    194     async_states_.push_back(__s);
    195     __s->__add_shared();
    196 }
    197 
    198 // __thread_struct
    199 
    200 __thread_struct::__thread_struct()
    201     : __p_(new __thread_struct_imp)
    202 {
    203 }
    204 
    205 __thread_struct::~__thread_struct()
    206 {
    207     delete __p_;
    208 }
    209 
    210 void
    211 __thread_struct::notify_all_at_thread_exit(condition_variable* cv, mutex* m)
    212 {
    213     __p_->notify_all_at_thread_exit(cv, m);
    214 }
    215 
    216 void
    217 __thread_struct::__make_ready_at_thread_exit(__assoc_sub_state* __s)
    218 {
    219     __p_->__make_ready_at_thread_exit(__s);
    220 }
    221 
    222 _LIBCPP_END_NAMESPACE_STD
    223 
    224 #endif // !_LIBCPP_HAS_NO_THREADS