libstdc++-v3/include/std/thread

   1 // <thread> -*- C++ -*-
   2
   3 // Copyright (C) 2008-2014 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /** @file include/thread
  26  *  This is a Standard C++ Library header.
  27  */
  28
  29 #ifndef _GLIBCXX_THREAD
  30 #define _GLIBCXX_THREAD 1
  31
  32 #pragma GCC system_header
  33
  34 #if __cplusplus < 201103L
  35 # include <bits/c++0x_warning.h>
  36 #else
  37
  38 #include <chrono>
  39 #include <functional>
  40 #include <memory>
  41 #include <bits/functexcept.h>
  42 #include <bits/functional_hash.h>
  43 #include <bits/gthr.h>
  44
  45 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
  46
  47 namespace std _GLIBCXX_VISIBILITY(default)
  48 {
  49 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  50
  51   /**
  52    * @defgroup threads Threads
  53    * @ingroup concurrency
  54    *
  55    * Classes for thread support.
  56    * @{
  57    */
  58
  59   /// thread
  60   class thread
  61   {
  62   public:
  63     typedef __gthread_t                 native_handle_type;
  64     struct _Impl_base;
  65     typedef shared_ptr<_Impl_base>      __shared_base_type;
  66
  67     /// thread::id
  68     class id
  69     {
  70       native_handle_type        _M_thread;
  71
  72     public:
  73       id() noexcept : _M_thread() { }
  74
  75       explicit
  76       id(native_handle_type __id) : _M_thread(__id) { }
  77
  78     private:
  79       friend class thread;
  80       friend class hash<thread::id>;
  81
  82       friend bool
  83       operator==(thread::id __x, thread::id __y) noexcept
  84       { return __gthread_equal(__x._M_thread, __y._M_thread); }
  85
  86       friend bool
  87       operator<(thread::id __x, thread::id __y) noexcept
  88       { return __x._M_thread < __y._M_thread; }
  89
  90       template<class _CharT, class _Traits>
  91         friend basic_ostream<_CharT, _Traits>&
  92         operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id);
  93     };
  94
  95     // Simple base type that the templatized, derived class containing
  96     // an arbitrary functor can be converted to and called.
  97     struct _Impl_base
  98     {
  99       __shared_base_type        _M_this_ptr;
 100
 101       inline virtual ~_Impl_base();
 102
 103       virtual void _M_run() = 0;
 104     };
 105
 106     template<typename _Callable>
 107       struct _Impl : public _Impl_base
 108       {
 109         _Callable               _M_func;
 110
 111         _Impl(_Callable&& __f) : _M_func(std::forward<_Callable>(__f))
 112         { }
 113
 114         void
 115         _M_run() { _M_func(); }
 116       };
 117
 118   private:
 119     id                          _M_id;
 120
 121   public:
 122     thread() noexcept = default;
 123     // _GLIBCXX_RESOLVE_LIB_DEFECTS
 124     // 2097.  packaged_task constructors should be constrained
 125     thread(thread&) = delete;
 126     thread(const thread&) = delete;
 127
 128     thread(thread&& __t) noexcept
 129     { swap(__t); }
 130
 131     template<typename _Callable, typename... _Args>
 132       explicit
 133       thread(_Callable&& __f, _Args&&... __args)
 134       {
 135 #ifdef GTHR_ACTIVE_PROXY
 136         // Create a reference to pthread_create, not just the gthr weak symbol
 137         _M_start_thread(_M_make_routine(std::__bind_simple(
 138                 std::forward<_Callable>(__f),
 139                 std::forward<_Args>(__args)...)),
 140             reinterpret_cast<void(*)()>(&pthread_create));
 141 #else
 142         _M_start_thread(_M_make_routine(std::__bind_simple(
 143                 std::forward<_Callable>(__f),
 144                 std::forward<_Args>(__args)...)));
 145 #endif
 146       }
 147
 148     ~thread()
 149     {
 150       if (joinable())
 151         std::terminate();
 152     }
 153
 154     thread& operator=(const thread&) = delete;
 155
 156     thread& operator=(thread&& __t) noexcept
 157     {
 158       if (joinable())
 159         std::terminate();
 160       swap(__t);
 161       return *this;
 162     }
 163
 164     void
 165     swap(thread& __t) noexcept
 166     { std::swap(_M_id, __t._M_id); }
 167
 168     bool
 169     joinable() const noexcept
 170     { return !(_M_id == id()); }
 171
 172     void
 173     join();
 174
 175     void
 176     detach();
 177
 178     thread::id
 179     get_id() const noexcept
 180     { return _M_id; }
 181
 182     /** @pre thread is joinable
 183      */
 184     native_handle_type
 185     native_handle()
 186     { return _M_id._M_thread; }
 187
 188     // Returns a value that hints at the number of hardware thread contexts.
 189     static unsigned int
 190     hardware_concurrency() noexcept;
 191
 192   private:
 193     void
 194     _M_start_thread(__shared_base_type, void (*)());
 195
 196     void
 197     _M_start_thread(__shared_base_type);
 198
 199     template<typename _Callable>
 200       shared_ptr<_Impl<_Callable>>
 201       _M_make_routine(_Callable&& __f)
 202       {
 203         // Create and allocate full data structure, not base.
 204         return std::make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
 205       }
 206   };
 207
 208   inline thread::_Impl_base::~_Impl_base() = default;
 209
 210   inline void
 211   swap(thread& __x, thread& __y) noexcept
 212   { __x.swap(__y); }
 213
 214   inline bool
 215   operator!=(thread::id __x, thread::id __y) noexcept
 216   { return !(__x == __y); }
 217
 218   inline bool
 219   operator<=(thread::id __x, thread::id __y) noexcept
 220   { return !(__y < __x); }
 221
 222   inline bool
 223   operator>(thread::id __x, thread::id __y) noexcept
 224   { return __y < __x; }
 225
 226   inline bool
 227   operator>=(thread::id __x, thread::id __y) noexcept
 228   { return !(__x < __y); }
 229
 230   // DR 889.
 231   /// std::hash specialization for thread::id.
 232   template<>
 233     struct hash<thread::id>
 234     : public __hash_base<size_t, thread::id>
 235     {
 236       size_t
 237       operator()(const thread::id& __id) const noexcept
 238       { return std::_Hash_impl::hash(__id._M_thread); }
 239     };
 240
 241   template<class _CharT, class _Traits>
 242     inline basic_ostream<_CharT, _Traits>&
 243     operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
 244     {
 245       if (__id == thread::id())
 246         return __out << "thread::id of a non-executing thread";
 247       else
 248         return __out << __id._M_thread;
 249     }
 250
 251 _GLIBCXX_END_NAMESPACE_VERSION
 252
 253   /** @namespace std::this_thread
 254    *  @brief ISO C++ 2011 entities sub-namespace for thread.
 255    *  30.3.2 Namespace this_thread.
 256    */
 257   namespace this_thread
 258   {
 259   _GLIBCXX_BEGIN_NAMESPACE_VERSION
 260
 261     /// get_id
 262     inline thread::id
 263     get_id() noexcept { return thread::id(__gthread_self()); }
 264
 265     /// yield
 266     inline void
 267     yield() noexcept
 268     {
 269 #ifdef _GLIBCXX_USE_SCHED_YIELD
 270       __gthread_yield();
 271 #endif
 272     }
 273
 274     void
 275     __sleep_for(chrono::seconds, chrono::nanoseconds);
 276
 277     /// sleep_for
 278     template<typename _Rep, typename _Period>
 279       inline void
 280       sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
 281       {
 282         auto __s = chrono::duration_cast<chrono::seconds>(__rtime);
 283         auto __ns = chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
 284 #ifdef _GLIBCXX_USE_NANOSLEEP
 285         __gthread_time_t __ts =
 286           {
 287             static_cast<std::time_t>(__s.count()),
 288             static_cast<long>(__ns.count())
 289           };
 290         ::nanosleep(&__ts, 0);
 291 #else
 292         __sleep_for(__s, __ns);
 293 #endif
 294       }
 295
 296     /// sleep_until
 297     template<typename _Clock, typename _Duration>
 298       inline void
 299       sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
 300       { sleep_for(__atime - _Clock::now()); }
 301
 302   _GLIBCXX_END_NAMESPACE_VERSION
 303   }
 304
 305   // @} group threads
 306
 307 } // namespace
 308
 309 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
 310
 311 #endif // C++11
 312
 313 #endif // _GLIBCXX_THREAD