libstdc++-v3/include/std/thread

   1 // <thread> -*- C++ -*-
   2
   3 // Copyright (C) 2008, 2009, 2010, 2011 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 #ifndef __GXX_EXPERIMENTAL_CXX0X__
  35 # include <bits/c++0x_warning.h>
  36 #else
  37
  38 #include <chrono>
  39 #include <functional>
  40 #include <memory>
  41 #include <mutex>
  42 #include <condition_variable>
  43 #include <bits/functexcept.h>
  44 #include <bits/functional_hash.h>
  45 #include <bits/gthr.h>
  46
  47 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
  48
  49 namespace std _GLIBCXX_VISIBILITY(default)
  50 {
  51 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  52
  53   /**
  54    * @defgroup threads Threads
  55    * @ingroup concurrency
  56    *
  57    * Classes for thread support.
  58    * @{
  59    */
  60
  61   /// thread
  62   class thread
  63   {
  64   public:
  65     typedef __gthread_t                 native_handle_type;
  66     struct _Impl_base;
  67     typedef shared_ptr<_Impl_base>      __shared_base_type;
  68
  69     /// thread::id
  70     class id
  71     {
  72       native_handle_type        _M_thread;
  73
  74     public:
  75       id() : _M_thread() { }
  76
  77       explicit
  78       id(native_handle_type __id) : _M_thread(__id) { }
  79
  80     private:
  81       friend class thread;
  82       friend class hash<thread::id>;
  83
  84       friend bool
  85       operator==(thread::id __x, thread::id __y)
  86       { return __gthread_equal(__x._M_thread, __y._M_thread); }
  87
  88       friend bool
  89       operator<(thread::id __x, thread::id __y)
  90       { return __x._M_thread < __y._M_thread; }
  91
  92       template<class _CharT, class _Traits>
  93         friend basic_ostream<_CharT, _Traits>&
  94         operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id);
  95     };
  96
  97     // Simple base type that the templatized, derived class containing
  98     // an arbitrary functor can be converted to and called.
  99     struct _Impl_base
 100     {
 101       __shared_base_type        _M_this_ptr;
 102
 103       virtual ~_Impl_base();
 104
 105       virtual void _M_run() = 0;
 106     };
 107
 108     template<typename _Callable>
 109       struct _Impl : public _Impl_base
 110       {
 111         _Callable               _M_func;
 112
 113         _Impl(_Callable&& __f) : _M_func(std::forward<_Callable>(__f))
 114         { }
 115
 116         void
 117         _M_run() { _M_func(); }
 118       };
 119
 120   private:
 121     id                          _M_id;
 122
 123   public:
 124     thread() = default;
 125     thread(thread&) = delete;
 126     thread(const thread&) = delete;
 127
 128     thread(thread&& __t)
 129     { swap(__t); }
 130
 131     template<typename _Callable, typename... _Args>
 132       explicit
 133       thread(_Callable&& __f, _Args&&... __args)
 134       {
 135         _M_start_thread(_M_make_routine(std::bind<void>(
 136                 std::forward<_Callable>(__f),
 137                 std::forward<_Args>(__args)...)));
 138       }
 139
 140     ~thread()
 141     {
 142       if (joinable())
 143         std::terminate();
 144     }
 145
 146     thread& operator=(const thread&) = delete;
 147
 148     thread& operator=(thread&& __t)
 149     {
 150       if (joinable())
 151         std::terminate();
 152       swap(__t);
 153       return *this;
 154     }
 155
 156     void
 157     swap(thread& __t)
 158     { std::swap(_M_id, __t._M_id); }
 159
 160     bool
 161     joinable() const
 162     { return !(_M_id == id()); }
 163
 164     void
 165     join();
 166
 167     void
 168     detach();
 169
 170     thread::id
 171     get_id() const
 172     { return _M_id; }
 173
 174     /** @pre thread is joinable
 175      */
 176     native_handle_type
 177     native_handle()
 178     { return _M_id._M_thread; }
 179
 180     // Returns a value that hints at the number of hardware thread contexts.
 181     static unsigned int
 182     hardware_concurrency()
 183     { return 0; }
 184
 185   private:
 186     void
 187     _M_start_thread(__shared_base_type);
 188
 189     template<typename _Callable>
 190       shared_ptr<_Impl<_Callable>>
 191       _M_make_routine(_Callable&& __f)
 192       {
 193         // Create and allocate full data structure, not base.
 194         return make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
 195       }
 196   };
 197
 198   inline void
 199   swap(thread& __x, thread& __y)
 200   { __x.swap(__y); }
 201
 202   inline bool
 203   operator!=(thread::id __x, thread::id __y)
 204   { return !(__x == __y); }
 205
 206   inline bool
 207   operator<=(thread::id __x, thread::id __y)
 208   { return !(__y < __x); }
 209
 210   inline bool
 211   operator>(thread::id __x, thread::id __y)
 212   { return __y < __x; }
 213
 214   inline bool
 215   operator>=(thread::id __x, thread::id __y)
 216   { return !(__x < __y); }
 217
 218   // DR 889.
 219   /// std::hash specialization for thread::id.
 220   template<>
 221     struct hash<thread::id>
 222     : public __hash_base<size_t, thread::id>
 223     {
 224       size_t
 225       operator()(const thread::id& __id) const
 226       { return std::_Hash_impl::hash(__id._M_thread); }
 227     };
 228
 229   template<class _CharT, class _Traits>
 230     inline basic_ostream<_CharT, _Traits>&
 231     operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
 232     {
 233       if (__id == thread::id())
 234         return __out << "thread::id of a non-executing thread";
 235       else
 236         return __out << __id._M_thread;
 237     }
 238
 239 _GLIBCXX_END_NAMESPACE_VERSION
 240
 241   /** @namespace std::this_thread
 242    *  @brief ISO C++ 0x entities sub namespace for thread.
 243    *  30.2.2 Namespace this_thread.
 244    */
 245   namespace this_thread
 246   {
 247   _GLIBCXX_BEGIN_NAMESPACE_VERSION
 248
 249     /// get_id
 250     inline thread::id
 251     get_id() { return thread::id(__gthread_self()); }
 252
 253 #ifdef _GLIBCXX_USE_SCHED_YIELD
 254     /// yield
 255     inline void
 256     yield()
 257     { __gthread_yield(); }
 258 #endif
 259
 260 #ifdef _GLIBCXX_USE_NANOSLEEP
 261     /// sleep_until
 262     template<typename _Clock, typename _Duration>
 263       inline void
 264       sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
 265       { sleep_for(__atime - _Clock::now()); }
 266
 267     /// sleep_for
 268     template<typename _Rep, typename _Period>
 269       inline void
 270       sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
 271       {
 272         chrono::seconds __s =
 273           chrono::duration_cast<chrono::seconds>(__rtime);
 274
 275         chrono::nanoseconds __ns =
 276           chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
 277
 278         __gthread_time_t __ts =
 279           {
 280             static_cast<std::time_t>(__s.count()),
 281             static_cast<long>(__ns.count())
 282           };
 283
 284         ::nanosleep(&__ts, 0);
 285       }
 286 #endif
 287
 288   _GLIBCXX_END_NAMESPACE_VERSION
 289   }
 290
 291   // @} group threads
 292
 293 } // namespace
 294
 295 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
 296
 297 #endif // __GXX_EXPERIMENTAL_CXX0X__
 298
 299 #endif // _GLIBCXX_THREAD