libstdc++-v3/include/std/thread

   1 // <thread> -*- C++ -*-
   2
   3 // Copyright (C) 2008, 2009 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 2, 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 // You should have received a copy of the GNU General Public License
  17 // along with this library; see the file COPYING.  If not, write to
  18 // the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  19 // Boston, MA 02110-1301, USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 /** @file thread
  31  *  This is a Standard C++ Library header.
  32  */
  33
  34 #ifndef _GLIBCXX_THREAD
  35 #define _GLIBCXX_THREAD 1
  36
  37 #pragma GCC system_header
  38
  39 #ifndef __GXX_EXPERIMENTAL_CXX0X__
  40 # include <c++0x_warning.h>
  41 #else
  42
  43 #include <chrono>
  44 #include <functional>
  45 #include <memory>
  46 #include <mutex>
  47 #include <condition_variable>
  48 #include <cstddef>
  49 #include <bits/functexcept.h>
  50 #include <bits/gthr.h>
  51
  52 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
  53
  54 namespace std
  55 {
  56   /// thread
  57   class thread
  58   {
  59   public:
  60     typedef __gthread_t                 native_handle_type;
  61     struct _Impl_base;
  62     typedef shared_ptr<_Impl_base>      __shared_base_type;
  63
  64     /// thread::id
  65     class id
  66     {
  67       native_handle_type        _M_thread;
  68
  69     public:
  70       id() : _M_thread() { }
  71
  72       explicit
  73       id(native_handle_type __id) : _M_thread(__id) { }
  74
  75     private:
  76       friend class thread;
  77
  78       friend bool
  79       operator==(thread::id __x, thread::id __y)
  80       { return __gthread_equal(__x._M_thread, __y._M_thread); }
  81
  82       friend bool
  83       operator<(thread::id __x, thread::id __y)
  84       { return __x._M_thread < __y._M_thread; }
  85
  86       template<class _CharT, class _Traits>
  87         friend basic_ostream<_CharT, _Traits>&
  88         operator<<(basic_ostream<_CharT, _Traits>&& __out, thread::id __id);
  89     };
  90
  91     // Simple base type that the templatized, derived class containing
  92     // an abitrary functor can be converted to and called.
  93     struct _Impl_base
  94     {
  95       __shared_base_type        _M_this_ptr;
  96
  97       virtual ~_Impl_base() = default;
  98
  99       virtual void _M_run() = 0;
 100     };
 101
 102     template<typename _Callable>
 103       struct _Impl : public _Impl_base
 104       {
 105         _Callable               _M_func;
 106
 107         _Impl(_Callable&& __f) : _M_func(std::forward<_Callable>(__f))
 108         { }
 109
 110         void
 111         _M_run() { _M_func(); }
 112       };
 113
 114   private:
 115     id                          _M_id;
 116
 117   public:
 118     thread() = default;
 119     thread(const thread&) = delete;
 120
 121     thread(thread&& __t)
 122     { swap(__t); }
 123
 124     template<typename _Callable>
 125       explicit thread(_Callable __f)
 126       { _M_start_thread(_M_make_routine<_Callable>(__f)); }
 127
 128     template<typename _Callable, typename... _Args>
 129       thread(_Callable&& __f, _Args&&... __args)
 130       { _M_start_thread(_M_make_routine(std::bind(__f, __args...))); }
 131
 132     ~thread()
 133     {
 134       if (joinable())
 135         detach();
 136     }
 137
 138     thread& operator=(const thread&) = delete;
 139
 140     thread& operator=(thread&& __t)
 141     {
 142       if (joinable())
 143         detach();
 144       swap(__t);
 145       return *this;
 146     }
 147
 148     void
 149     swap(thread&& __t)
 150     { std::swap(_M_id, __t._M_id); }
 151
 152     bool
 153     joinable() const
 154     { return !(_M_id == id()); }
 155
 156     void
 157     join();
 158
 159     void
 160     detach();
 161
 162     thread::id
 163     get_id() const
 164     { return _M_id; }
 165
 166     /** @pre thread is joinable
 167      */
 168     native_handle_type
 169     native_handle()
 170     { return _M_id._M_thread; }
 171
 172     // Returns a value that hints at the number of hardware thread contexts.
 173     static unsigned int
 174     hardware_concurrency()
 175     { return 0; }
 176
 177   private:
 178     void
 179     _M_start_thread(__shared_base_type);
 180
 181     template<typename _Callable>
 182       shared_ptr<_Impl<_Callable>>
 183       _M_make_routine(_Callable&& __f)
 184       {
 185         // Create and allocate full data structure, not base.
 186         return make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
 187       }
 188   };
 189
 190   inline void
 191   swap(thread& __x, thread& __y)
 192   { __x.swap(__y); }
 193
 194   inline void
 195   swap(thread&& __x, thread& __y)
 196   { __x.swap(__y); }
 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   template<class _CharT, class _Traits>
 219     inline basic_ostream<_CharT, _Traits>&
 220     operator<<(basic_ostream<_CharT, _Traits>&& __out, thread::id __id)
 221     {
 222       if (__id == thread::id())
 223         return __out << "thread::id of a non-executing thread";
 224       else
 225         return __out << __id._M_thread;
 226     }
 227
 228   // 30.2.2 Namespace this_thread.
 229   namespace this_thread
 230   {
 231     /// get_id
 232     inline thread::id
 233     get_id() { return thread::id(__gthread_self()); }
 234
 235 #ifdef _GLIBCXX_USE_SCHED_YIELD
 236     /// yield
 237     inline void
 238     yield()
 239     { __gthread_yield(); }
 240 #endif
 241
 242 #ifdef _GLIBCXX_USE_NANOSLEEP
 243     /// sleep_until
 244     template<typename _Clock, typename _Duration>
 245       inline void
 246       sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
 247       { sleep_for(__atime - _Clock::now()); }
 248
 249     /// sleep_for
 250     template<typename _Rep, typename _Period>
 251       inline void
 252       sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
 253       {
 254         chrono::seconds __s =
 255           chrono::duration_cast<chrono::seconds>(__rtime);
 256
 257         chrono::nanoseconds __ns =
 258           chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
 259
 260         __gthread_time_t __ts =
 261           {
 262             static_cast<std::time_t>(__s.count()),
 263             static_cast<long>(__ns.count())
 264           };
 265
 266         ::nanosleep(&__ts, 0);
 267       }
 268 #endif
 269   }
 270 }
 271
 272 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
 273
 274 #endif // __GXX_EXPERIMENTAL_CXX0X__
 275
 276 #endif // _GLIBCXX_THREAD