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