libstdc++-v3/include/std/thread

   1 // <thread> -*- C++ -*-
   2
   3 // Copyright (C) 2008, 2009, 2010, 2011, 2012 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 <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     thread(thread&) = delete;
 124     thread(const thread&) = delete;
 125
 126     thread(thread&& __t) noexcept
 127     { swap(__t); }
 128
 129     template<typename _Callable, typename... _Args>
 130       explicit
 131       thread(_Callable&& __f, _Args&&... __args)
 132       {
 133         _M_start_thread(_M_make_routine(std::__bind_simple(
 134                 std::forward<_Callable>(__f),
 135                 std::forward<_Args>(__args)...)));
 136       }
 137
 138     ~thread()
 139     {
 140       if (joinable())
 141         std::terminate();
 142     }
 143
 144     thread& operator=(const thread&) = delete;
 145
 146     thread& operator=(thread&& __t) noexcept
 147     {
 148       if (joinable())
 149         std::terminate();
 150       swap(__t);
 151       return *this;
 152     }
 153
 154     void
 155     swap(thread& __t) noexcept
 156     { std::swap(_M_id, __t._M_id); }
 157
 158     bool
 159     joinable() const noexcept
 160     { return !(_M_id == id()); }
 161
 162     void
 163     join();
 164
 165     void
 166     detach();
 167
 168     thread::id
 169     get_id() const noexcept
 170     { return _M_id; }
 171
 172     /** @pre thread is joinable
 173      */
 174     native_handle_type
 175     native_handle()
 176     { return _M_id._M_thread; }
 177
 178     // Returns a value that hints at the number of hardware thread contexts.
 179     static unsigned int
 180     hardware_concurrency() noexcept;
 181
 182   private:
 183     void
 184     _M_start_thread(__shared_base_type);
 185
 186     template<typename _Callable>
 187       shared_ptr<_Impl<_Callable>>
 188       _M_make_routine(_Callable&& __f)
 189       {
 190         // Create and allocate full data structure, not base.
 191         return std::make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
 192       }
 193   };
 194
 195   inline thread::_Impl_base::~_Impl_base() = default;
 196
 197   inline void
 198   swap(thread& __x, thread& __y) noexcept
 199   { __x.swap(__y); }
 200
 201   inline bool
 202   operator!=(thread::id __x, thread::id __y) noexcept
 203   { return !(__x == __y); }
 204
 205   inline bool
 206   operator<=(thread::id __x, thread::id __y) noexcept
 207   { return !(__y < __x); }
 208
 209   inline bool
 210   operator>(thread::id __x, thread::id __y) noexcept
 211   { return __y < __x; }
 212
 213   inline bool
 214   operator>=(thread::id __x, thread::id __y) noexcept
 215   { return !(__x < __y); }
 216
 217   // DR 889.
 218   /// std::hash specialization for thread::id.
 219   template<>
 220     struct hash<thread::id>
 221     : public __hash_base<size_t, thread::id>
 222     {
 223       size_t
 224       operator()(const thread::id& __id) const noexcept
 225       { return std::_Hash_impl::hash(__id._M_thread); }
 226     };
 227
 228   template<class _CharT, class _Traits>
 229     inline basic_ostream<_CharT, _Traits>&
 230     operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
 231     {
 232       if (__id == thread::id())
 233         return __out << "thread::id of a non-executing thread";
 234       else
 235         return __out << __id._M_thread;
 236     }
 237
 238 _GLIBCXX_END_NAMESPACE_VERSION
 239
 240   /** @namespace std::this_thread
 241    *  @brief ISO C++ 0x entities sub namespace for thread.
 242    *  30.2.2 Namespace this_thread.
 243    */
 244   namespace this_thread
 245   {
 246   _GLIBCXX_BEGIN_NAMESPACE_VERSION
 247
 248     /// get_id
 249     inline thread::id
 250     get_id() noexcept { return thread::id(__gthread_self()); }
 251
 252 #ifdef _GLIBCXX_USE_SCHED_YIELD
 253     /// yield
 254     inline void
 255     yield() noexcept
 256     { __gthread_yield(); }
 257 #endif
 258
 259 #ifdef _GLIBCXX_USE_NANOSLEEP
 260     /// sleep_for
 261     template<typename _Rep, typename _Period>
 262       inline void
 263       sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
 264       {
 265         chrono::seconds __s =
 266           chrono::duration_cast<chrono::seconds>(__rtime);
 267
 268         chrono::nanoseconds __ns =
 269           chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
 270
 271         __gthread_time_t __ts =
 272           {
 273             static_cast<std::time_t>(__s.count()),
 274             static_cast<long>(__ns.count())
 275           };
 276
 277         ::nanosleep(&__ts, 0);
 278       }
 279
 280     /// sleep_until
 281     template<typename _Clock, typename _Duration>
 282       inline void
 283       sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
 284       { sleep_for(__atime - _Clock::now()); }
 285 #endif
 286
 287   _GLIBCXX_END_NAMESPACE_VERSION
 288   }
 289
 290   // @} group threads
 291
 292 } // namespace
 293
 294 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
 295
 296 #endif // __GXX_EXPERIMENTAL_CXX0X__
 297
 298 #endif // _GLIBCXX_THREAD