libstdc++-v3/include/std/thread

   1 // <thread> -*- C++ -*-
   2
   3 // Copyright (C) 2008, 2009, 2010 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 <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 _GLIBCXX_BEGIN_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       friend class hash<thread::id>;
  81
  82       friend bool
  83       operator==(thread::id __x, thread::id __y)
  84       { return __gthread_equal(__x._M_thread, __y._M_thread); }
  85
  86       friend bool
  87       operator<(thread::id __x, thread::id __y)
  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() = default;
 123     thread(thread&) = delete;
 124     thread(const thread&) = delete;
 125
 126     thread(thread&& __t)
 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<void>(
 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)
 147     {
 148       if (joinable())
 149         std::terminate();
 150       swap(__t);
 151       return *this;
 152     }
 153
 154     void
 155     swap(thread& __t)
 156     { std::swap(_M_id, __t._M_id); }
 157
 158     bool
 159     joinable() const
 160     { return !(_M_id == id()); }
 161
 162     void
 163     join();
 164
 165     void
 166     detach();
 167
 168     thread::id
 169     get_id() const
 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()
 181     { return 0; }
 182
 183   private:
 184     void
 185     _M_start_thread(__shared_base_type);
 186
 187     template<typename _Callable>
 188       shared_ptr<_Impl<_Callable>>
 189       _M_make_routine(_Callable&& __f)
 190       {
 191         // Create and allocate full data structure, not base.
 192         return make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
 193       }
 194   };
 195
 196   inline thread::_Impl_base::~_Impl_base() = default;
 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   /** @namespace std::this_thread
 240    *  @brief ISO C++ 0x entities sub namespace for thread.
 241    *  30.2.2 Namespace this_thread.
 242    */
 243   namespace this_thread
 244   {
 245     /// get_id
 246     inline thread::id
 247     get_id() { return thread::id(__gthread_self()); }
 248
 249 #ifdef _GLIBCXX_USE_SCHED_YIELD
 250     /// yield
 251     inline void
 252     yield()
 253     { __gthread_yield(); }
 254 #endif
 255
 256 #ifdef _GLIBCXX_USE_NANOSLEEP
 257     /// sleep_until
 258     template<typename _Clock, typename _Duration>
 259       inline void
 260       sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
 261       { sleep_for(__atime - _Clock::now()); }
 262
 263     /// sleep_for
 264     template<typename _Rep, typename _Period>
 265       inline void
 266       sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
 267       {
 268         chrono::seconds __s =
 269           chrono::duration_cast<chrono::seconds>(__rtime);
 270
 271         chrono::nanoseconds __ns =
 272           chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
 273
 274         __gthread_time_t __ts =
 275           {
 276             static_cast<std::time_t>(__s.count()),
 277             static_cast<long>(__ns.count())
 278           };
 279
 280         ::nanosleep(&__ts, 0);
 281       }
 282 #endif
 283   }
 284
 285   // @} group threads
 286 _GLIBCXX_END_NAMESPACE
 287
 288 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
 289
 290 #endif // __GXX_EXPERIMENTAL_CXX0X__
 291
 292 #endif // _GLIBCXX_THREAD