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      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 	std::terminate();
    139     }
    140 
    141     thread& operator=(const thread&) = delete;
    142 
    143     thread& operator=(thread&& __t)
    144     {
    145       if (joinable())
    146 	std::terminate();
    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 void
    198   swap(thread&& __x, thread& __y)
    199   { __x.swap(__y); }
    200 
    201   inline void
    202   swap(thread& __x, thread&& __y)
    203   { __x.swap(__y); }
    204 
    205   inline bool
    206   operator!=(thread::id __x, thread::id __y)
    207   { return !(__x == __y); }
    208 
    209   inline bool
    210   operator<=(thread::id __x, thread::id __y)
    211   { return !(__y < __x); }
    212 
    213   inline bool
    214   operator>(thread::id __x, thread::id __y)
    215   { return __y < __x; }
    216 
    217   inline bool
    218   operator>=(thread::id __x, thread::id __y)
    219   { return !(__x < __y); }
    220 
    221   template<class _CharT, class _Traits>
    222     inline basic_ostream<_CharT, _Traits>&
    223     operator<<(basic_ostream<_CharT, _Traits>&& __out, thread::id __id)
    224     {
    225       if (__id == thread::id())
    226 	return __out << "thread::id of a non-executing thread";
    227       else
    228 	return __out << __id._M_thread;
    229     }
    230 
    231   /** @namespace std::this_thread
    232    *  @brief ISO C++ 0x entities sub namespace for thread.
    233    *  30.2.2 Namespace this_thread.
    234    */
    235   namespace this_thread
    236   {
    237     /// get_id
    238     inline thread::id
    239     get_id() { return thread::id(__gthread_self()); }
    240 
    241 #ifdef _GLIBCXX_USE_SCHED_YIELD
    242     /// yield
    243     inline void
    244     yield()
    245     { __gthread_yield(); }
    246 #endif
    247 
    248 #ifdef _GLIBCXX_USE_NANOSLEEP
    249     /// sleep_until
    250     template<typename _Clock, typename _Duration>
    251       inline void
    252       sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
    253       { sleep_for(__atime - _Clock::now()); }
    254 
    255     /// sleep_for
    256     template<typename _Rep, typename _Period>
    257       inline void
    258       sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
    259       {
    260 	chrono::seconds __s =
    261 	  chrono::duration_cast<chrono::seconds>(__rtime);
    262 
    263 	chrono::nanoseconds __ns =
    264 	  chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
    265 
    266 	__gthread_time_t __ts =
    267 	  {
    268 	    static_cast<std::time_t>(__s.count()),
    269 	    static_cast<long>(__ns.count())
    270 	  };
    271 
    272 	::nanosleep(&__ts, 0);
    273       }
    274 #endif
    275   }
    276 
    277   // @} group threads
    278 }
    279 
    280 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
    281 
    282 #endif // __GXX_EXPERIMENTAL_CXX0X__
    283 
    284 #endif // _GLIBCXX_THREAD
    285