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      1 // <thread> -*- C++ -*-
      2 
      3 // Copyright (C) 2008, 2009, 2010, 2011 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 <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 namespace std _GLIBCXX_VISIBILITY(default)
     50 {
     51 _GLIBCXX_BEGIN_NAMESPACE_VERSION
     52 
     53   /**
     54    * @defgroup threads Threads
     55    * @ingroup concurrency
     56    *
     57    * Classes for thread support.
     58    * @{
     59    */
     60 
     61   /// thread
     62   class thread
     63   {
     64   public:
     65     typedef __gthread_t			native_handle_type;
     66     struct _Impl_base;
     67     typedef shared_ptr<_Impl_base>	__shared_base_type;
     68 
     69     /// thread::id
     70     class id
     71     {
     72       native_handle_type	_M_thread;
     73 
     74     public:
     75       id() : _M_thread() { }
     76 
     77       explicit
     78       id(native_handle_type __id) : _M_thread(__id) { }
     79 
     80     private:
     81       friend class thread;
     82       friend class hash<thread::id>;
     83 
     84       friend bool
     85       operator==(thread::id __x, thread::id __y)
     86       { return __gthread_equal(__x._M_thread, __y._M_thread); }
     87 
     88       friend bool
     89       operator<(thread::id __x, thread::id __y)
     90       { return __x._M_thread < __y._M_thread; }
     91 
     92       template<class _CharT, class _Traits>
     93 	friend basic_ostream<_CharT, _Traits>&
     94 	operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id);
     95     };
     96 
     97     // Simple base type that the templatized, derived class containing
     98     // an arbitrary functor can be converted to and called.
     99     struct _Impl_base
    100     {
    101       __shared_base_type	_M_this_ptr;
    102 
    103       inline virtual ~_Impl_base();
    104 
    105       virtual void _M_run() = 0;
    106     };
    107 
    108     template<typename _Callable>
    109       struct _Impl : public _Impl_base
    110       {
    111 	_Callable		_M_func;
    112 
    113 	_Impl(_Callable&& __f) : _M_func(std::forward<_Callable>(__f))
    114 	{ }
    115 
    116 	void
    117 	_M_run() { _M_func(); }
    118       };
    119 
    120   private:
    121     id				_M_id;
    122 
    123   public:
    124     thread() = default;
    125     thread(thread&) = delete;
    126     thread(const thread&) = delete;
    127 
    128     thread(thread&& __t)
    129     { swap(__t); }
    130 
    131     template<typename _Callable, typename... _Args>
    132       explicit 
    133       thread(_Callable&& __f, _Args&&... __args)
    134       {
    135         _M_start_thread(_M_make_routine(std::bind<void>(
    136                 std::forward<_Callable>(__f),
    137                 std::forward<_Args>(__args)...)));
    138       }
    139 
    140     ~thread()
    141     {
    142       if (joinable())
    143 	std::terminate();
    144     }
    145 
    146     thread& operator=(const thread&) = delete;
    147 
    148     thread& operator=(thread&& __t)
    149     {
    150       if (joinable())
    151 	std::terminate();
    152       swap(__t);
    153       return *this;
    154     }
    155 
    156     void
    157     swap(thread& __t)
    158     { std::swap(_M_id, __t._M_id); }
    159 
    160     bool
    161     joinable() const
    162     { return !(_M_id == id()); }
    163 
    164     void
    165     join();
    166 
    167     void
    168     detach();
    169 
    170     thread::id
    171     get_id() const
    172     { return _M_id; }
    173 
    174     /** @pre thread is joinable
    175      */
    176     native_handle_type
    177     native_handle()
    178     { return _M_id._M_thread; }
    179 
    180     // Returns a value that hints at the number of hardware thread contexts.
    181     static unsigned int
    182     hardware_concurrency()
    183     { return 0; }
    184 
    185   private:
    186     void
    187     _M_start_thread(__shared_base_type);
    188 
    189     template<typename _Callable>
    190       shared_ptr<_Impl<_Callable>>
    191       _M_make_routine(_Callable&& __f)
    192       {
    193 	// Create and allocate full data structure, not base.
    194 	return make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
    195       }
    196   };
    197 
    198   inline thread::_Impl_base::~_Impl_base() = default;
    199 
    200   inline void
    201   swap(thread& __x, thread& __y)
    202   { __x.swap(__y); }
    203 
    204   inline bool
    205   operator!=(thread::id __x, thread::id __y)
    206   { return !(__x == __y); }
    207 
    208   inline bool
    209   operator<=(thread::id __x, thread::id __y)
    210   { return !(__y < __x); }
    211 
    212   inline bool
    213   operator>(thread::id __x, thread::id __y)
    214   { return __y < __x; }
    215 
    216   inline bool
    217   operator>=(thread::id __x, thread::id __y)
    218   { return !(__x < __y); }
    219 
    220   // DR 889.
    221   /// std::hash specialization for thread::id.
    222   template<>
    223     struct hash<thread::id>
    224     : public __hash_base<size_t, thread::id>
    225     {
    226       size_t
    227       operator()(const thread::id& __id) const noexcept
    228       { return std::_Hash_impl::hash(__id._M_thread); }
    229     };
    230 
    231   template<class _CharT, class _Traits>
    232     inline basic_ostream<_CharT, _Traits>&
    233     operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
    234     {
    235       if (__id == thread::id())
    236 	return __out << "thread::id of a non-executing thread";
    237       else
    238 	return __out << __id._M_thread;
    239     }
    240 
    241 _GLIBCXX_END_NAMESPACE_VERSION
    242 
    243   /** @namespace std::this_thread
    244    *  @brief ISO C++ 0x entities sub namespace for thread.
    245    *  30.2.2 Namespace this_thread.
    246    */
    247   namespace this_thread
    248   {
    249   _GLIBCXX_BEGIN_NAMESPACE_VERSION
    250 
    251     /// get_id
    252     inline thread::id
    253     get_id() { return thread::id(__gthread_self()); }
    254 
    255 #ifdef _GLIBCXX_USE_SCHED_YIELD
    256     /// yield
    257     inline void
    258     yield()
    259     { __gthread_yield(); }
    260 #endif
    261 
    262 #ifdef _GLIBCXX_USE_NANOSLEEP
    263     /// sleep_until
    264     template<typename _Clock, typename _Duration>
    265       inline void
    266       sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
    267       { sleep_for(__atime - _Clock::now()); }
    268 
    269     /// sleep_for
    270     template<typename _Rep, typename _Period>
    271       inline void
    272       sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
    273       {
    274 	chrono::seconds __s =
    275 	  chrono::duration_cast<chrono::seconds>(__rtime);
    276 
    277 	chrono::nanoseconds __ns =
    278 	  chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
    279 
    280 	__gthread_time_t __ts =
    281 	  {
    282 	    static_cast<std::time_t>(__s.count()),
    283 	    static_cast<long>(__ns.count())
    284 	  };
    285 
    286 	::nanosleep(&__ts, 0);
    287       }
    288 #endif
    289 
    290   _GLIBCXX_END_NAMESPACE_VERSION
    291   }
    292 
    293   // @} group threads
    294 
    295 } // namespace
    296 
    297 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
    298 
    299 #endif // __GXX_EXPERIMENTAL_CXX0X__
    300 
    301 #endif // _GLIBCXX_THREAD
    302