thread

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00001 // <thread> -*- C++ -*-
00002 
00003 // Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 3, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /** @file thread
00026  *  This is a Standard C++ Library header.
00027  */
00028 
00029 #ifndef _GLIBCXX_THREAD
00030 #define _GLIBCXX_THREAD 1
00031 
00032 #pragma GCC system_header
00033 
00034 #ifndef __GXX_EXPERIMENTAL_CXX0X__
00035 # include <bits/c++0x_warning.h>
00036 #else
00037 
00038 #include <chrono>
00039 #include <functional>
00040 #include <memory>
00041 #include <mutex>
00042 #include <condition_variable>
00043 #include <cstddef>
00044 #include <bits/functexcept.h>
00045 #include <bits/functional_hash.h>
00046 #include <bits/gthr.h>
00047 
00048 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
00049 
00050 namespace std
00051 {
00052   /**
00053    * @defgroup threads Threads
00054    * @ingroup concurrency
00055    *
00056    * Classes for thread support.
00057    * @{
00058    */
00059 
00060   template<typename _Tp>
00061     struct hash;
00062 
00063   /// thread
00064   class thread
00065   {
00066   public:
00067     typedef __gthread_t         native_handle_type;
00068     struct _Impl_base;
00069     typedef shared_ptr<_Impl_base>  __shared_base_type;
00070 
00071     /// thread::id
00072     class id
00073     {
00074       native_handle_type    _M_thread;
00075 
00076     public:
00077       id() : _M_thread() { }
00078 
00079       explicit
00080       id(native_handle_type __id) : _M_thread(__id) { }
00081 
00082     private:
00083       friend class thread;
00084       friend class hash<thread::id>;
00085 
00086       friend bool
00087       operator==(thread::id __x, thread::id __y)
00088       { return __gthread_equal(__x._M_thread, __y._M_thread); }
00089 
00090       friend bool
00091       operator<(thread::id __x, thread::id __y)
00092       { return __x._M_thread < __y._M_thread; }
00093 
00094       template<class _CharT, class _Traits>
00095     friend basic_ostream<_CharT, _Traits>&
00096     operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id);
00097     };
00098 
00099     // Simple base type that the templatized, derived class containing
00100     // an arbitrary functor can be converted to and called.
00101     struct _Impl_base
00102     {
00103       __shared_base_type    _M_this_ptr;
00104 
00105       inline virtual ~_Impl_base();
00106 
00107       virtual void _M_run() = 0;
00108     };
00109 
00110     template<typename _Callable>
00111       struct _Impl : public _Impl_base
00112       {
00113     _Callable       _M_func;
00114 
00115     _Impl(_Callable&& __f) : _M_func(std::forward<_Callable>(__f))
00116     { }
00117 
00118     void
00119     _M_run() { _M_func(); }
00120       };
00121 
00122   private:
00123     id              _M_id;
00124 
00125   public:
00126     thread() = default;
00127     thread(const thread&) = delete;
00128 
00129     thread(thread&& __t)
00130     { swap(__t); }
00131 
00132     template<typename _Callable>
00133       explicit thread(_Callable __f)
00134       {
00135     _M_start_thread(_M_make_routine<_Callable>
00136             (std::forward<_Callable>(__f)));
00137       }
00138 
00139     template<typename _Callable, typename... _Args>
00140       thread(_Callable&& __f, _Args&&... __args)
00141       { _M_start_thread(_M_make_routine(std::bind(__f, __args...))); }
00142 
00143     ~thread()
00144     {
00145       if (joinable())
00146     std::terminate();
00147     }
00148 
00149     thread& operator=(const thread&) = delete;
00150 
00151     thread& operator=(thread&& __t)
00152     {
00153       if (joinable())
00154     std::terminate();
00155       swap(__t);
00156       return *this;
00157     }
00158 
00159     void
00160     swap(thread& __t)
00161     { std::swap(_M_id, __t._M_id); }
00162 
00163     bool
00164     joinable() const
00165     { return !(_M_id == id()); }
00166 
00167     void
00168     join();
00169 
00170     void
00171     detach();
00172 
00173     thread::id
00174     get_id() const
00175     { return _M_id; }
00176 
00177     /** @pre thread is joinable
00178      */
00179     native_handle_type
00180     native_handle()
00181     { return _M_id._M_thread; }
00182 
00183     // Returns a value that hints at the number of hardware thread contexts.
00184     static unsigned int
00185     hardware_concurrency()
00186     { return 0; }
00187 
00188   private:
00189     void
00190     _M_start_thread(__shared_base_type);
00191 
00192     template<typename _Callable>
00193       shared_ptr<_Impl<_Callable>>
00194       _M_make_routine(_Callable&& __f)
00195       {
00196     // Create and allocate full data structure, not base.
00197     return make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
00198       }
00199   };
00200 
00201   inline thread::_Impl_base::~_Impl_base() = default;
00202 
00203   inline void
00204   swap(thread& __x, thread& __y)
00205   { __x.swap(__y); }
00206 
00207   inline bool
00208   operator!=(thread::id __x, thread::id __y)
00209   { return !(__x == __y); }
00210 
00211   inline bool
00212   operator<=(thread::id __x, thread::id __y)
00213   { return !(__y < __x); }
00214 
00215   inline bool
00216   operator>(thread::id __x, thread::id __y)
00217   { return __y < __x; }
00218 
00219   inline bool
00220   operator>=(thread::id __x, thread::id __y)
00221   { return !(__x < __y); }
00222 
00223   // DR 889.
00224   /// std::hash specialization for thread::id.
00225   template<>
00226     struct hash<thread::id>
00227     : public std::unary_function<thread::id, size_t>
00228     {
00229       size_t
00230       operator()(const thread::id& __id) const
00231       { return std::_Fnv_hash::hash(__id._M_thread); }
00232     };
00233 
00234   template<class _CharT, class _Traits>
00235     inline basic_ostream<_CharT, _Traits>&
00236     operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
00237     {
00238       if (__id == thread::id())
00239     return __out << "thread::id of a non-executing thread";
00240       else
00241     return __out << __id._M_thread;
00242     }
00243 
00244   /** @namespace std::this_thread
00245    *  @brief ISO C++ 0x entities sub namespace for thread.
00246    *  30.2.2 Namespace this_thread.
00247    */
00248   namespace this_thread
00249   {
00250     /// get_id
00251     inline thread::id
00252     get_id() { return thread::id(__gthread_self()); }
00253 
00254 #ifdef _GLIBCXX_USE_SCHED_YIELD
00255     /// yield
00256     inline void
00257     yield()
00258     { __gthread_yield(); }
00259 #endif
00260 
00261 #ifdef _GLIBCXX_USE_NANOSLEEP
00262     /// sleep_until
00263     template<typename _Clock, typename _Duration>
00264       inline void
00265       sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
00266       { sleep_for(__atime - _Clock::now()); }
00267 
00268     /// sleep_for
00269     template<typename _Rep, typename _Period>
00270       inline void
00271       sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
00272       {
00273     chrono::seconds __s =
00274       chrono::duration_cast<chrono::seconds>(__rtime);
00275 
00276     chrono::nanoseconds __ns =
00277       chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
00278 
00279     __gthread_time_t __ts =
00280       {
00281         static_cast<std::time_t>(__s.count()),
00282         static_cast<long>(__ns.count())
00283       };
00284 
00285     ::nanosleep(&__ts, 0);
00286       }
00287 #endif
00288   }
00289 
00290   // @} group threads
00291 }
00292 
00293 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
00294 
00295 #endif // __GXX_EXPERIMENTAL_CXX0X__
00296 
00297 #endif // _GLIBCXX_THREAD