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 <bits/functexcept.h>
00044 #include <bits/functional_hash.h>
00045 #include <bits/gthr.h>
00046 
00047 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
00048 
00049 namespace std
00050 {
00051   /**
00052    * @defgroup threads Threads
00053    * @ingroup concurrency
00054    *
00055    * Classes for thread support.
00056    * @{
00057    */
00058 
00059   /// thread
00060   class thread
00061   {
00062   public:
00063     typedef __gthread_t         native_handle_type;
00064     struct _Impl_base;
00065     typedef shared_ptr<_Impl_base>  __shared_base_type;
00066 
00067     /// thread::id
00068     class id
00069     {
00070       native_handle_type    _M_thread;
00071 
00072     public:
00073       id() : _M_thread() { }
00074 
00075       explicit
00076       id(native_handle_type __id) : _M_thread(__id) { }
00077 
00078     private:
00079       friend class thread;
00080       friend class hash<thread::id>;
00081 
00082       friend bool
00083       operator==(thread::id __x, thread::id __y)
00084       { return __gthread_equal(__x._M_thread, __y._M_thread); }
00085 
00086       friend bool
00087       operator<(thread::id __x, thread::id __y)
00088       { return __x._M_thread < __y._M_thread; }
00089 
00090       template<class _CharT, class _Traits>
00091     friend basic_ostream<_CharT, _Traits>&
00092     operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id);
00093     };
00094 
00095     // Simple base type that the templatized, derived class containing
00096     // an arbitrary functor can be converted to and called.
00097     struct _Impl_base
00098     {
00099       __shared_base_type    _M_this_ptr;
00100 
00101       inline virtual ~_Impl_base();
00102 
00103       virtual void _M_run() = 0;
00104     };
00105 
00106     template<typename _Callable>
00107       struct _Impl : public _Impl_base
00108       {
00109     _Callable       _M_func;
00110 
00111     _Impl(_Callable&& __f) : _M_func(std::forward<_Callable>(__f))
00112     { }
00113 
00114     void
00115     _M_run() { _M_func(); }
00116       };
00117 
00118   private:
00119     id              _M_id;
00120 
00121   public:
00122     thread() = default;
00123     thread(thread&) = delete;
00124     thread(const thread&) = delete;
00125 
00126     thread(thread&& __t)
00127     { swap(__t); }
00128 
00129     template<typename _Callable, typename... _Args>
00130       explicit 
00131       thread(_Callable&& __f, _Args&&... __args)
00132       {
00133         _M_start_thread(_M_make_routine(std::bind<void>(
00134                 std::forward<_Callable>(__f),
00135                 std::forward<_Args>(__args)...)));
00136       }
00137 
00138     ~thread()
00139     {
00140       if (joinable())
00141     std::terminate();
00142     }
00143 
00144     thread& operator=(const thread&) = delete;
00145 
00146     thread& operator=(thread&& __t)
00147     {
00148       if (joinable())
00149     std::terminate();
00150       swap(__t);
00151       return *this;
00152     }
00153 
00154     void
00155     swap(thread& __t)
00156     { std::swap(_M_id, __t._M_id); }
00157 
00158     bool
00159     joinable() const
00160     { return !(_M_id == id()); }
00161 
00162     void
00163     join();
00164 
00165     void
00166     detach();
00167 
00168     thread::id
00169     get_id() const
00170     { return _M_id; }
00171 
00172     /** @pre thread is joinable
00173      */
00174     native_handle_type
00175     native_handle()
00176     { return _M_id._M_thread; }
00177 
00178     // Returns a value that hints at the number of hardware thread contexts.
00179     static unsigned int
00180     hardware_concurrency()
00181     { return 0; }
00182 
00183   private:
00184     void
00185     _M_start_thread(__shared_base_type);
00186 
00187     template<typename _Callable>
00188       shared_ptr<_Impl<_Callable>>
00189       _M_make_routine(_Callable&& __f)
00190       {
00191     // Create and allocate full data structure, not base.
00192     return make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
00193       }
00194   };
00195 
00196   inline thread::_Impl_base::~_Impl_base() = default;
00197 
00198   inline void
00199   swap(thread& __x, thread& __y)
00200   { __x.swap(__y); }
00201 
00202   inline bool
00203   operator!=(thread::id __x, thread::id __y)
00204   { return !(__x == __y); }
00205 
00206   inline bool
00207   operator<=(thread::id __x, thread::id __y)
00208   { return !(__y < __x); }
00209 
00210   inline bool
00211   operator>(thread::id __x, thread::id __y)
00212   { return __y < __x; }
00213 
00214   inline bool
00215   operator>=(thread::id __x, thread::id __y)
00216   { return !(__x < __y); }
00217 
00218   // DR 889.
00219   /// std::hash specialization for thread::id.
00220   template<>
00221     struct hash<thread::id>
00222     : public __hash_base<size_t, thread::id>
00223     {
00224       size_t
00225       operator()(const thread::id& __id) const
00226       { return std::_Hash_impl::hash(__id._M_thread); }
00227     };
00228 
00229   template<class _CharT, class _Traits>
00230     inline basic_ostream<_CharT, _Traits>&
00231     operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
00232     {
00233       if (__id == thread::id())
00234     return __out << "thread::id of a non-executing thread";
00235       else
00236     return __out << __id._M_thread;
00237     }
00238 
00239   /** @namespace std::this_thread
00240    *  @brief ISO C++ 0x entities sub namespace for thread.
00241    *  30.2.2 Namespace this_thread.
00242    */
00243   namespace this_thread
00244   {
00245     /// get_id
00246     inline thread::id
00247     get_id() { return thread::id(__gthread_self()); }
00248 
00249 #ifdef _GLIBCXX_USE_SCHED_YIELD
00250     /// yield
00251     inline void
00252     yield()
00253     { __gthread_yield(); }
00254 #endif
00255 
00256 #ifdef _GLIBCXX_USE_NANOSLEEP
00257     /// sleep_until
00258     template<typename _Clock, typename _Duration>
00259       inline void
00260       sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
00261       { sleep_for(__atime - _Clock::now()); }
00262 
00263     /// sleep_for
00264     template<typename _Rep, typename _Period>
00265       inline void
00266       sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
00267       {
00268     chrono::seconds __s =
00269       chrono::duration_cast<chrono::seconds>(__rtime);
00270 
00271     chrono::nanoseconds __ns =
00272       chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
00273 
00274     __gthread_time_t __ts =
00275       {
00276         static_cast<std::time_t>(__s.count()),
00277         static_cast<long>(__ns.count())
00278       };
00279 
00280     ::nanosleep(&__ts, 0);
00281       }
00282 #endif
00283   }
00284 
00285   // @} group threads
00286 }
00287 
00288 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
00289 
00290 #endif // __GXX_EXPERIMENTAL_CXX0X__
00291 
00292 #endif // _GLIBCXX_THREAD