thread

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00001 // <thread> -*- C++ -*-
00002 
00003 // Copyright (C) 2008, 2009 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 <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/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 
00081       friend bool
00082       operator==(thread::id __x, thread::id __y)
00083       { return __gthread_equal(__x._M_thread, __y._M_thread); }
00084 
00085       friend bool
00086       operator<(thread::id __x, thread::id __y)
00087       { return __x._M_thread < __y._M_thread; }
00088 
00089       template<class _CharT, class _Traits>
00090     friend basic_ostream<_CharT, _Traits>&
00091     operator<<(basic_ostream<_CharT, _Traits>&& __out, thread::id __id);
00092     };
00093 
00094     // Simple base type that the templatized, derived class containing
00095     // an arbitrary functor can be converted to and called.
00096     struct _Impl_base
00097     {
00098       __shared_base_type    _M_this_ptr;
00099 
00100       virtual ~_Impl_base() = default;
00101 
00102       virtual void _M_run() = 0;
00103     };
00104 
00105     template<typename _Callable>
00106       struct _Impl : public _Impl_base
00107       {
00108     _Callable       _M_func;
00109 
00110     _Impl(_Callable&& __f) : _M_func(std::forward<_Callable>(__f))
00111     { }
00112 
00113     void
00114     _M_run() { _M_func(); }
00115       };
00116 
00117   private:
00118     id              _M_id;
00119 
00120   public:
00121     thread() = default;
00122     thread(const thread&) = delete;
00123 
00124     thread(thread&& __t)
00125     { swap(__t); }
00126 
00127     template<typename _Callable>
00128       explicit thread(_Callable __f)
00129       { _M_start_thread(_M_make_routine<_Callable>(__f)); }
00130 
00131     template<typename _Callable, typename... _Args>
00132       thread(_Callable&& __f, _Args&&... __args)
00133       { _M_start_thread(_M_make_routine(std::bind(__f, __args...))); }
00134 
00135     ~thread()
00136     {
00137       if (joinable())
00138     std::terminate();
00139     }
00140 
00141     thread& operator=(const thread&) = delete;
00142 
00143     thread& operator=(thread&& __t)
00144     {
00145       if (joinable())
00146     std::terminate();
00147       swap(__t);
00148       return *this;
00149     }
00150 
00151     void
00152     swap(thread&& __t)
00153     { std::swap(_M_id, __t._M_id); }
00154 
00155     bool
00156     joinable() const
00157     { return !(_M_id == id()); }
00158 
00159     void
00160     join();
00161 
00162     void
00163     detach();
00164 
00165     thread::id
00166     get_id() const
00167     { return _M_id; }
00168 
00169     /** @pre thread is joinable
00170      */
00171     native_handle_type
00172     native_handle()
00173     { return _M_id._M_thread; }
00174 
00175     // Returns a value that hints at the number of hardware thread contexts.
00176     static unsigned int
00177     hardware_concurrency()
00178     { return 0; }
00179 
00180   private:
00181     void
00182     _M_start_thread(__shared_base_type);
00183 
00184     template<typename _Callable>
00185       shared_ptr<_Impl<_Callable>>
00186       _M_make_routine(_Callable&& __f)
00187       {
00188     // Create and allocate full data structure, not base.
00189     return make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
00190       }
00191   };
00192 
00193   inline void
00194   swap(thread& __x, thread& __y)
00195   { __x.swap(__y); }
00196 
00197   inline void
00198   swap(thread&& __x, thread& __y)
00199   { __x.swap(__y); }
00200 
00201   inline void
00202   swap(thread& __x, thread&& __y)
00203   { __x.swap(__y); }
00204 
00205   inline bool
00206   operator!=(thread::id __x, thread::id __y)
00207   { return !(__x == __y); }
00208 
00209   inline bool
00210   operator<=(thread::id __x, thread::id __y)
00211   { return !(__y < __x); }
00212 
00213   inline bool
00214   operator>(thread::id __x, thread::id __y)
00215   { return __y < __x; }
00216 
00217   inline bool
00218   operator>=(thread::id __x, thread::id __y)
00219   { return !(__x < __y); }
00220 
00221   template<class _CharT, class _Traits>
00222     inline basic_ostream<_CharT, _Traits>&
00223     operator<<(basic_ostream<_CharT, _Traits>&& __out, thread::id __id)
00224     {
00225       if (__id == thread::id())
00226     return __out << "thread::id of a non-executing thread";
00227       else
00228     return __out << __id._M_thread;
00229     }
00230 
00231   /** @namespace std::this_thread
00232    *  @brief ISO C++ 0x entities sub namespace for thread.
00233    *  30.2.2 Namespace this_thread.
00234    */
00235   namespace this_thread
00236   {
00237     /// get_id
00238     inline thread::id
00239     get_id() { return thread::id(__gthread_self()); }
00240 
00241 #ifdef _GLIBCXX_USE_SCHED_YIELD
00242     /// yield
00243     inline void
00244     yield()
00245     { __gthread_yield(); }
00246 #endif
00247 
00248 #ifdef _GLIBCXX_USE_NANOSLEEP
00249     /// sleep_until
00250     template<typename _Clock, typename _Duration>
00251       inline void
00252       sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
00253       { sleep_for(__atime - _Clock::now()); }
00254 
00255     /// sleep_for
00256     template<typename _Rep, typename _Period>
00257       inline void
00258       sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
00259       {
00260     chrono::seconds __s =
00261       chrono::duration_cast<chrono::seconds>(__rtime);
00262 
00263     chrono::nanoseconds __ns =
00264       chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
00265 
00266     __gthread_time_t __ts =
00267       {
00268         static_cast<std::time_t>(__s.count()),
00269         static_cast<long>(__ns.count())
00270       };
00271 
00272     ::nanosleep(&__ts, 0);
00273       }
00274 #endif
00275   }
00276 
00277   // @} group threads
00278 }
00279 
00280 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
00281 
00282 #endif // __GXX_EXPERIMENTAL_CXX0X__
00283 
00284 #endif // _GLIBCXX_THREAD

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