libstdc++
thread
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00001 // <thread> -*- C++ -*-
00002 
00003 // Copyright (C) 2008-2015 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 include/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 #if __cplusplus < 201103L
00035 # include <bits/c++0x_warning.h>
00036 #else
00037 
00038 #include <chrono>
00039 #include <functional>
00040 #include <memory>
00041 #include <bits/functexcept.h>
00042 #include <bits/functional_hash.h>
00043 #include <bits/gthr.h>
00044 
00045 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
00046 
00047 namespace std _GLIBCXX_VISIBILITY(default)
00048 {
00049 _GLIBCXX_BEGIN_NAMESPACE_VERSION
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() noexcept : _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) noexcept
00084       { return __gthread_equal(__x._M_thread, __y._M_thread); }
00085 
00086       friend bool
00087       operator<(thread::id __x, thread::id __y) noexcept
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() noexcept = default;
00123     // _GLIBCXX_RESOLVE_LIB_DEFECTS
00124     // 2097.  packaged_task constructors should be constrained
00125     thread(thread&) = delete;
00126     thread(const thread&) = delete;
00127 
00128     thread(thread&& __t) noexcept
00129     { swap(__t); }
00130 
00131     template<typename _Callable, typename... _Args>
00132       explicit 
00133       thread(_Callable&& __f, _Args&&... __args)
00134       {
00135 #ifdef GTHR_ACTIVE_PROXY
00136         // Create a reference to pthread_create, not just the gthr weak symbol
00137         _M_start_thread(_M_make_routine(std::__bind_simple(
00138                 std::forward<_Callable>(__f),
00139                 std::forward<_Args>(__args)...)),
00140             reinterpret_cast<void(*)()>(&pthread_create));
00141 #else
00142         _M_start_thread(_M_make_routine(std::__bind_simple(
00143                 std::forward<_Callable>(__f),
00144                 std::forward<_Args>(__args)...)));
00145 #endif
00146       }
00147 
00148     ~thread()
00149     {
00150       if (joinable())
00151         std::terminate();
00152     }
00153 
00154     thread& operator=(const thread&) = delete;
00155 
00156     thread& operator=(thread&& __t) noexcept
00157     {
00158       if (joinable())
00159         std::terminate();
00160       swap(__t);
00161       return *this;
00162     }
00163 
00164     void
00165     swap(thread& __t) noexcept
00166     { std::swap(_M_id, __t._M_id); }
00167 
00168     bool
00169     joinable() const noexcept
00170     { return !(_M_id == id()); }
00171 
00172     void
00173     join();
00174 
00175     void
00176     detach();
00177 
00178     thread::id
00179     get_id() const noexcept
00180     { return _M_id; }
00181 
00182     /** @pre thread is joinable
00183      */
00184     native_handle_type
00185     native_handle()
00186     { return _M_id._M_thread; }
00187 
00188     // Returns a value that hints at the number of hardware thread contexts.
00189     static unsigned int
00190     hardware_concurrency() noexcept;
00191 
00192   private:
00193     void
00194     _M_start_thread(__shared_base_type, void (*)());
00195 
00196     void
00197     _M_start_thread(__shared_base_type);
00198 
00199     template<typename _Callable>
00200       shared_ptr<_Impl<_Callable>>
00201       _M_make_routine(_Callable&& __f)
00202       {
00203         // Create and allocate full data structure, not base.
00204         return std::make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
00205       }
00206   };
00207 
00208   inline thread::_Impl_base::~_Impl_base() = default;
00209 
00210   inline void
00211   swap(thread& __x, thread& __y) noexcept
00212   { __x.swap(__y); }
00213 
00214   inline bool
00215   operator!=(thread::id __x, thread::id __y) noexcept
00216   { return !(__x == __y); }
00217 
00218   inline bool
00219   operator<=(thread::id __x, thread::id __y) noexcept
00220   { return !(__y < __x); }
00221 
00222   inline bool
00223   operator>(thread::id __x, thread::id __y) noexcept
00224   { return __y < __x; }
00225 
00226   inline bool
00227   operator>=(thread::id __x, thread::id __y) noexcept
00228   { return !(__x < __y); }
00229 
00230   // DR 889.
00231   /// std::hash specialization for thread::id.
00232   template<>
00233     struct hash<thread::id>
00234     : public __hash_base<size_t, thread::id>
00235     {
00236       size_t
00237       operator()(const thread::id& __id) const noexcept
00238       { return std::_Hash_impl::hash(__id._M_thread); }
00239     };
00240 
00241   template<class _CharT, class _Traits>
00242     inline basic_ostream<_CharT, _Traits>&
00243     operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
00244     {
00245       if (__id == thread::id())
00246         return __out << "thread::id of a non-executing thread";
00247       else
00248         return __out << __id._M_thread;
00249     }
00250 
00251 _GLIBCXX_END_NAMESPACE_VERSION
00252 
00253   /** @namespace std::this_thread
00254    *  @brief ISO C++ 2011 entities sub-namespace for thread.
00255    *  30.3.2 Namespace this_thread.
00256    */
00257   namespace this_thread
00258   {
00259   _GLIBCXX_BEGIN_NAMESPACE_VERSION
00260 
00261     /// get_id
00262     inline thread::id
00263     get_id() noexcept { return thread::id(__gthread_self()); }
00264 
00265     /// yield
00266     inline void
00267     yield() noexcept
00268     {
00269 #ifdef _GLIBCXX_USE_SCHED_YIELD
00270       __gthread_yield();
00271 #endif
00272     }
00273 
00274     void
00275     __sleep_for(chrono::seconds, chrono::nanoseconds);
00276 
00277     /// sleep_for
00278     template<typename _Rep, typename _Period>
00279       inline void
00280       sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
00281       {
00282         if (__rtime <= __rtime.zero())
00283           return;
00284         auto __s = chrono::duration_cast<chrono::seconds>(__rtime);
00285         auto __ns = chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
00286 #ifdef _GLIBCXX_USE_NANOSLEEP
00287         __gthread_time_t __ts =
00288           {
00289             static_cast<std::time_t>(__s.count()),
00290             static_cast<long>(__ns.count())
00291           };
00292         ::nanosleep(&__ts, 0);
00293 #else
00294         __sleep_for(__s, __ns);
00295 #endif
00296       }
00297 
00298     /// sleep_until
00299     template<typename _Clock, typename _Duration>
00300       inline void
00301       sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
00302       {
00303         auto __now = _Clock::now();
00304         if (__now < __atime)
00305           sleep_for(__atime - __now);
00306       }
00307 
00308   _GLIBCXX_END_NAMESPACE_VERSION
00309   }
00310 
00311   // @} group threads
00312 
00313 } // namespace
00314 
00315 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
00316 
00317 #endif // C++11
00318 
00319 #endif // _GLIBCXX_THREAD