libstdc++
thread
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1 // <thread> -*- C++ -*-
2 
3 // Copyright (C) 2008, 2009, 2010, 2011, 2012 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 <bits/functexcept.h>
42 #include <bits/functional_hash.h>
43 #include <bits/gthr.h>
44 
45 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
46 
47 namespace std _GLIBCXX_VISIBILITY(default)
48 {
49 _GLIBCXX_BEGIN_NAMESPACE_VERSION
50 
51  /**
52  * @defgroup threads Threads
53  * @ingroup concurrency
54  *
55  * Classes for thread support.
56  * @{
57  */
58 
59  /// thread
60  class thread
61  {
62  public:
63  typedef __gthread_t native_handle_type;
64  struct _Impl_base;
66 
67  /// thread::id
68  class id
69  {
70  native_handle_type _M_thread;
71 
72  public:
73  id() noexcept : _M_thread() { }
74 
75  explicit
76  id(native_handle_type __id) : _M_thread(__id) { }
77 
78  private:
79  friend class thread;
80  friend class hash<thread::id>;
81 
82  friend bool
83  operator==(thread::id __x, thread::id __y) noexcept
84  { return __gthread_equal(__x._M_thread, __y._M_thread); }
85 
86  friend bool
87  operator<(thread::id __x, thread::id __y) noexcept
88  { return __x._M_thread < __y._M_thread; }
89 
90  template<class _CharT, class _Traits>
92  operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id);
93  };
94 
95  // Simple base type that the templatized, derived class containing
96  // an arbitrary functor can be converted to and called.
97  struct _Impl_base
98  {
99  __shared_base_type _M_this_ptr;
100 
101  inline virtual ~_Impl_base();
102 
103  virtual void _M_run() = 0;
104  };
105 
106  template<typename _Callable>
107  struct _Impl : public _Impl_base
108  {
109  _Callable _M_func;
110 
111  _Impl(_Callable&& __f) : _M_func(std::forward<_Callable>(__f))
112  { }
113 
114  void
115  _M_run() { _M_func(); }
116  };
117 
118  private:
119  id _M_id;
120 
121  public:
122  thread() noexcept = default;
123  thread(thread&) = delete;
124  thread(const thread&) = delete;
125 
126  thread(thread&& __t) noexcept
127  { swap(__t); }
128 
129  template<typename _Callable, typename... _Args>
130  explicit
131  thread(_Callable&& __f, _Args&&... __args)
132  {
133  _M_start_thread(_M_make_routine(std::__bind_simple(
134  std::forward<_Callable>(__f),
135  std::forward<_Args>(__args)...)));
136  }
137 
138  ~thread()
139  {
140  if (joinable())
141  std::terminate();
142  }
143 
144  thread& operator=(const thread&) = delete;
145 
146  thread& operator=(thread&& __t) noexcept
147  {
148  if (joinable())
149  std::terminate();
150  swap(__t);
151  return *this;
152  }
153 
154  void
155  swap(thread& __t) noexcept
156  { std::swap(_M_id, __t._M_id); }
157 
158  bool
159  joinable() const noexcept
160  { return !(_M_id == id()); }
161 
162  void
163  join();
164 
165  void
166  detach();
167 
168  thread::id
169  get_id() const noexcept
170  { return _M_id; }
171 
172  /** @pre thread is joinable
173  */
174  native_handle_type
176  { return _M_id._M_thread; }
177 
178  // Returns a value that hints at the number of hardware thread contexts.
179  static unsigned int
180  hardware_concurrency() noexcept;
181 
182  private:
183  void
184  _M_start_thread(__shared_base_type);
185 
186  template<typename _Callable>
187  shared_ptr<_Impl<_Callable>>
188  _M_make_routine(_Callable&& __f)
189  {
190  // Create and allocate full data structure, not base.
191  return std::make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
192  }
193  };
194 
195  inline thread::_Impl_base::~_Impl_base() = default;
196 
197  inline void
198  swap(thread& __x, thread& __y) noexcept
199  { __x.swap(__y); }
200 
201  inline bool
202  operator!=(thread::id __x, thread::id __y) noexcept
203  { return !(__x == __y); }
204 
205  inline bool
206  operator<=(thread::id __x, thread::id __y) noexcept
207  { return !(__y < __x); }
208 
209  inline bool
210  operator>(thread::id __x, thread::id __y) noexcept
211  { return __y < __x; }
212 
213  inline bool
214  operator>=(thread::id __x, thread::id __y) noexcept
215  { return !(__x < __y); }
216 
217  // DR 889.
218  /// std::hash specialization for thread::id.
219  template<>
220  struct hash<thread::id>
221  : public __hash_base<size_t, thread::id>
222  {
223  size_t
224  operator()(const thread::id& __id) const noexcept
225  { return std::_Hash_impl::hash(__id._M_thread); }
226  };
227 
228  template<class _CharT, class _Traits>
230  operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
231  {
232  if (__id == thread::id())
233  return __out << "thread::id of a non-executing thread";
234  else
235  return __out << __id._M_thread;
236  }
237 
238 _GLIBCXX_END_NAMESPACE_VERSION
239 
240  /** @namespace std::this_thread
241  * @brief ISO C++ 0x entities sub namespace for thread.
242  * 30.2.2 Namespace this_thread.
243  */
244  namespace this_thread
245  {
246  _GLIBCXX_BEGIN_NAMESPACE_VERSION
247 
248  /// get_id
249  inline thread::id
250  get_id() noexcept { return thread::id(__gthread_self()); }
251 
252 #ifdef _GLIBCXX_USE_SCHED_YIELD
253  /// yield
254  inline void
255  yield() noexcept
256  { __gthread_yield(); }
257 #endif
258 
259 #ifdef _GLIBCXX_USE_NANOSLEEP
260  /// sleep_for
261  template<typename _Rep, typename _Period>
262  inline void
264  {
265  chrono::seconds __s =
267 
268  chrono::nanoseconds __ns =
270 
271  __gthread_time_t __ts =
272  {
273  static_cast<std::time_t>(__s.count()),
274  static_cast<long>(__ns.count())
275  };
276 
277  ::nanosleep(&__ts, 0);
278  }
279 
280  /// sleep_until
281  template<typename _Clock, typename _Duration>
282  inline void
284  { sleep_for(__atime - _Clock::now()); }
285 #endif
286 
287  _GLIBCXX_END_NAMESPACE_VERSION
288  }
289 
290  // @} group threads
291 
292 } // namespace
293 
294 #endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
295 
296 #endif // __GXX_EXPERIMENTAL_CXX0X__
297 
298 #endif // _GLIBCXX_THREAD