1// <thread> -*- C++ -*-
2
3// Copyright (C) 2008-2014 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#if __cplusplus < 201103L
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
47namespace 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;
65    typedef shared_ptr<_Impl_base>	__shared_base_type;
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>
91	friend basic_ostream<_CharT, _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    // _GLIBCXX_RESOLVE_LIB_DEFECTS
124    // 2097.  packaged_task constructors should be constrained
125    thread(thread&) = delete;
126    thread(const thread&) = delete;
127
128    thread(thread&& __t) noexcept
129    { swap(__t); }
130
131    template<typename _Callable, typename... _Args>
132      explicit
133      thread(_Callable&& __f, _Args&&... __args)
134      {
135        _M_start_thread(_M_make_routine(std::__bind_simple(
136                std::forward<_Callable>(__f),
137                std::forward<_Args>(__args)...)));
138      }
139
140    ~thread()
141    {
142      if (joinable())
143	std::terminate();
144    }
145
146    thread& operator=(const thread&) = delete;
147
148    thread& operator=(thread&& __t) noexcept
149    {
150      if (joinable())
151	std::terminate();
152      swap(__t);
153      return *this;
154    }
155
156    void
157    swap(thread& __t) noexcept
158    { std::swap(_M_id, __t._M_id); }
159
160    bool
161    joinable() const noexcept
162    { return !(_M_id == id()); }
163
164    void
165    join();
166
167    void
168    detach();
169
170    thread::id
171    get_id() const noexcept
172    { return _M_id; }
173
174    /** @pre thread is joinable
175     */
176    native_handle_type
177    native_handle()
178    { return _M_id._M_thread; }
179
180    // Returns a value that hints at the number of hardware thread contexts.
181    static unsigned int
182    hardware_concurrency() noexcept;
183
184  private:
185    void
186    _M_start_thread(__shared_base_type);
187
188    template<typename _Callable>
189      shared_ptr<_Impl<_Callable>>
190      _M_make_routine(_Callable&& __f)
191      {
192	// Create and allocate full data structure, not base.
193	return std::make_shared<_Impl<_Callable>>(std::forward<_Callable>(__f));
194      }
195  };
196
197  inline thread::_Impl_base::~_Impl_base() = default;
198
199  inline void
200  swap(thread& __x, thread& __y) noexcept
201  { __x.swap(__y); }
202
203  inline bool
204  operator!=(thread::id __x, thread::id __y) noexcept
205  { return !(__x == __y); }
206
207  inline bool
208  operator<=(thread::id __x, thread::id __y) noexcept
209  { return !(__y < __x); }
210
211  inline bool
212  operator>(thread::id __x, thread::id __y) noexcept
213  { return __y < __x; }
214
215  inline bool
216  operator>=(thread::id __x, thread::id __y) noexcept
217  { return !(__x < __y); }
218
219  // DR 889.
220  /// std::hash specialization for thread::id.
221  template<>
222    struct hash<thread::id>
223    : public __hash_base<size_t, thread::id>
224    {
225      size_t
226      operator()(const thread::id& __id) const noexcept
227      { return std::_Hash_impl::hash(__id._M_thread); }
228    };
229
230  template<class _CharT, class _Traits>
231    inline basic_ostream<_CharT, _Traits>&
232    operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
233    {
234      if (__id == thread::id())
235	return __out << "thread::id of a non-executing thread";
236      else
237	return __out << __id._M_thread;
238    }
239
240_GLIBCXX_END_NAMESPACE_VERSION
241
242  /** @namespace std::this_thread
243   *  @brief ISO C++ 2011 entities sub-namespace for thread.
244   *  30.3.2 Namespace this_thread.
245   */
246  namespace this_thread
247  {
248  _GLIBCXX_BEGIN_NAMESPACE_VERSION
249
250    /// get_id
251    inline thread::id
252    get_id() noexcept { return thread::id(__gthread_self()); }
253
254    /// yield
255    inline void
256    yield() noexcept
257    {
258#ifdef _GLIBCXX_USE_SCHED_YIELD
259      __gthread_yield();
260#endif
261    }
262
263    void
264    __sleep_for(chrono::seconds, chrono::nanoseconds);
265
266    /// sleep_for
267    template<typename _Rep, typename _Period>
268      inline void
269      sleep_for(const chrono::duration<_Rep, _Period>& __rtime)
270      {
271	if (__rtime <= __rtime.zero())
272	  return;
273	auto __s = chrono::duration_cast<chrono::seconds>(__rtime);
274	auto __ns = chrono::duration_cast<chrono::nanoseconds>(__rtime - __s);
275#ifdef _GLIBCXX_USE_NANOSLEEP
276	__gthread_time_t __ts =
277	  {
278	    static_cast<std::time_t>(__s.count()),
279	    static_cast<long>(__ns.count())
280	  };
281	::nanosleep(&__ts, 0);
282#else
283	__sleep_for(__s, __ns);
284#endif
285      }
286
287    /// sleep_until
288    template<typename _Clock, typename _Duration>
289      inline void
290      sleep_until(const chrono::time_point<_Clock, _Duration>& __atime)
291      {
292	auto __now = _Clock::now();
293	if (__now < __atime)
294	  sleep_for(__atime - __now);
295      }
296
297  _GLIBCXX_END_NAMESPACE_VERSION
298  }
299
300  // @} group threads
301
302} // namespace
303
304#endif // _GLIBCXX_HAS_GTHREADS && _GLIBCXX_USE_C99_STDINT_TR1
305
306#endif // C++11
307
308#endif // _GLIBCXX_THREAD
309