The C and C++ Include Header Files

/usr/include/c++/11/thread


$ cat -n /usr/include/c++/11/thread

     1	// <thread> -*- C++ -*-
     2	
     3	// Copyright (C) 2008-2021 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	#if __cplusplus > 201703L
    39	# include <compare>	// std::strong_ordering
    40	# include <stop_token>	// std::stop_source, std::stop_token, std::nostopstate
    41	#endif
    42	
    43	#include <bits/std_thread.h> // std::thread, get_id, yield
    44	#include <bits/this_thread_sleep.h> // std::this_thread::sleep_for, sleep_until
    45	
    46	namespace std _GLIBCXX_VISIBILITY(default)
    47	{
    48	_GLIBCXX_BEGIN_NAMESPACE_VERSION
    49	
    50	  /**
    51	   * @defgroup threads Threads
    52	   * @ingroup concurrency
    53	   *
    54	   * Classes for thread support.
    55	   * @{
    56	   */
    57	
    58	  // std::thread is defined in <bits/std_thread.h>
    59	
    60	#if __cpp_lib_three_way_comparison
    61	  inline strong_ordering
    62	  operator<=>(thread::id __x, thread::id __y) noexcept
    63	  { return __x._M_thread <=> __y._M_thread; }
    64	#else
    65	  inline bool
    66	  operator!=(thread::id __x, thread::id __y) noexcept
    67	  { return !(__x == __y); }
    68	
    69	  inline bool
    70	  operator<(thread::id __x, thread::id __y) noexcept
    71	  {
    72	    // Pthreads doesn't define any way to do this, so we just have to
    73	    // assume native_handle_type is LessThanComparable.
    74	    return __x._M_thread < __y._M_thread;
    75	  }
    76	
    77	  inline bool
    78	  operator<=(thread::id __x, thread::id __y) noexcept
    79	  { return !(__y < __x); }
    80	
    81	  inline bool
    82	  operator>(thread::id __x, thread::id __y) noexcept
    83	  { return __y < __x; }
    84	
    85	  inline bool
    86	  operator>=(thread::id __x, thread::id __y) noexcept
    87	  { return !(__x < __y); }
    88	#endif // __cpp_lib_three_way_comparison
    89	
    90	  template<class _CharT, class _Traits>
    91	    inline basic_ostream<_CharT, _Traits>&
    92	    operator<<(basic_ostream<_CharT, _Traits>& __out, thread::id __id)
    93	    {
    94	      if (__id == thread::id())
    95		return __out << "thread::id of a non-executing thread";
    96	      else
    97		return __out << __id._M_thread;
    98	    }
    99	
   100	#ifdef __cpp_lib_jthread
   101	
   102	  /// A thread that can be requested to stop and automatically joined.
   103	  class jthread
   104	  {
   105	  public:
   106	    using id = thread::id;
   107	    using native_handle_type = thread::native_handle_type;
   108	
   109	    jthread() noexcept
   110	    : _M_stop_source{nostopstate}
   111	    { }
   112	
   113	    template<typename _Callable, typename... _Args,
   114		     typename = enable_if_t<!is_same_v<remove_cvref_t<_Callable>,
   115						       jthread>>>
   116	      explicit
   117	      jthread(_Callable&& __f, _Args&&... __args)
   118	      : _M_thread{_S_create(_M_stop_source, std::forward<_Callable>(__f),
   119				    std::forward<_Args>(__args)...)}
   120	      { }
   121	
   122	    jthread(const jthread&) = delete;
   123	    jthread(jthread&&) noexcept = default;
   124	
   125	    ~jthread()
   126	    {
   127	      if (joinable())
   128	        {
   129	          request_stop();
   130	          join();
   131	        }
   132	    }
   133	
   134	    jthread&
   135	    operator=(const jthread&) = delete;
   136	
   137	    jthread&
   138	    operator=(jthread&& __other) noexcept
   139	    {
   140	      std::jthread(std::move(__other)).swap(*this);
   141	      return *this;
   142	    }
   143	
   144	    void
   145	    swap(jthread& __other) noexcept
   146	    {
   147	      std::swap(_M_stop_source, __other._M_stop_source);
   148	      std::swap(_M_thread, __other._M_thread);
   149	    }
   150	
   151	    [[nodiscard]] bool
   152	    joinable() const noexcept
   153	    {
   154	      return _M_thread.joinable();
   155	    }
   156	
   157	    void
   158	    join()
   159	    {
   160	      _M_thread.join();
   161	    }
   162	
   163	    void
   164	    detach()
   165	    {
   166	      _M_thread.detach();
   167	    }
   168	
   169	    [[nodiscard]] id
   170	    get_id() const noexcept
   171	    {
   172	      return _M_thread.get_id();
   173	    }
   174	
   175	    [[nodiscard]] native_handle_type
   176	    native_handle()
   177	    {
   178	      return _M_thread.native_handle();
   179	    }
   180	
   181	    [[nodiscard]] static unsigned
   182	    hardware_concurrency() noexcept
   183	    {
   184	      return thread::hardware_concurrency();
   185	    }
   186	
   187	    [[nodiscard]] stop_source
   188	    get_stop_source() noexcept
   189	    {
   190	      return _M_stop_source;
   191	    }
   192	
   193	    [[nodiscard]] stop_token
   194	    get_stop_token() const noexcept
   195	    {
   196	      return _M_stop_source.get_token();
   197	    }
   198	
   199	    bool request_stop() noexcept
   200	    {
   201	      return _M_stop_source.request_stop();
   202	    }
   203	
   204	    friend void swap(jthread& __lhs, jthread& __rhs) noexcept
   205	    {
   206	      __lhs.swap(__rhs);
   207	    }
   208	
   209	  private:
   210	    template<typename _Callable, typename... _Args>
   211	      static thread
   212	      _S_create(stop_source& __ssrc, _Callable&& __f, _Args&&... __args)
   213	      {
   214		if constexpr(is_invocable_v<decay_t<_Callable>, stop_token,
   215					    decay_t<_Args>...>)
   216		  return thread{std::forward<_Callable>(__f), __ssrc.get_token(),
   217				std::forward<_Args>(__args)...};
   218		else
   219		  {
   220		    static_assert(is_invocable_v<decay_t<_Callable>,
   221						 decay_t<_Args>...>,
   222				  "std::thread arguments must be invocable after"
   223				  " conversion to rvalues");
   224		    return thread{std::forward<_Callable>(__f),
   225				  std::forward<_Args>(__args)...};
   226		  }
   227	      }
   228	
   229	    stop_source _M_stop_source;
   230	    thread _M_thread;
   231	  };
   232	#endif // __cpp_lib_jthread
   233	
   234	  /// @} group threads
   235	
   236	_GLIBCXX_END_NAMESPACE_VERSION
   237	} // namespace
   238	#endif // C++11
   239	#endif // _GLIBCXX_THREAD