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The C and C++ Include Header Files

cat -n /usr/include/c++/15/ext/concurrence.h

     1	// Support for concurrent programing -*- C++ -*-
     2	
     3	// Copyright (C) 2003-2025 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 ext/concurrence.h
    26	 *  This file is a GNU extension to the Standard C++ Library.
    27	 */
    28	
    29	#ifndef _CONCURRENCE_H
    30	#define _CONCURRENCE_H 1
    31	
    32	#ifdef _GLIBCXX_SYSHDR
    33	#pragma GCC system_header
    34	#endif
    35	
    36	#include <exception>
    37	#include <bits/gthr.h>
    38	#include <bits/functexcept.h>
    39	#include <bits/cpp_type_traits.h>
    40	#include <ext/type_traits.h>
    41	
    42	#pragma GCC diagnostic push
    43	#pragma GCC diagnostic ignored "-Wc++11-extensions"
    44	
    45	namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
    46	{
    47	_GLIBCXX_BEGIN_NAMESPACE_VERSION
    48	
    49	  // Available locking policies:
    50	  // _S_single    single-threaded code that doesn't need to be locked.
    51	  // _S_mutex     multi-threaded code that requires additional support
    52	  //              from gthr.h or abstraction layers in concurrence.h.
    53	  // _S_atomic    multi-threaded code using atomic operations.
    54	  enum _Lock_policy { _S_single, _S_mutex, _S_atomic };
    55	
    56	  // Compile time constant that indicates prefered locking policy in
    57	  // the current configuration.
    58	  _GLIBCXX17_INLINE const _Lock_policy __default_lock_policy =
    59	#ifndef __GTHREADS
    60	  _S_single;
    61	#elif defined _GLIBCXX_HAVE_ATOMIC_LOCK_POLICY
    62	  _S_atomic;
    63	#else
    64	  _S_mutex;
    65	#endif
    66	
    67	  // NB: As this is used in libsupc++, need to only depend on
    68	  // exception. No stdexception classes, no use of std::string.
    69	  class __concurrence_lock_error : public std::exception
    70	  {
    71	  public:
    72	    virtual char const*
    73	    what() const throw()
    74	    { return "__gnu_cxx::__concurrence_lock_error"; }
    75	  };
    76	
    77	  class __concurrence_unlock_error : public std::exception
    78	  {
    79	  public:
    80	    virtual char const*
    81	    what() const throw()
    82	    { return "__gnu_cxx::__concurrence_unlock_error"; }
    83	  };
    84	
    85	  class __concurrence_broadcast_error : public std::exception
    86	  {
    87	  public:
    88	    virtual char const*
    89	    what() const throw()
    90	    { return "__gnu_cxx::__concurrence_broadcast_error"; }
    91	  };
    92	
    93	  class __concurrence_wait_error : public std::exception
    94	  {
    95	  public:
    96	    virtual char const*
    97	    what() const throw()
    98	    { return "__gnu_cxx::__concurrence_wait_error"; }
    99	  };
   100	
   101	  // Substitute for concurrence_error object in the case of -fno-exceptions.
   102	  inline void
   103	  __throw_concurrence_lock_error()
   104	  { _GLIBCXX_THROW_OR_ABORT(__concurrence_lock_error()); }
   105	
   106	  inline void
   107	  __throw_concurrence_unlock_error()
   108	  { _GLIBCXX_THROW_OR_ABORT(__concurrence_unlock_error()); }
   109	
   110	#ifdef __GTHREAD_HAS_COND
   111	  inline void
   112	  __throw_concurrence_broadcast_error()
   113	  { _GLIBCXX_THROW_OR_ABORT(__concurrence_broadcast_error()); }
   114	
   115	  inline void
   116	  __throw_concurrence_wait_error()
   117	  { _GLIBCXX_THROW_OR_ABORT(__concurrence_wait_error()); }
   118	#endif
   119	
   120	  class __mutex
   121	  {
   122	  private:
   123	#if __GTHREADS && defined __GTHREAD_MUTEX_INIT
   124	    __gthread_mutex_t _M_mutex = __GTHREAD_MUTEX_INIT;
   125	#else
   126	    __gthread_mutex_t _M_mutex;
   127	#endif
   128	
   129	    __mutex(const __mutex&);
   130	    __mutex& operator=(const __mutex&);
   131	
   132	  public:
   133	    __mutex()
   134	    {
   135	#if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT
   136	      if (__gthread_active_p())
   137		__GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex);
   138	#endif
   139	    }
   140	
   141	#if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT
   142	    ~__mutex()
   143	    {
   144	      if (__gthread_active_p())
   145		__gthread_mutex_destroy(&_M_mutex);
   146	    }
   147	#endif
   148	
   149	    void lock()
   150	    {
   151	#if __GTHREADS
   152	      if (__gthread_active_p())
   153		{
   154		  if (__gthread_mutex_lock(&_M_mutex) != 0)
   155		    __throw_concurrence_lock_error();
   156		}
   157	#endif
   158	    }
   159	
   160	    void unlock()
   161	    {
   162	#if __GTHREADS
   163	      if (__gthread_active_p())
   164		{
   165		  if (__gthread_mutex_unlock(&_M_mutex) != 0)
   166		    __throw_concurrence_unlock_error();
   167		}
   168	#endif
   169	    }
   170	
   171	    __gthread_mutex_t* gthread_mutex(void)
   172	      { return &_M_mutex; }
   173	  };
   174	
   175	  class __recursive_mutex
   176	  {
   177	  private:
   178	#if __GTHREADS && defined __GTHREAD_RECURSIVE_MUTEX_INIT
   179	    __gthread_recursive_mutex_t _M_mutex = __GTHREAD_RECURSIVE_MUTEX_INIT;
   180	#else
   181	    __gthread_recursive_mutex_t _M_mutex;
   182	#endif
   183	
   184	    __recursive_mutex(const __recursive_mutex&);
   185	    __recursive_mutex& operator=(const __recursive_mutex&);
   186	
   187	  public:
   188	    __recursive_mutex()
   189	    {
   190	#if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT
   191	      if (__gthread_active_p())
   192		__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex);
   193	#endif
   194	    }
   195	
   196	#if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT
   197	    ~__recursive_mutex()
   198	    {
   199	      if (__gthread_active_p())
   200		__gthread_recursive_mutex_destroy(&_M_mutex);
   201	    }
   202	#endif
   203	
   204	    void lock()
   205	    {
   206	#if __GTHREADS
   207	      if (__gthread_active_p())
   208		{
   209		  if (__gthread_recursive_mutex_lock(&_M_mutex) != 0)
   210		    __throw_concurrence_lock_error();
   211		}
   212	#endif
   213	    }
   214	
   215	    void unlock()
   216	    {
   217	#if __GTHREADS
   218	      if (__gthread_active_p())
   219		{
   220		  if (__gthread_recursive_mutex_unlock(&_M_mutex) != 0)
   221		    __throw_concurrence_unlock_error();
   222		}
   223	#endif
   224	    }
   225	
   226	    __gthread_recursive_mutex_t* gthread_recursive_mutex(void)
   227	    { return &_M_mutex; }
   228	  };
   229	
   230	  /// Scoped lock idiom.
   231	  // Acquire the mutex here with a constructor call, then release with
   232	  // the destructor call in accordance with RAII style.
   233	  class __scoped_lock
   234	  {
   235	  public:
   236	    typedef __mutex __mutex_type;
   237	
   238	  private:
   239	    __mutex_type& _M_device;
   240	
   241	    __scoped_lock(const __scoped_lock&);
   242	    __scoped_lock& operator=(const __scoped_lock&);
   243	
   244	  public:
   245	    explicit __scoped_lock(__mutex_type& __name) : _M_device(__name)
   246	    { _M_device.lock(); }
   247	
   248	    ~__scoped_lock() throw()
   249	    { _M_device.unlock(); }
   250	  };
   251	
   252	#ifdef __GTHREAD_HAS_COND
   253	  class __cond
   254	  {
   255	  private:
   256	#if __GTHREADS && defined __GTHREAD_COND_INIT
   257	    __gthread_cond_t _M_cond = __GTHREAD_COND_INIT;
   258	#else
   259	    __gthread_cond_t _M_cond;
   260	#endif
   261	
   262	    __cond(const __cond&);
   263	    __cond& operator=(const __cond&);
   264	
   265	  public:
   266	    __cond()
   267	    {
   268	#if __GTHREADS && ! defined __GTHREAD_COND_INIT
   269	      if (__gthread_active_p())
   270		__GTHREAD_COND_INIT_FUNCTION(&_M_cond);
   271	#endif
   272	    }
   273	
   274	#if __GTHREADS && ! defined __GTHREAD_COND_INIT
   275	    ~__cond()
   276	    {
   277	      if (__gthread_active_p())
   278		__gthread_cond_destroy(&_M_cond);
   279	    }
   280	#endif
   281	
   282	    void broadcast()
   283	    {
   284	#if __GTHREADS
   285	      if (__gthread_active_p())
   286		{
   287		  if (__gthread_cond_broadcast(&_M_cond) != 0)
   288		    __throw_concurrence_broadcast_error();
   289		}
   290	#endif
   291	    }
   292	
   293	    void wait(__mutex *mutex)
   294	    {
   295	#if __GTHREADS
   296	      {
   297		  if (__gthread_cond_wait(&_M_cond, mutex->gthread_mutex()) != 0)
   298		    __throw_concurrence_wait_error();
   299	      }
   300	#endif
   301	    }
   302	
   303	    void wait_recursive(__recursive_mutex *mutex)
   304	    {
   305	#if __GTHREADS
   306	      {
   307		  if (__gthread_cond_wait_recursive(&_M_cond,
   308						    mutex->gthread_recursive_mutex())
   309		      != 0)
   310		    __throw_concurrence_wait_error();
   311	      }
   312	#endif
   313	    }
   314	  };
   315	#endif
   316	
   317	_GLIBCXX_END_NAMESPACE_VERSION
   318	} // namespace
   319	
   320	#pragma GCC diagnostic pop
   321	
   322	#endif