11.2.0/ext/concurrence.h

// Support for concurrent programing -*- C++ -*-

// Copyright (C) 2003-2021 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file ext/concurrence.h
 *  This file is a GNU extension to the Standard C++ Library.
 */

#ifndef _CONCURRENCE_H
#define _CONCURRENCE_H 1

#pragma GCC system_header

#include <exception>
#include <bits/gthr.h> 
#include <bits/functexcept.h>
#include <bits/cpp_type_traits.h>
#include <ext/type_traits.h>

namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  // Available locking policies:
  // _S_single    single-threaded code that doesn't need to be locked.
  // _S_mutex     multi-threaded code that requires additional support
  //              from gthr.h or abstraction layers in concurrence.h.
  // _S_atomic    multi-threaded code using atomic operations.
  enum _Lock_policy { _S_single, _S_mutex, _S_atomic }; 

  // Compile time constant that indicates prefered locking policy in
  // the current configuration.
  static const _Lock_policy __default_lock_policy = 
#ifndef __GTHREADS
  _S_single;
#elif defined _GLIBCXX_HAVE_ATOMIC_LOCK_POLICY
  _S_atomic;
#else
  _S_mutex;
#endif

  // NB: As this is used in libsupc++, need to only depend on
  // exception. No stdexception classes, no use of std::string.
  class __concurrence_lock_error : public std::exception
  {
  public:
    virtual char const*
    what() const throw()
    { return "__gnu_cxx::__concurrence_lock_error"; }
  };

  class __concurrence_unlock_error : public std::exception
  {
  public:
    virtual char const*
    what() const throw()
    { return "__gnu_cxx::__concurrence_unlock_error"; }
  };

  class __concurrence_broadcast_error : public std::exception
  {
  public:
    virtual char const*
    what() const throw()
    { return "__gnu_cxx::__concurrence_broadcast_error"; }
  };

  class __concurrence_wait_error : public std::exception
  {
  public:
    virtual char const*
    what() const throw()
    { return "__gnu_cxx::__concurrence_wait_error"; }
  };

  // Substitute for concurrence_error object in the case of -fno-exceptions.
  inline void
  __throw_concurrence_lock_error()
  { _GLIBCXX_THROW_OR_ABORT(__concurrence_lock_error()); }

  inline void
  __throw_concurrence_unlock_error()
  { _GLIBCXX_THROW_OR_ABORT(__concurrence_unlock_error()); }

#ifdef __GTHREAD_HAS_COND
  inline void
  __throw_concurrence_broadcast_error()
  { _GLIBCXX_THROW_OR_ABORT(__concurrence_broadcast_error()); }

  inline void
  __throw_concurrence_wait_error()
  { _GLIBCXX_THROW_OR_ABORT(__concurrence_wait_error()); }
#endif
 
  class __mutex 
  {
  private:
#if __GTHREADS && defined __GTHREAD_MUTEX_INIT
    __gthread_mutex_t _M_mutex = __GTHREAD_MUTEX_INIT;
#else
    __gthread_mutex_t _M_mutex;
#endif

    __mutex(const __mutex&);
    __mutex& operator=(const __mutex&);

  public:
    __mutex() 
    { 
#if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT
      if (__gthread_active_p())
        __GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex);
#endif
    }

#if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT
    ~__mutex() 
    { 
      if (__gthread_active_p())
        __gthread_mutex_destroy(&_M_mutex); 
    }
#endif 

    void lock()
    {
#if __GTHREADS
      if (__gthread_active_p())
        {
          if (__gthread_mutex_lock(&_M_mutex) != 0)
            __throw_concurrence_lock_error();
        }
#endif
    }
    
    void unlock()
    {
#if __GTHREADS
      if (__gthread_active_p())
        {
          if (__gthread_mutex_unlock(&_M_mutex) != 0)
            __throw_concurrence_unlock_error();
        }
#endif
    }

    __gthread_mutex_t* gthread_mutex(void)
      { return &_M_mutex; }
  };

  class __recursive_mutex 
  {
  private:
#if __GTHREADS && defined __GTHREAD_RECURSIVE_MUTEX_INIT
    __gthread_recursive_mutex_t _M_mutex = __GTHREAD_RECURSIVE_MUTEX_INIT;
#else
    __gthread_recursive_mutex_t _M_mutex;
#endif

    __recursive_mutex(const __recursive_mutex&);
    __recursive_mutex& operator=(const __recursive_mutex&);

  public:
    __recursive_mutex() 
    { 
#if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT
      if (__gthread_active_p())
        __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex);
#endif
    }

#if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT
    ~__recursive_mutex()
    {
      if (__gthread_active_p())
        __gthread_recursive_mutex_destroy(&_M_mutex);
    }
#endif

    void lock()
    { 
#if __GTHREADS
      if (__gthread_active_p())
        {
          if (__gthread_recursive_mutex_lock(&_M_mutex) != 0)
            __throw_concurrence_lock_error();
        }
#endif
    }
    
    void unlock()
    { 
#if __GTHREADS
      if (__gthread_active_p())
        {
          if (__gthread_recursive_mutex_unlock(&_M_mutex) != 0)
            __throw_concurrence_unlock_error();
        }
#endif
    }

    __gthread_recursive_mutex_t* gthread_recursive_mutex(void)
    { return &_M_mutex; }
  };

  /// Scoped lock idiom.
  // Acquire the mutex here with a constructor call, then release with
  // the destructor call in accordance with RAII style.
  class __scoped_lock
  {
  public:
    typedef __mutex __mutex_type;

  private:
    __mutex_type& _M_device;

    __scoped_lock(const __scoped_lock&);
    __scoped_lock& operator=(const __scoped_lock&);

  public:
    explicit __scoped_lock(__mutex_type& __name) : _M_device(__name)
    { _M_device.lock(); }

    ~__scoped_lock() throw()
    { _M_device.unlock(); }
  };

#ifdef __GTHREAD_HAS_COND
  class __cond
  {
  private:
#if __GTHREADS && defined __GTHREAD_COND_INIT
    __gthread_cond_t _M_cond = __GTHREAD_COND_INIT;
#else
    __gthread_cond_t _M_cond;
#endif

    __cond(const __cond&);
    __cond& operator=(const __cond&);

  public:
    __cond() 
    { 
#if __GTHREADS && ! defined __GTHREAD_COND_INIT
      if (__gthread_active_p())
        __GTHREAD_COND_INIT_FUNCTION(&_M_cond);
#endif
    }

#if __GTHREADS && ! defined __GTHREAD_COND_INIT
    ~__cond() 
    { 
      if (__gthread_active_p())
        __gthread_cond_destroy(&_M_cond); 
    }
#endif 

    void broadcast()
    {
#if __GTHREADS
      if (__gthread_active_p())
        {
          if (__gthread_cond_broadcast(&_M_cond) != 0)
            __throw_concurrence_broadcast_error();
        }
#endif
    }

    void wait(__mutex *mutex)
    {
#if __GTHREADS
      {
          if (__gthread_cond_wait(&_M_cond, mutex->gthread_mutex()) != 0)
            __throw_concurrence_wait_error();
      }
#endif
    }

    void wait_recursive(__recursive_mutex *mutex)
    {
#if __GTHREADS
      {
          if (__gthread_cond_wait_recursive(&_M_cond,
                                            mutex->gthread_recursive_mutex())
              != 0)
            __throw_concurrence_wait_error();
      }
#endif
    }
  };
#endif

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

#endif
Revision:	1166
Committed:	Tue Oct 26 14:22:36 2021 UTC (4 years ago) by rossy
Content type:	text/x-chdr
File size:	7542 byte(s)
Log Message:	Daodan: Replace MinGW build env with an up-to-date MSYS2 env
#	Content
1	// Support for concurrent programing -- C++ --
2
3	// Copyright (C) 2003-2021 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 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	#pragma GCC system_header
33
34	#include <exception>
35	#include <bits/gthr.h>
36	#include <bits/functexcept.h>
37	#include <bits/cpp_type_traits.h>
38	#include <ext/type_traits.h>
39
40	namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
41	{
42	_GLIBCXX_BEGIN_NAMESPACE_VERSION
43
44	// Available locking policies:
45	// _S_single single-threaded code that doesn't need to be locked.
46	// _S_mutex multi-threaded code that requires additional support
47	// from gthr.h or abstraction layers in concurrence.h.
48	// _S_atomic multi-threaded code using atomic operations.
49	enum _Lock_policy { _S_single, _S_mutex, _S_atomic };
50
51	// Compile time constant that indicates prefered locking policy in
52	// the current configuration.
53	static const _Lock_policy __default_lock_policy =
54	#ifndef __GTHREADS
55	_S_single;
56	#elif defined _GLIBCXX_HAVE_ATOMIC_LOCK_POLICY
57	_S_atomic;
58	#else
59	_S_mutex;
60	#endif
61
62	// NB: As this is used in libsupc++, need to only depend on
63	// exception. No stdexception classes, no use of std::string.
64	class __concurrence_lock_error : public std::exception
65	{
66	public:
67	virtual char const*
68	what() const throw()
69	{ return "__gnu_cxx::__concurrence_lock_error"; }
70	};
71
72	class __concurrence_unlock_error : public std::exception
73	{
74	public:
75	virtual char const*
76	what() const throw()
77	{ return "__gnu_cxx::__concurrence_unlock_error"; }
78	};
79
80	class __concurrence_broadcast_error : public std::exception
81	{
82	public:
83	virtual char const*
84	what() const throw()
85	{ return "__gnu_cxx::__concurrence_broadcast_error"; }
86	};
87
88	class __concurrence_wait_error : public std::exception
89	{
90	public:
91	virtual char const*
92	what() const throw()
93	{ return "__gnu_cxx::__concurrence_wait_error"; }
94	};
95
96	// Substitute for concurrence_error object in the case of -fno-exceptions.
97	inline void
98	__throw_concurrence_lock_error()
99	{ _GLIBCXX_THROW_OR_ABORT(__concurrence_lock_error()); }
100
101	inline void
102	__throw_concurrence_unlock_error()
103	{ _GLIBCXX_THROW_OR_ABORT(__concurrence_unlock_error()); }
104
105	#ifdef __GTHREAD_HAS_COND
106	inline void
107	__throw_concurrence_broadcast_error()
108	{ _GLIBCXX_THROW_OR_ABORT(__concurrence_broadcast_error()); }
109
110	inline void
111	__throw_concurrence_wait_error()
112	{ _GLIBCXX_THROW_OR_ABORT(__concurrence_wait_error()); }
113	#endif
114
115	class __mutex
116	{
117	private:
118	#if __GTHREADS && defined __GTHREAD_MUTEX_INIT
119	__gthread_mutex_t _M_mutex = __GTHREAD_MUTEX_INIT;
120	#else
121	__gthread_mutex_t _M_mutex;
122	#endif
123
124	__mutex(const __mutex&);
125	__mutex& operator=(const __mutex&);
126
127	public:
128	__mutex()
129	{
130	#if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT
131	if (__gthread_active_p())
132	__GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex);
133	#endif
134	}
135
136	#if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT
137	~__mutex()
138	{
139	if (__gthread_active_p())
140	__gthread_mutex_destroy(&_M_mutex);
141	}
142	#endif
143
144	void lock()
145	{
146	#if __GTHREADS
147	if (__gthread_active_p())
148	{
149	if (__gthread_mutex_lock(&_M_mutex) != 0)
150	__throw_concurrence_lock_error();
151	}
152	#endif
153	}
154
155	void unlock()
156	{
157	#if __GTHREADS
158	if (__gthread_active_p())
159	{
160	if (__gthread_mutex_unlock(&_M_mutex) != 0)
161	__throw_concurrence_unlock_error();
162	}
163	#endif
164	}
165
166	__gthread_mutex_t* gthread_mutex(void)
167	{ return &_M_mutex; }
168	};
169
170	class __recursive_mutex
171	{
172	private:
173	#if __GTHREADS && defined __GTHREAD_RECURSIVE_MUTEX_INIT
174	__gthread_recursive_mutex_t _M_mutex = __GTHREAD_RECURSIVE_MUTEX_INIT;
175	#else
176	__gthread_recursive_mutex_t _M_mutex;
177	#endif
178
179	__recursive_mutex(const __recursive_mutex&);
180	__recursive_mutex& operator=(const __recursive_mutex&);
181
182	public:
183	__recursive_mutex()
184	{
185	#if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT
186	if (__gthread_active_p())
187	__GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex);
188	#endif
189	}
190
191	#if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT
192	~__recursive_mutex()
193	{
194	if (__gthread_active_p())
195	__gthread_recursive_mutex_destroy(&_M_mutex);
196	}
197	#endif
198
199	void lock()
200	{
201	#if __GTHREADS
202	if (__gthread_active_p())
203	{
204	if (__gthread_recursive_mutex_lock(&_M_mutex) != 0)
205	__throw_concurrence_lock_error();
206	}
207	#endif
208	}
209
210	void unlock()
211	{
212	#if __GTHREADS
213	if (__gthread_active_p())
214	{
215	if (__gthread_recursive_mutex_unlock(&_M_mutex) != 0)
216	__throw_concurrence_unlock_error();
217	}
218	#endif
219	}
220
221	__gthread_recursive_mutex_t* gthread_recursive_mutex(void)
222	{ return &_M_mutex; }
223	};
224
225	/// Scoped lock idiom.
226	// Acquire the mutex here with a constructor call, then release with
227	// the destructor call in accordance with RAII style.
228	class __scoped_lock
229	{
230	public:
231	typedef __mutex __mutex_type;
232
233	private:
234	__mutex_type& _M_device;
235
236	__scoped_lock(const __scoped_lock&);
237	__scoped_lock& operator=(const __scoped_lock&);
238
239	public:
240	explicit __scoped_lock(__mutex_type& __name) : _M_device(__name)
241	{ _M_device.lock(); }
242
243	~__scoped_lock() throw()
244	{ _M_device.unlock(); }
245	};
246
247	#ifdef __GTHREAD_HAS_COND
248	class __cond
249	{
250	private:
251	#if __GTHREADS && defined __GTHREAD_COND_INIT
252	__gthread_cond_t _M_cond = __GTHREAD_COND_INIT;
253	#else
254	__gthread_cond_t _M_cond;
255	#endif
256
257	__cond(const __cond&);
258	__cond& operator=(const __cond&);
259
260	public:
261	__cond()
262	{
263	#if __GTHREADS && ! defined __GTHREAD_COND_INIT
264	if (__gthread_active_p())
265	__GTHREAD_COND_INIT_FUNCTION(&_M_cond);
266	#endif
267	}
268
269	#if __GTHREADS && ! defined __GTHREAD_COND_INIT
270	~__cond()
271	{
272	if (__gthread_active_p())
273	__gthread_cond_destroy(&_M_cond);
274	}
275	#endif
276
277	void broadcast()
278	{
279	#if __GTHREADS
280	if (__gthread_active_p())
281	{
282	if (__gthread_cond_broadcast(&_M_cond) != 0)
283	__throw_concurrence_broadcast_error();
284	}
285	#endif
286	}
287
288	void wait(__mutex *mutex)
289	{
290	#if __GTHREADS
291	{
292	if (__gthread_cond_wait(&_M_cond, mutex->gthread_mutex()) != 0)
293	__throw_concurrence_wait_error();
294	}
295	#endif
296	}
297
298	void wait_recursive(__recursive_mutex *mutex)
299	{
300	#if __GTHREADS
301	{
302	if (__gthread_cond_wait_recursive(&_M_cond,
303	mutex->gthread_recursive_mutex())
304	!= 0)
305	__throw_concurrence_wait_error();
306	}
307	#endif
308	}
309	};
310	#endif
311
312	_GLIBCXX_END_NAMESPACE_VERSION
313	} // namespace
314
315	#endif