1 // Support for concurrent programing -*- C++ -*-
3 // Copyright (C) 2003-2018 Free Software Foundation, Inc.
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)
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.
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.
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/>.
25 /** @file ext/concurrence.h
26 * This file is a GNU extension to the Standard C++ Library.
29 #ifndef _CONCURRENCE_H
30 #define _CONCURRENCE_H 1
32 #pragma GCC system_header
35 #include <bits/gthr.h>
36 #include <bits/functexcept.h>
37 #include <bits/cpp_type_traits.h>
38 #include <ext/type_traits.h>
40 namespace __gnu_cxx
_GLIBCXX_VISIBILITY(default)
42 _GLIBCXX_BEGIN_NAMESPACE_VERSION
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
};
51 // Compile time constant that indicates prefered locking policy in
52 // the current configuration.
53 static const _Lock_policy __default_lock_policy
=
55 #if (defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2) \
56 && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4))
65 // NB: As this is used in libsupc++, need to only depend on
66 // exception. No stdexception classes, no use of std::string.
67 class __concurrence_lock_error
: public std::exception
72 { return "__gnu_cxx::__concurrence_lock_error"; }
75 class __concurrence_unlock_error
: public std::exception
80 { return "__gnu_cxx::__concurrence_unlock_error"; }
83 class __concurrence_broadcast_error
: public std::exception
88 { return "__gnu_cxx::__concurrence_broadcast_error"; }
91 class __concurrence_wait_error
: public std::exception
96 { return "__gnu_cxx::__concurrence_wait_error"; }
99 // Substitute for concurrence_error object in the case of -fno-exceptions.
101 __throw_concurrence_lock_error()
102 { _GLIBCXX_THROW_OR_ABORT(__concurrence_lock_error()); }
105 __throw_concurrence_unlock_error()
106 { _GLIBCXX_THROW_OR_ABORT(__concurrence_unlock_error()); }
108 #ifdef __GTHREAD_HAS_COND
110 __throw_concurrence_broadcast_error()
111 { _GLIBCXX_THROW_OR_ABORT(__concurrence_broadcast_error()); }
114 __throw_concurrence_wait_error()
115 { _GLIBCXX_THROW_OR_ABORT(__concurrence_wait_error()); }
121 #if __GTHREADS && defined __GTHREAD_MUTEX_INIT
122 __gthread_mutex_t _M_mutex
= __GTHREAD_MUTEX_INIT
;
124 __gthread_mutex_t _M_mutex
;
127 __mutex(const __mutex
&);
128 __mutex
& operator=(const __mutex
&);
133 #if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT
134 if (__gthread_active_p())
135 __GTHREAD_MUTEX_INIT_FUNCTION(&_M_mutex
);
139 #if __GTHREADS && ! defined __GTHREAD_MUTEX_INIT
142 if (__gthread_active_p())
143 __gthread_mutex_destroy(&_M_mutex
);
150 if (__gthread_active_p())
152 if (__gthread_mutex_lock(&_M_mutex
) != 0)
153 __throw_concurrence_lock_error();
161 if (__gthread_active_p())
163 if (__gthread_mutex_unlock(&_M_mutex
) != 0)
164 __throw_concurrence_unlock_error();
169 __gthread_mutex_t
* gthread_mutex(void)
170 { return &_M_mutex
; }
173 class __recursive_mutex
176 #if __GTHREADS && defined __GTHREAD_RECURSIVE_MUTEX_INIT
177 __gthread_recursive_mutex_t _M_mutex
= __GTHREAD_RECURSIVE_MUTEX_INIT
;
179 __gthread_recursive_mutex_t _M_mutex
;
182 __recursive_mutex(const __recursive_mutex
&);
183 __recursive_mutex
& operator=(const __recursive_mutex
&);
188 #if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT
189 if (__gthread_active_p())
190 __GTHREAD_RECURSIVE_MUTEX_INIT_FUNCTION(&_M_mutex
);
194 #if __GTHREADS && ! defined __GTHREAD_RECURSIVE_MUTEX_INIT
197 if (__gthread_active_p())
198 __gthread_recursive_mutex_destroy(&_M_mutex
);
205 if (__gthread_active_p())
207 if (__gthread_recursive_mutex_lock(&_M_mutex
) != 0)
208 __throw_concurrence_lock_error();
216 if (__gthread_active_p())
218 if (__gthread_recursive_mutex_unlock(&_M_mutex
) != 0)
219 __throw_concurrence_unlock_error();
224 __gthread_recursive_mutex_t
* gthread_recursive_mutex(void)
225 { return &_M_mutex
; }
228 /// Scoped lock idiom.
229 // Acquire the mutex here with a constructor call, then release with
230 // the destructor call in accordance with RAII style.
234 typedef __mutex __mutex_type
;
237 __mutex_type
& _M_device
;
239 __scoped_lock(const __scoped_lock
&);
240 __scoped_lock
& operator=(const __scoped_lock
&);
243 explicit __scoped_lock(__mutex_type
& __name
) : _M_device(__name
)
244 { _M_device
.lock(); }
246 ~__scoped_lock() throw()
247 { _M_device
.unlock(); }
250 #ifdef __GTHREAD_HAS_COND
254 #if __GTHREADS && defined __GTHREAD_COND_INIT
255 __gthread_cond_t _M_cond
= __GTHREAD_COND_INIT
;
257 __gthread_cond_t _M_cond
;
260 __cond(const __cond
&);
261 __cond
& operator=(const __cond
&);
266 #if __GTHREADS && ! defined __GTHREAD_COND_INIT
267 if (__gthread_active_p())
268 __GTHREAD_COND_INIT_FUNCTION(&_M_cond
);
272 #if __GTHREADS && ! defined __GTHREAD_COND_INIT
275 if (__gthread_active_p())
276 __gthread_cond_destroy(&_M_cond
);
283 if (__gthread_active_p())
285 if (__gthread_cond_broadcast(&_M_cond
) != 0)
286 __throw_concurrence_broadcast_error();
291 void wait(__mutex
*mutex
)
295 if (__gthread_cond_wait(&_M_cond
, mutex
->gthread_mutex()) != 0)
296 __throw_concurrence_wait_error();
301 void wait_recursive(__recursive_mutex
*mutex
)
305 if (__gthread_cond_wait_recursive(&_M_cond
,
306 mutex
->gthread_recursive_mutex())
308 __throw_concurrence_wait_error();
315 _GLIBCXX_END_NAMESPACE_VERSION