1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
|
// Support for concurrent programing -*- C++ -*-
// Copyright (C) 2003-2012 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 =
#ifdef __GTHREADS
#if (defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2) \
&& defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4))
_S_atomic;
#else
_S_mutex;
#endif
#else
_S_single;
#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
|