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
|
// @file mutex.h
/* Copyright 2009 10gen Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#ifdef _WIN32
#include "mongo/platform/windows_basic.h"
#endif
#include <boost/noncopyable.hpp>
#include <boost/thread/mutex.hpp>
#include <boost/thread/xtime.hpp>
#include "mongo/util/assert_util.h"
#include "mongo/util/heapcheck.h"
#include "mongo/util/concurrency/threadlocal.h"
#if defined(_DEBUG)
#include "mongo/util/concurrency/mutexdebugger.h"
#endif
namespace mongo {
inline boost::xtime incxtimemillis( long long s ) {
boost::xtime xt;
boost::xtime_get(&xt, boost::TIME_UTC_);
xt.sec += (int)( s / 1000 );
xt.nsec += (int)(( s % 1000 ) * 1000000);
if ( xt.nsec >= 1000000000 ) {
xt.nsec -= 1000000000;
xt.sec++;
}
return xt;
}
// If you create a local static instance of this class, that instance will be destroyed
// before all global static objects are destroyed, so _destroyingStatics will be set
// to true before the global static variables are destroyed.
class StaticObserver : boost::noncopyable {
public:
static bool _destroyingStatics;
~StaticObserver() { _destroyingStatics = true; }
};
/** On pthread systems, it is an error to destroy a mutex while held (boost mutex
* may use pthread). Static global mutexes may be held upon shutdown in our
* implementation, and this way we avoid destroying them.
* NOT recursive.
*/
class mutex : boost::noncopyable {
public:
const char * const _name;
mutex(const char *name) : _name(name)
{
_m = new boost::timed_mutex();
IGNORE_OBJECT( _m ); // Turn-off heap checking on _m
}
~mutex() {
if( !StaticObserver::_destroyingStatics ) {
UNIGNORE_OBJECT( _m );
delete _m;
}
}
class try_lock : boost::noncopyable {
public:
try_lock( mongo::mutex &m , int millis = 0 )
: _l( m.boost() , incxtimemillis( millis ) ) ,
ok( _l.owns_lock() )
{ }
private:
boost::timed_mutex::scoped_timed_lock _l;
public:
const bool ok;
};
class scoped_lock : boost::noncopyable {
public:
#if defined(_DEBUG)
struct PostStaticCheck {
PostStaticCheck();
} _check;
mongo::mutex * const _mut;
#endif
scoped_lock( mongo::mutex &m ) :
#if defined(_DEBUG)
_mut(&m),
#endif
_l( m.boost() ) {
#if defined(_DEBUG)
mutexDebugger.entering(_mut->_name);
#endif
}
~scoped_lock() {
#if defined(_DEBUG)
mutexDebugger.leaving(_mut->_name);
#endif
}
boost::timed_mutex::scoped_lock &boost() { return _l; }
private:
boost::timed_mutex::scoped_lock _l;
};
private:
boost::timed_mutex &boost() { return *_m; }
boost::timed_mutex *_m;
};
typedef mongo::mutex::scoped_lock scoped_lock;
/** The concept with SimpleMutex is that it is a basic lock/unlock with no
special functionality (such as try and try timeout). Thus it can be
implemented using OS-specific facilities in all environments (if desired).
On Windows, the implementation below is faster than boost mutex.
*/
#if defined(_WIN32)
class SimpleMutex : boost::noncopyable {
public:
SimpleMutex( const char * ) { InitializeCriticalSection( &_cs ); }
void dassertLocked() const { }
void lock() { EnterCriticalSection( &_cs ); }
void unlock() { LeaveCriticalSection( &_cs ); }
class scoped_lock {
SimpleMutex& _m;
public:
scoped_lock( SimpleMutex &m ) : _m(m) { _m.lock(); }
~scoped_lock() { _m.unlock(); }
const SimpleMutex& m() const { return _m; }
};
private:
CRITICAL_SECTION _cs;
};
#else
class SimpleMutex : boost::noncopyable {
public:
void dassertLocked() const { }
SimpleMutex(const char* name) { verify( pthread_mutex_init(&_lock,0) == 0 ); }
~SimpleMutex(){
if ( ! StaticObserver::_destroyingStatics ) {
verify( pthread_mutex_destroy(&_lock) == 0 );
}
}
void lock() { verify( pthread_mutex_lock(&_lock) == 0 ); }
void unlock() { verify( pthread_mutex_unlock(&_lock) == 0 ); }
public:
class scoped_lock : boost::noncopyable {
SimpleMutex& _m;
public:
scoped_lock( SimpleMutex &m ) : _m(m) { _m.lock(); }
~scoped_lock() { _m.unlock(); }
const SimpleMutex& m() const { return _m; }
};
private:
pthread_mutex_t _lock;
};
#endif
/** This can be used instead of boost recursive mutex. The advantage is the _DEBUG checks
* and ability to assertLocked(). This has not yet been tested for speed vs. the boost one.
*/
class RecursiveMutex : boost::noncopyable {
public:
RecursiveMutex(const char* name) : m(name) { }
bool isLocked() const { return n.get() > 0; }
class scoped_lock : boost::noncopyable {
RecursiveMutex& rm;
int& nLocksByMe;
public:
scoped_lock( RecursiveMutex &m ) : rm(m), nLocksByMe(rm.n.getRef()) {
if( nLocksByMe++ == 0 )
rm.m.lock();
}
~scoped_lock() {
verify( nLocksByMe > 0 );
if( --nLocksByMe == 0 ) {
rm.m.unlock();
}
}
};
private:
SimpleMutex m;
ThreadLocalValue<int> n;
};
}
|
