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
|
// **********************************************************************
//
// Copyright (c) 2003-2009 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************
#ifndef ICE_UTIL_STATIC_MUTEX_H
#define ICE_UTIL_STATIC_MUTEX_H
#include <IceUtil/Config.h>
#include <IceUtil/Lock.h>
#include <IceUtil/ThreadException.h>
#if defined(_MSC_VER) && (_MSC_VER < 1300)
//
// Old versions of the Platform SDK don't have InterlockedCompareExchangePointer
//
# ifndef InterlockedCompareExchangePointer
# define InterlockedCompareExchangePointer(Destination, ExChange, Comperand) \
InterlockedCompareExchange(Destination, ExChange, Comperand)
# endif
#endif
namespace IceUtil
{
//
// Forward declaration for friend.
//
class Cond;
//
// Simple non-recursive Mutex implementation.
// These mutexes are POD types (see ISO C++ 9(4) and 8.5.1) and must be
// initialized statically using ICE_STATIC_MUTEX_INITIALIZER.
//
//
class StaticMutex
{
public:
//
// Lock & TryLock typedefs.
//
typedef LockT<StaticMutex> Lock;
typedef TryLockT<StaticMutex> TryLock;
//
// Note that lock/tryLock & unlock in general should not be used
// directly. Instead use Lock & TryLock.
//
void lock() const;
//
// Returns true if the lock was acquired, and false otherwise.
//
bool tryLock() const;
void unlock() const;
#ifdef _WIN32
mutable CRITICAL_SECTION* _mutex;
#else
mutable pthread_mutex_t _mutex;
#endif
#if !defined(_MSC_VER) && !defined(__BCPLUSPLUS__)
// COMPILERBUG
// VC++ BC++ considers that aggregates should not have private members ...
// even if it's just functions.
private:
#endif
//
// LockState and the lock/unlock variations are for use by the
// Condition variable implementation.
//
#ifdef _WIN32
struct LockState
{
};
#else
struct LockState
{
pthread_mutex_t* mutex;
};
#endif
void unlock(LockState&) const;
void lock(LockState&) const;
#ifdef _WIN32
inline bool initialized() const;
ICE_UTIL_API void initialize() const;
#endif
#ifndef _MSC_VER
friend class Cond;
#endif
};
#ifdef _WIN32
# define ICE_STATIC_MUTEX_INITIALIZER { 0 }
#else
# define ICE_STATIC_MUTEX_INITIALIZER { PTHREAD_MUTEX_INITIALIZER }
#endif
// A "shared" global mutex that can be used for very simple tasks
// which should not lock any other mutexes.
//
extern ICE_UTIL_API StaticMutex globalMutex;
//
// For performance reasons the following functions are inlined.
//
#ifdef _WIN32
inline bool
StaticMutex::initialized() const
{
//
// Read mutex and then inserts a memory barrier to ensure we can't
// see tmp != 0 before we see the initialized object
//
void* tmp = _mutex;
return InterlockedCompareExchangePointer(reinterpret_cast<void**>(&tmp), 0, 0) != 0;
}
inline void
StaticMutex::lock() const
{
if(!initialized())
{
initialize();
}
EnterCriticalSection(_mutex);
assert(_mutex->RecursionCount == 1);
}
inline bool
StaticMutex::tryLock() const
{
if(!initialized())
{
initialize();
}
if(!TryEnterCriticalSection(_mutex))
{
return false;
}
if(_mutex->RecursionCount > 1)
{
LeaveCriticalSection(_mutex);
throw ThreadLockedException(__FILE__, __LINE__);
}
return true;
}
inline void
StaticMutex::unlock() const
{
assert(_mutex != 0);
assert(_mutex->RecursionCount == 1);
LeaveCriticalSection(_mutex);
}
inline void
StaticMutex::unlock(LockState&) const
{
assert(_mutex != 0);
assert(_mutex->RecursionCount == 1);
LeaveCriticalSection(_mutex);
}
inline void
StaticMutex::lock(LockState&) const
{
if(!initialized())
{
initialize();
}
EnterCriticalSection(_mutex);
}
#else
inline void
StaticMutex::lock() const
{
int rc = pthread_mutex_lock(&_mutex);
if(rc != 0)
{
if(rc == EDEADLK)
{
throw ThreadLockedException(__FILE__, __LINE__);
}
else
{
throw ThreadSyscallException(__FILE__, __LINE__, rc);
}
}
}
inline bool
StaticMutex::tryLock() const
{
int rc = pthread_mutex_trylock(&_mutex);
if(rc != 0 && rc != EBUSY)
{
if(rc == EDEADLK)
{
throw ThreadLockedException(__FILE__, __LINE__);
}
else
{
throw ThreadSyscallException(__FILE__, __LINE__, rc);
}
}
return (rc == 0);
}
inline void
StaticMutex::unlock() const
{
int rc = pthread_mutex_unlock(&_mutex);
if(rc != 0)
{
throw ThreadSyscallException(__FILE__, __LINE__, rc);
}
}
inline void
StaticMutex::unlock(LockState& state) const
{
state.mutex = &_mutex;
}
inline void
StaticMutex::lock(LockState&) const
{
}
#endif
} // End namespace IceUtil
#endif
|
