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
|
// -*- C++ -*-
//==========================================================================
/**
* @file Recursive_Thread_Mutex.h
*
* $Id$
*
* Moved from Synch.h.
*
* @author Douglas C. Schmidt <schmidt@cs.wustl.edu> and
* Abdullah Sowayan <abdullah.sowayan@lmco.com>
*/
//==========================================================================
#ifndef ACE_RECURSIVE_THREAD_MUTEX_H
#define ACE_RECURSIVE_THREAD_MUTEX_H
#include /**/ "ace/pre.h"
#include /**/ "ace/ACE_export.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
#if !defined (ACE_HAS_THREADS)
# include "ace/Null_Mutex.h"
#else /* ACE_HAS_THREADS */
// ACE platform supports some form of threading.
#include "ace/OS_NS_Thread.h"
ACE_BEGIN_VERSIONED_NAMESPACE_DECL
/**
* @class ACE_Recursive_Thread_Mutex
*
* @brief Implement a C++ wrapper that allows nested acquisition and
* release of a mutex that occurs in the same thread.
*/
class ACE_Export ACE_Recursive_Thread_Mutex
{
public:
/// Initialize a recursive mutex.
ACE_Recursive_Thread_Mutex (const ACE_TCHAR *name = 0,
ACE_mutexattr_t *arg = 0);
/// Implicitly release a recursive mutex.
~ACE_Recursive_Thread_Mutex (void);
/**
* Implicitly release a recursive mutex. Note that only one thread
* should call this method since it doesn't protect against race
* conditions.
*/
int remove (void);
/**
* Acquire a recursive mutex (will increment the nesting level and
* not deadmutex if the owner of the mutex calls this method more
* than once).
*/
int acquire (void);
/**
* Block the thread until we acquire the mutex or until @a tv times
* out, in which case -1 is returned with <errno> == <ETIME>. Note
* that @a tv is assumed to be in "absolute" rather than "relative"
* time. The value of @a tv is updated upon return to show the
* actual (absolute) acquisition time.
*/
int acquire (ACE_Time_Value &tv);
/**
* If <tv> == 0 the call <acquire()> directly. Otherwise, Block the
* thread until we acquire the mutex or until <tv> times out, in
* which case -1 is returned with <errno> == <ETIME>. Note that
* <*tv> is assumed to be in "absolute" rather than "relative" time.
* The value of <*tv> is updated upon return to show the actual
* (absolute) acquisition time.
*/
int acquire (ACE_Time_Value *tv);
/**
* Conditionally acquire a recursive mutex (i.e., won't block).
* Returns -1 on failure. If we "failed" because someone else
* already had the lock, <errno> is set to <EBUSY>.
*/
int tryacquire (void);
/**
* Acquire mutex ownership. This calls <acquire> and is only
* here to make the <ACE_Recusive_Thread_Mutex> interface consistent
* with the other synchronization APIs.
*/
int acquire_read (void);
/**
* Acquire mutex ownership. This calls <acquire> and is only
* here to make the <ACE_Recusive_Thread_Mutex> interface consistent
* with the other synchronization APIs.
*/
int acquire_write (void);
/**
* Conditionally acquire mutex (i.e., won't block). This calls
* <tryacquire> and is only here to make the
* <ACE_Recusive_Thread_Mutex> interface consistent with the other
* synchronization APIs. Returns -1 on failure. If we "failed"
* because someone else already had the lock, <errno> is set to
* <EBUSY>.
*/
int tryacquire_read (void);
/**
* Conditionally acquire mutex (i.e., won't block). This calls
* <tryacquire> and is only here to make the
* <ACE_Recusive_Thread_Mutex> interface consistent with the other
* synchronization APIs. Returns -1 on failure. If we "failed"
* because someone else already had the lock, <errno> is set to
* <EBUSY>.
*/
int tryacquire_write (void);
/**
* This is only here to make the ACE_Recursive_Thread_Mutex
* interface consistent with the other synchronization APIs.
* Assumes the caller has already acquired the mutex using one of
* the above calls, and returns 0 (success) always.
*/
int tryacquire_write_upgrade (void);
/**
* Releases a recursive mutex (will not release mutex until all the
* nesting level drops to 0, which means the mutex is no longer
* held).
*/
int release (void);
/// Return the id of the thread that currently owns the mutex.
ACE_thread_t get_thread_id (void);
/**
* Return the nesting level of the recursion. When a thread has
* acquired the mutex for the first time, the nesting level == 1.
* The nesting level is incremented every time the thread acquires
* the mutex recursively. Note that if the ACE_HAS_RECURSIVE_MUTEXES
* macro is enabled then this method may return -1 on platforms that
* do not expose the internal count.
*/
int get_nesting_level (void);
/// Returns a reference to the recursive mutex;
ACE_recursive_thread_mutex_t &mutex (void);
/// Returns a reference to the recursive mutex's internal mutex;
ACE_thread_mutex_t &get_nesting_mutex (void);
/// Dump the state of an object.
void dump (void) const;
/// Declare the dynamic allocation hooks.
ACE_ALLOC_HOOK_DECLARE;
protected:
// = This method should *not* be public (they hold no locks...)
void set_thread_id (ACE_thread_t t);
/// Recursive mutex.
ACE_recursive_thread_mutex_t lock_;
/// Keeps track of whether <remove> has been called yet to avoid
/// multiple <remove> calls, e.g., explicitly and implicitly in the
/// destructor. This flag isn't protected by a lock, so make sure
/// that you don't have multiple threads simultaneously calling
/// <remove> on the same object, which is a bad idea anyway...
bool removed_;
private:
// = Prevent assignment and initialization.
void operator= (const ACE_Recursive_Thread_Mutex &);
ACE_Recursive_Thread_Mutex (const ACE_Recursive_Thread_Mutex &);
};
ACE_END_VERSIONED_NAMESPACE_DECL
#if defined (__ACE_INLINE__)
#include "ace/Recursive_Thread_Mutex.inl"
#endif /* __ACE_INLINE__ */
#endif /* !ACE_HAS_THREADS */
#include /**/ "ace/post.h"
#endif /* ACE_RECURSIVE_THREAD_MUTEX_H */
|
