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
|
/**
* @file llthreadsafequeue.h
* @brief Base classes for thread, mutex and condition handling.
*
* $LicenseInfo:firstyear=2004&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#ifndef LL_LLTHREADSAFEQUEUE_H
#define LL_LLTHREADSAFEQUEUE_H
#include <string>
#include <stdexcept>
struct apr_pool_t; // From apr_pools.h
class LLThreadSafeQueueImplementation; // See below.
//
// A general queue exception.
//
class LL_COMMON_API LLThreadSafeQueueError:
public std::runtime_error
{
public:
LLThreadSafeQueueError(std::string const & message):
std::runtime_error(message)
{
; // No op.
}
};
//
// An exception raised when blocking operations are interrupted.
//
class LL_COMMON_API LLThreadSafeQueueInterrupt:
public LLThreadSafeQueueError
{
public:
LLThreadSafeQueueInterrupt(void):
LLThreadSafeQueueError("queue operation interrupted")
{
; // No op.
}
};
struct apr_queue_t; // From apr_queue.h
//
// Implementation details.
//
class LL_COMMON_API LLThreadSafeQueueImplementation
{
public:
LLThreadSafeQueueImplementation(apr_pool_t * pool, unsigned int capacity);
~LLThreadSafeQueueImplementation();
void pushFront(void * element);
bool tryPushFront(void * element);
void * popBack(void);
bool tryPopBack(void *& element);
size_t size();
private:
bool mOwnsPool;
apr_pool_t * mPool;
apr_queue_t * mQueue;
};
//
// Implements a thread safe FIFO.
//
template<typename ElementT>
class LLThreadSafeQueue
{
public:
typedef ElementT value_type;
// If the pool is set to NULL one will be allocated and managed by this
// queue.
LLThreadSafeQueue(apr_pool_t * pool = 0, unsigned int capacity = 1024);
// Add an element to the front of queue (will block if the queue has
// reached capacity).
//
// This call will raise an interrupt error if the queue is deleted while
// the caller is blocked.
void pushFront(ElementT const & element);
// Try to add an element to the front ofqueue without blocking. Returns
// true only if the element was actually added.
bool tryPushFront(ElementT const & element);
// Pop the element at the end of the queue (will block if the queue is
// empty).
//
// This call will raise an interrupt error if the queue is deleted while
// the caller is blocked.
ElementT popBack(void);
// Pop an element from the end of the queue if there is one available.
// Returns true only if an element was popped.
bool tryPopBack(ElementT & element);
// Returns the size of the queue.
size_t size();
private:
LLThreadSafeQueueImplementation mImplementation;
};
// LLThreadSafeQueue
//-----------------------------------------------------------------------------
template<typename ElementT>
LLThreadSafeQueue<ElementT>::LLThreadSafeQueue(apr_pool_t * pool, unsigned int capacity):
mImplementation(pool, capacity)
{
; // No op.
}
template<typename ElementT>
void LLThreadSafeQueue<ElementT>::pushFront(ElementT const & element)
{
ElementT * elementCopy = new ElementT(element);
try {
mImplementation.pushFront(elementCopy);
} catch (LLThreadSafeQueueInterrupt) {
delete elementCopy;
throw;
}
}
template<typename ElementT>
bool LLThreadSafeQueue<ElementT>::tryPushFront(ElementT const & element)
{
ElementT * elementCopy = new ElementT(element);
bool result = mImplementation.tryPushFront(elementCopy);
if(!result) delete elementCopy;
return result;
}
template<typename ElementT>
ElementT LLThreadSafeQueue<ElementT>::popBack(void)
{
ElementT * element = reinterpret_cast<ElementT *> (mImplementation.popBack());
ElementT result(*element);
delete element;
return result;
}
template<typename ElementT>
bool LLThreadSafeQueue<ElementT>::tryPopBack(ElementT & element)
{
void * storedElement;
bool result = mImplementation.tryPopBack(storedElement);
if(result) {
ElementT * elementPtr = reinterpret_cast<ElementT *>(storedElement);
element = *elementPtr;
delete elementPtr;
} else {
; // No op.
}
return result;
}
template<typename ElementT>
size_t LLThreadSafeQueue<ElementT>::size(void)
{
return mImplementation.size();
}
#endif
|
