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comparison Orthanc/Core/MultiThreading/SharedMessageQueue.cpp @ 25:15acbf5e7545

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refactoring
author Sebastien Jodogne <s.jodogne@gmail.com>
date Tue, 02 Jun 2015 11:16:30 +0200
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children 3809121c3290
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24:ed9acb0f938e 25:15acbf5e7545
1 /**
2 * Orthanc - A Lightweight, RESTful DICOM Store
3 * Copyright (C) 2012-2015 Sebastien Jodogne, Medical Physics
4 * Department, University Hospital of Liege, Belgium
5 *
6 * This program is free software: you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation, either version 3 of the
9 * License, or (at your option) any later version.
10 *
11 * In addition, as a special exception, the copyright holders of this
12 * program give permission to link the code of its release with the
13 * OpenSSL project's "OpenSSL" library (or with modified versions of it
14 * that use the same license as the "OpenSSL" library), and distribute
15 * the linked executables. You must obey the GNU General Public License
16 * in all respects for all of the code used other than "OpenSSL". If you
17 * modify file(s) with this exception, you may extend this exception to
18 * your version of the file(s), but you are not obligated to do so. If
19 * you do not wish to do so, delete this exception statement from your
20 * version. If you delete this exception statement from all source files
21 * in the program, then also delete it here.
22 *
23 * This program is distributed in the hope that it will be useful, but
24 * WITHOUT ANY WARRANTY; without even the implied warranty of
25 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
26 * General Public License for more details.
27 *
28 * You should have received a copy of the GNU General Public License
29 * along with this program. If not, see <http://www.gnu.org/licenses/>.
30 **/
31
32
33 #include "../PrecompiledHeaders.h"
34 #include "SharedMessageQueue.h"
35
36
37
38 /**
39 * FIFO (queue):
40 *
41 * back front
42 * +--+--+--+--+--+--+--+--+--+--+--+
43 * Enqueue -> | | | | | | | | | | | |
44 * | | | | | | | | | | | | -> Dequeue
45 * +--+--+--+--+--+--+--+--+--+--+--+
46 * ^
47 * |
48 * Make room here
49 *
50 *
51 * LIFO (stack):
52 *
53 * back front
54 * +--+--+--+--+--+--+--+--+--+--+--+
55 * | | | | | | | | | | | | <- Enqueue
56 * | | | | | | | | | | | | -> Dequeue
57 * +--+--+--+--+--+--+--+--+--+--+--+
58 * ^
59 * |
60 * Make room here
61 **/
62
63
64 namespace Orthanc
65 {
66 SharedMessageQueue::SharedMessageQueue(unsigned int maxSize) :
67 isFifo_(true),
68 maxSize_(maxSize)
69 {
70 }
71
72
73 SharedMessageQueue::~SharedMessageQueue()
74 {
75 for (Queue::iterator it = queue_.begin(); it != queue_.end(); ++it)
76 {
77 delete *it;
78 }
79 }
80
81
82 void SharedMessageQueue::Enqueue(IDynamicObject* message)
83 {
84 boost::mutex::scoped_lock lock(mutex_);
85
86 if (maxSize_ != 0 && queue_.size() > maxSize_)
87 {
88 if (isFifo_)
89 {
90 // Too many elements in the queue: Make room
91 delete queue_.front();
92 queue_.pop_front();
93 }
94 else
95 {
96 // Too many elements in the stack: Make room
97 delete queue_.back();
98 queue_.pop_back();
99 }
100 }
101
102 if (isFifo_)
103 {
104 // Queue policy (FIFO)
105 queue_.push_back(message);
106 }
107 else
108 {
109 // Stack policy (LIFO)
110 queue_.push_front(message);
111 }
112
113 elementAvailable_.notify_one();
114 }
115
116
117 IDynamicObject* SharedMessageQueue::Dequeue(int32_t millisecondsTimeout)
118 {
119 boost::mutex::scoped_lock lock(mutex_);
120
121 // Wait for a message to arrive in the FIFO queue
122 while (queue_.empty())
123 {
124 if (millisecondsTimeout == 0)
125 {
126 elementAvailable_.wait(lock);
127 }
128 else
129 {
130 bool success = elementAvailable_.timed_wait
131 (lock, boost::posix_time::milliseconds(millisecondsTimeout));
132 if (!success)
133 {
134 return NULL;
135 }
136 }
137 }
138
139 std::auto_ptr<IDynamicObject> message(queue_.front());
140 queue_.pop_front();
141
142 if (queue_.empty())
143 {
144 emptied_.notify_all();
145 }
146
147 return message.release();
148 }
149
150
151
152 bool SharedMessageQueue::WaitEmpty(int32_t millisecondsTimeout)
153 {
154 boost::mutex::scoped_lock lock(mutex_);
155
156 // Wait for the queue to become empty
157 while (!queue_.empty())
158 {
159 if (millisecondsTimeout == 0)
160 {
161 emptied_.wait(lock);
162 }
163 else
164 {
165 if (!emptied_.timed_wait
166 (lock, boost::posix_time::milliseconds(millisecondsTimeout)))
167 {
168 return false;
169 }
170 }
171 }
172
173 return true;
174 }
175
176
177 void SharedMessageQueue::SetFifoPolicy()
178 {
179 boost::mutex::scoped_lock lock(mutex_);
180 isFifo_ = true;
181 }
182
183 void SharedMessageQueue::SetLifoPolicy()
184 {
185 boost::mutex::scoped_lock lock(mutex_);
186 isFifo_ = false;
187 }
188 }