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1
8 package org.apache.avalon.excalibur.datasource;
9
10 import java.util.HashSet  ;
11 import java.util.Iterator ;
12 import org.apache.avalon.excalibur.concurrent.Lock;
13 import org.apache.avalon.excalibur.pool.DefaultPoolController;
14 import org.apache.avalon.excalibur.pool.HardResourceLimitingPool;
15 import org.apache.avalon.excalibur.pool.Poolable;
16 import org.apache.avalon.framework.activity.Disposable;
17 import org.apache.avalon.framework.activity.Initializable;
18
19
27 public class JdbcConnectionPool
28 extends HardResourceLimitingPool
29 implements Runnable , Disposable, Initializable
30 {
31 private Thread m_initThread;
32 private final boolean m_autoCommit;
33 private boolean m_noConnections = false;
34 private long m_wait = -1;
35 private HashSet m_waitingThreads = new HashSet ();
36
37 public JdbcConnectionPool( final JdbcConnectionFactory factory, final DefaultPoolController controller, final int min, final int max, final boolean autoCommit)
38 throws Exception
39 {
40 super(factory, controller, max);
41 m_min = min;
42
43 this.m_autoCommit = autoCommit;
44 }
45
46
52 public void setTimeout( long timeout )
53 {
54 if (this.m_initialized)
55 {
56 throw new IllegalStateException ("You cannot change the timeout after the pool is initialized");
57 }
58
59 m_wait = timeout;
60 }
61
62 public void initialize()
63 {
64 m_initThread = new Thread ( this );
65 m_initThread.start();
66 }
67
68 protected final Poolable newPoolable() throws Exception
69 {
70 JdbcConnection conn = null;
71
72 if ( m_wait < 1 )
73 {
74 conn = (JdbcConnection) super.newPoolable();
75 }
76 else
77 {
78 long curMillis = System.currentTimeMillis();
79 long endTime = curMillis + m_wait;
80 while ( ( null == conn ) && ( curMillis < endTime ) )
81 {
82 Object thread = Thread.currentThread();
83 m_waitingThreads.add(thread);
84
85 try
86 {
87 curMillis = System.currentTimeMillis();
88 m_mutex.release();
89
90 thread.wait( endTime - curMillis );
91 }
92 finally
93 {
94 m_mutex.acquire();
95 }
96
97 try
98 {
99 conn = (JdbcConnection) super.newPoolable();
100 }
101 finally
102 {
103 }
105 }
106 }
107
108 if (null == conn )
109 {
110 throw new NoAvailableConnectionException("All available connections are in use");
111 }
112
113 conn.setPool(this);
114 return conn;
115 }
116
117 public Poolable get()
118 throws Exception
119 {
120 if (! m_initialized)
121 {
122 if (m_noConnections)
123 {
124 throw new IllegalStateException ("There are no connections in the pool, check your settings.");
125 }
126 else if (m_initThread == null)
127 {
128 throw new IllegalStateException ("You cannot get a Connection before the pool is initialized.");
129 }
130 else
131 {
132 m_initThread.join();
133 }
134 }
135
136 JdbcConnection obj = (JdbcConnection) super.get();
137
138 if (obj.isClosed())
139 {
140 if (getLogger().isDebugEnabled())
141 {
142 getLogger().debug("JdbcConnection was closed, creating one to take its place");
143 }
144
145 try {
146 m_mutex.acquire();
147 if (m_active.contains(obj))
148 {
149 m_active.remove(obj);
150 }
151
152 this.removePoolable(obj);
153
154 obj = (JdbcConnection) this.newPoolable();
155
156 m_active.add(obj);
157 }
158 catch (Exception e)
159 {
160 if (getLogger().isWarnEnabled())
161 {
162 getLogger().warn("Could not get an open connection", e);
163 }
164 throw e;
165 }
166 finally
167 {
168 m_mutex.release();
169 }
170 }
171
172 if (obj.getAutoCommit() != m_autoCommit) {
173 obj.setAutoCommit(m_autoCommit);
174 }
175
176 return obj;
177 }
178
179 public void put( Poolable obj )
180 {
181 super.put( obj );
182 Iterator i = m_waitingThreads.iterator();
183 while (i.hasNext())
184 {
185 Object thread = i.next();
186 thread.notify();
187 i.remove();
188 }
189 }
190
191
192 public void run()
193 {
194 try {
195 this.grow(this.m_min);
196
197 if (this.size() > 0) {
198 m_initialized = true;
199 } else {
200 this.m_noConnections = true;
201
202 if (getLogger().isFatalErrorEnabled())
203 {
204 getLogger().fatalError("Excalibur could not create any connections. " +
205 "Examine your settings to make sure they are correct. " +
206 "Make sure you can connect with the same settings on your machine.");
207 }
208 }
209 } catch (Exception e) {
210 if (getLogger().isDebugEnabled())
211 {
212 getLogger().debug("Caught an exception during initialization", e);
213 }
214 }
215 }
216 }
217 |
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