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1   /*
2    * ====================================================================
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *   http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing,
14   * software distributed under the License is distributed on an
15   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16   * KIND, either express or implied.  See the License for the
17   * specific language governing permissions and limitations
18   * under the License.
19   * ====================================================================
20   *
21   * This software consists of voluntary contributions made by many
22   * individuals on behalf of the Apache Software Foundation.  For more
23   * information on the Apache Software Foundation, please see
24   * <http://www.apache.org/>.
25   *
26   */
27  
28  package org.apache.http.impl.client;
29  
30  import java.util.concurrent.ThreadFactory;
31  import java.util.concurrent.TimeUnit;
32  
33  import org.apache.http.conn.HttpClientConnectionManager;
34  import org.apache.http.util.Args;
35  
36  /**
37   * This class maintains a background thread to enforce an eviction policy for expired / idle
38   * persistent connections kept alive in the connection pool.
39   *
40   * @since 4.4
41   */
42  public final class IdleConnectionEvictor {
43  
44      private final HttpClientConnectionManager connectionManager;
45      private final ThreadFactory threadFactory;
46      private final Thread thread;
47      private final long sleepTimeMs;
48      private final long maxIdleTimeMs;
49  
50      private volatile Exception exception;
51  
52      public IdleConnectionEvictor(
53              final HttpClientConnectionManager connectionManager,
54              final ThreadFactory threadFactory,
55              final long sleepTime, final TimeUnit sleepTimeUnit,
56              final long maxIdleTime, final TimeUnit maxIdleTimeUnit) {
57          this.connectionManager = Args.notNull(connectionManager, "Connection manager");
58          this.threadFactory = threadFactory != null ? threadFactory : new DefaultThreadFactory();
59          this.sleepTimeMs = sleepTimeUnit != null ? sleepTimeUnit.toMillis(sleepTime) : sleepTime;
60          this.maxIdleTimeMs = maxIdleTimeUnit != null ? maxIdleTimeUnit.toMillis(maxIdleTime) : maxIdleTime;
61          this.thread = this.threadFactory.newThread(new Runnable() {
62              @Override
63              public void run() {
64                  try {
65                      while (!Thread.currentThread().isInterrupted()) {
66                          Thread.sleep(sleepTimeMs);
67                          connectionManager.closeExpiredConnections();
68                          if (maxIdleTimeMs > 0) {
69                              connectionManager.closeIdleConnections(maxIdleTimeMs, TimeUnit.MILLISECONDS);
70                          }
71                      }
72                  } catch (final Exception ex) {
73                      exception = ex;
74                  }
75  
76              }
77          });
78      }
79  
80      public IdleConnectionEvictor(
81              final HttpClientConnectionManager connectionManager,
82              final long sleepTime, final TimeUnit sleepTimeUnit,
83              final long maxIdleTime, final TimeUnit maxIdleTimeUnit) {
84          this(connectionManager, null, sleepTime, sleepTimeUnit, maxIdleTime, maxIdleTimeUnit);
85      }
86  
87      public IdleConnectionEvictor(
88              final HttpClientConnectionManager connectionManager,
89              final long maxIdleTime, final TimeUnit maxIdleTimeUnit) {
90          this(connectionManager, null,
91                  maxIdleTime > 0 ? maxIdleTime : 5, maxIdleTimeUnit != null ? maxIdleTimeUnit : TimeUnit.SECONDS,
92                  maxIdleTime, maxIdleTimeUnit);
93      }
94  
95      public void start() {
96          thread.start();
97      }
98  
99      public void shutdown() {
100         thread.interrupt();
101     }
102 
103     public boolean isRunning() {
104         return thread.isAlive();
105     }
106 
107     public void awaitTermination(final long time, final TimeUnit tunit) throws InterruptedException {
108         thread.join((tunit != null ? tunit : TimeUnit.MILLISECONDS).toMillis(time));
109     }
110 
111     static class DefaultThreadFactory implements ThreadFactory {
112 
113         @Override
114         public Thread newThread(final Runnable r) {
115             final Thread t = new Thread(r, "Connection evictor");
116             t.setDaemon(true);
117             return t;
118         }
119 
120     };
121 
122 
123 }