Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
EvictionTimer |
|
| 1.3333333333333333;1.333 | ||||
EvictionTimer$1 |
|
| 1.3333333333333333;1.333 | ||||
EvictionTimer$PrivilegedGetTccl |
|
| 1.3333333333333333;1.333 | ||||
EvictionTimer$PrivilegedSetTccl |
|
| 1.3333333333333333;1.333 |
1 | /* | |
2 | * Licensed to the Apache Software Foundation (ASF) under one or more | |
3 | * contributor license agreements. See the NOTICE file distributed with | |
4 | * this work for additional information regarding copyright ownership. | |
5 | * The ASF licenses this file to You under the Apache License, Version 2.0 | |
6 | * (the "License"); you may not use this file except in compliance with | |
7 | * the License. You may obtain a copy of the License at | |
8 | * | |
9 | * http://www.apache.org/licenses/LICENSE-2.0 | |
10 | * | |
11 | * Unless required by applicable law or agreed to in writing, software | |
12 | * distributed under the License is distributed on an "AS IS" BASIS, | |
13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
14 | * See the License for the specific language governing permissions and | |
15 | * limitations under the License. | |
16 | */ | |
17 | ||
18 | package org.apache.commons.pool.impl; | |
19 | ||
20 | import java.security.AccessController; | |
21 | import java.security.PrivilegedAction; | |
22 | import java.util.Timer; | |
23 | import java.util.TimerTask; | |
24 | ||
25 | /** | |
26 | * <p> | |
27 | * Provides a shared idle object eviction timer for all pools. This class wraps | |
28 | * the standard {@link Timer} and keeps track of how many pools are using it. | |
29 | * If no pools are using the timer, it is canceled. This prevents a thread | |
30 | * being left running which, in application server environments, can lead to | |
31 | * memory leads and/or prevent applications from shutting down or reloading | |
32 | * cleanly. | |
33 | * </p> | |
34 | * <p> | |
35 | * This class has package scope to prevent its inclusion in the pool public API. | |
36 | * The class declaration below should *not* be changed to public. | |
37 | * </p> | |
38 | */ | |
39 | class EvictionTimer { | |
40 | ||
41 | /** Timer instance */ | |
42 | private static Timer _timer; //@GuardedBy("this") | |
43 | ||
44 | /** Static usage count tracker */ | |
45 | private static int _usageCount; //@GuardedBy("this") | |
46 | ||
47 | /** Prevent instantiation */ | |
48 | 0 | private EvictionTimer() { |
49 | // Hide the default constuctor | |
50 | 0 | } |
51 | ||
52 | /** | |
53 | * Add the specified eviction task to the timer. Tasks that are added with a | |
54 | * call to this method *must* call {@link #cancel(TimerTask)} to cancel the | |
55 | * task to prevent memory and/or thread leaks in application server | |
56 | * environments. | |
57 | * @param task Task to be scheduled | |
58 | * @param delay Delay in milliseconds before task is executed | |
59 | * @param period Time in milliseconds between executions | |
60 | */ | |
61 | static synchronized void schedule(TimerTask task, long delay, long period) { | |
62 | 0 | if (null == _timer) { |
63 | // Force the new Timer thread to be created with a context class | |
64 | // loader set to the class loader that loaded this library | |
65 | 0 | ClassLoader ccl = (ClassLoader) AccessController.doPrivileged( |
66 | new PrivilegedGetTccl()); | |
67 | try { | |
68 | 0 | AccessController.doPrivileged(new PrivilegedSetTccl( |
69 | 0 | EvictionTimer.class.getClassLoader())); |
70 | 0 | _timer = new Timer(true); |
71 | 0 | } finally { |
72 | 0 | AccessController.doPrivileged(new PrivilegedSetTccl(ccl)); |
73 | 0 | } |
74 | } | |
75 | 0 | _usageCount++; |
76 | 0 | _timer.schedule(task, delay, period); |
77 | 0 | } |
78 | ||
79 | /** | |
80 | * Remove the specified eviction task from the timer. | |
81 | * @param task Task to be scheduled | |
82 | */ | |
83 | static synchronized void cancel(TimerTask task) { | |
84 | 0 | task.cancel(); |
85 | 0 | _usageCount--; |
86 | 0 | if (_usageCount == 0) { |
87 | 0 | _timer.cancel(); |
88 | 0 | _timer = null; |
89 | } | |
90 | 0 | } |
91 | ||
92 | /** | |
93 | * {@link PrivilegedAction} used to get the ContextClassLoader | |
94 | */ | |
95 | 0 | private static class PrivilegedGetTccl implements PrivilegedAction { |
96 | ||
97 | /** | |
98 | * {@inheritDoc} | |
99 | */ | |
100 | public Object run() { | |
101 | 0 | return Thread.currentThread().getContextClassLoader(); |
102 | } | |
103 | } | |
104 | ||
105 | /** | |
106 | * {@link PrivilegedAction} used to set the ContextClassLoader | |
107 | */ | |
108 | private static class PrivilegedSetTccl implements PrivilegedAction { | |
109 | ||
110 | /** ClassLoader */ | |
111 | private final ClassLoader cl; | |
112 | ||
113 | /** | |
114 | * Create a new PrivilegedSetTccl using the given classloader | |
115 | * @param cl ClassLoader to use | |
116 | */ | |
117 | 0 | PrivilegedSetTccl(ClassLoader cl) { |
118 | 0 | this.cl = cl; |
119 | 0 | } |
120 | ||
121 | /** | |
122 | * {@inheritDoc} | |
123 | */ | |
124 | public Object run() { | |
125 | 0 | Thread.currentThread().setContextClassLoader(cl); |
126 | 0 | return null; |
127 | } | |
128 | } | |
129 | ||
130 | } |