-
Notifications
You must be signed in to change notification settings - Fork 3.3k
/
TestConfigurationManager.java
143 lines (122 loc) · 4.75 KB
/
TestConfigurationManager.java
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
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.conf;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseClassTestRule;
import org.apache.hadoop.hbase.testclassification.ClientTests;
import org.apache.hadoop.hbase.testclassification.SmallTests;
import org.junit.ClassRule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@Category({SmallTests.class, ClientTests.class})
public class TestConfigurationManager {
@ClassRule
public static final HBaseClassTestRule CLASS_RULE =
HBaseClassTestRule.forClass(TestConfigurationManager.class);
private static final Logger LOG = LoggerFactory.getLogger(TestConfigurationManager.class);
static class DummyConfigurationObserver implements ConfigurationObserver {
private boolean notifiedOnChange = false;
private final ConfigurationManager cm;
public DummyConfigurationObserver(ConfigurationManager cm) {
this.cm = cm;
register();
}
@Override
public void onConfigurationChange(Configuration conf) {
notifiedOnChange = true;
}
// Was the observer notified on Configuration change?
public boolean wasNotifiedOnChange() {
return notifiedOnChange;
}
public void resetNotifiedOnChange() {
notifiedOnChange = false;
}
public void register() {
cm.registerObserver(this);
}
public void deregister() {
cm.deregisterObserver(this);
}
}
/**
* Test if observers get notified by the <code>ConfigurationManager</code>
* when the Configuration is reloaded.
*/
@Test
public void testCheckIfObserversNotified() {
Configuration conf = new Configuration();
ConfigurationManager cm = new ConfigurationManager();
DummyConfigurationObserver d1 = new DummyConfigurationObserver(cm);
// Check if we get notified.
cm.notifyAllObservers(conf);
assertTrue(d1.wasNotifiedOnChange());
d1.resetNotifiedOnChange();
// Now check if we get notified on change with more than one observers.
DummyConfigurationObserver d2 = new DummyConfigurationObserver(cm);
cm.notifyAllObservers(conf);
assertTrue(d1.wasNotifiedOnChange());
d1.resetNotifiedOnChange();
assertTrue(d2.wasNotifiedOnChange());
d2.resetNotifiedOnChange();
// Now try deregistering an observer and verify that it was not notified
d2.deregister();
cm.notifyAllObservers(conf);
assertTrue(d1.wasNotifiedOnChange());
d1.resetNotifiedOnChange();
assertFalse(d2.wasNotifiedOnChange());
}
// Register an observer that will go out of scope immediately, allowing
// us to test that out of scope observers are deregistered.
private void registerLocalObserver(ConfigurationManager cm) {
new DummyConfigurationObserver(cm);
}
/**
* Test if out-of-scope observers are deregistered on GC.
*/
@Test
public void testDeregisterOnOutOfScope() {
Configuration conf = new Configuration();
ConfigurationManager cm = new ConfigurationManager();
boolean outOfScopeObserversDeregistered = false;
// On my machine, I was able to cause a GC after around 5 iterations.
// If we do not cause a GC in 100k iterations, which is very unlikely,
// there might be something wrong with the GC.
for (int i = 0; i < 100000; i++) {
registerLocalObserver(cm);
cm.notifyAllObservers(conf);
// 'Suggest' the system to do a GC. We should be able to cause GC
// atleast once in the 2000 iterations.
System.gc();
// If GC indeed happened, all the observers (which are all out of scope),
// should have been deregistered.
if (cm.getNumObservers() <= i) {
outOfScopeObserversDeregistered = true;
break;
}
}
if (!outOfScopeObserversDeregistered) {
LOG.warn("Observers were not GC-ed! Something seems to be wrong.");
}
assertTrue(outOfScopeObserversDeregistered);
}
}