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
|
/*
* Copyright (c) 2017 Cisco and/or its affiliates.
*
* Licensed 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 io.fd.honeycomb.impl;
import com.google.common.annotations.VisibleForTesting;
import io.fd.honeycomb.data.init.ShutdownHandler;
import java.util.Deque;
import java.util.LinkedList;
import javax.annotation.Nonnull;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public final class ShutdownHandlerImpl implements ShutdownHandler {
private static final Logger LOG = LoggerFactory.getLogger(ShutdownHandlerImpl.class);
private final Deque<CloseableComponent> components;
public ShutdownHandlerImpl() {
components = new LinkedList<>();
Runtime.getRuntime().addShutdownHook(new Thread((this::performShutdown)));
}
@Override
public synchronized void register(@Nonnull final String name, @Nonnull final AutoCloseable component) {
LOG.debug("Registering component {} for proper shutdown", name);
components.add(new CloseableComponent(name, component));
LOG.trace("Component {} properly register", name);
}
private static final class CloseableComponent {
private final String name;
private final AutoCloseable component;
private CloseableComponent(final String name, final AutoCloseable component) {
this.name = name;
this.component = component;
}
private String getName() {
return name;
}
private AutoCloseable getComponent() {
return component;
}
}
@VisibleForTesting
void performShutdown() {
// close components in reverse order that they were registered
components.descendingIterator().forEachRemaining(closeable -> {
LOG.info("Closing component {}", closeable.getName());
try {
closeable.getComponent().close();
} catch (Exception e) {
// We can't do much here, so logging exception and moving to the next closable component
LOG.warn("Unable to close component {}", closeable.getName(), e);
}
});
}
}
|