1 /*
2  * Copyright (C) 2008 The Guava Authors
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.google.common.testing;
18 
19 import static com.google.common.base.Preconditions.checkNotNull;
20 
21 import com.google.common.annotations.Beta;
22 import com.google.common.annotations.GwtCompatible;
23 import com.google.common.collect.Lists;
24 import com.google.errorprone.annotations.concurrent.GuardedBy;
25 import java.util.ArrayList;
26 import java.util.LinkedList;
27 import java.util.List;
28 import java.util.logging.Level;
29 import java.util.logging.Logger;
30 
31 /**
32  * A {@code TearDownStack} contains a stack of {@link TearDown} instances.
33  *
34  * <p>This class is thread-safe.
35  *
36  * @author Kevin Bourrillion
37  * @since 10.0
38  */
39 @Beta
40 @GwtCompatible
41 public class TearDownStack implements TearDownAccepter {
42   private static final Logger logger = Logger.getLogger(TearDownStack.class.getName());
43 
44   @GuardedBy("stack")
45   final LinkedList<TearDown> stack = new LinkedList<>();
46 
47   private final boolean suppressThrows;
48 
TearDownStack()49   public TearDownStack() {
50     this.suppressThrows = false;
51   }
52 
TearDownStack(boolean suppressThrows)53   public TearDownStack(boolean suppressThrows) {
54     this.suppressThrows = suppressThrows;
55   }
56 
57   @Override
addTearDown(TearDown tearDown)58   public final void addTearDown(TearDown tearDown) {
59     synchronized (stack) {
60       stack.addFirst(checkNotNull(tearDown));
61     }
62   }
63 
64   /** Causes teardown to execute. */
runTearDown()65   public final void runTearDown() {
66     List<Throwable> exceptions = new ArrayList<>();
67     List<TearDown> stackCopy;
68     synchronized (stack) {
69       stackCopy = Lists.newArrayList(stack);
70       stack.clear();
71     }
72     for (TearDown tearDown : stackCopy) {
73       try {
74         tearDown.tearDown();
75       } catch (Throwable t) {
76         if (suppressThrows) {
77           logger.log(Level.INFO, "exception thrown during tearDown", t);
78         } else {
79           exceptions.add(t);
80         }
81       }
82     }
83     if (!suppressThrows && (exceptions.size() > 0)) {
84       throw ClusterException.create(exceptions);
85     }
86   }
87 }
88