1/*
2 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25package java.io;
26
27import java.util.*;
28import java.io.File;
29
30/**
31 * This class holds a set of filenames to be deleted on VM exit through a shutdown hook.
32 * A set is used both to prevent double-insertion of the same file as well as offer
33 * quick removal.
34 */
35
36class DeleteOnExitHook {
37    private static LinkedHashSet<String> files = new LinkedHashSet<>();
38    static {
39        // BEGIN Android-changed: Use Runtime.addShutdownHook() rather than SharedSecrets.
40        Runtime.getRuntime().addShutdownHook(new Thread() {
41            public void run() {
42                runHooks();
43            }
44        });
45        // END Android-changed: Use Runtime.addShutdownHook() rather than SharedSecrets.
46    }
47
48    private DeleteOnExitHook() {}
49
50    static synchronized void add(String file) {
51        if(files == null) {
52            // DeleteOnExitHook is running. Too late to add a file
53            throw new IllegalStateException("Shutdown in progress");
54        }
55
56        files.add(file);
57    }
58
59    static void runHooks() {
60        LinkedHashSet<String> theFiles;
61
62        synchronized (DeleteOnExitHook.class) {
63            theFiles = files;
64            files = null;
65        }
66
67        ArrayList<String> toBeDeleted = new ArrayList<>(theFiles);
68
69        // reverse the list to maintain previous jdk deletion order.
70        // Last in first deleted.
71        Collections.reverse(toBeDeleted);
72        for (String filename : toBeDeleted) {
73            (new File(filename)).delete();
74        }
75    }
76}
77