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
|
/*
* Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/* @test
* @bug 8029516
* @summary Bash on WatchKey.cancel with a view to causing a crash when
* an outstanding I/O operation on directory completes after the
* directory has been closed
*/
import java.nio.file.ClosedWatchServiceException;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import static java.nio.file.StandardWatchEventKinds.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
public class LotsOfCancels {
// set to true for any exceptions
static volatile boolean failed;
public static void main(String[] args) throws Exception {
// create a bunch of directories. Create two tasks for each directory,
// one to bash on cancel, the other to poll the events
ExecutorService pool = Executors.newCachedThreadPool();
try {
Path testDir = Paths.get(System.getProperty("test.dir", "."));
Path top = Files.createTempDirectory(testDir, "LotsOfCancels");
for (int i=1; i<=16; i++) {
int id = i;
Path dir = Files.createDirectory(top.resolve("dir-" + i));
WatchService watcher = FileSystems.getDefault().newWatchService();
pool.submit(() -> handle(id, dir, watcher));
pool.submit(() -> poll(id, watcher));
}
} finally {
pool.shutdown();
}
// give thread pool lots of time to terminate
if (!pool.awaitTermination(5L, TimeUnit.MINUTES))
throw new RuntimeException("Thread pool did not terminate");
if (failed)
throw new RuntimeException("Test failed, see log for details");
}
/**
* Stress the given WatchService, specifically the cancel method, in
* the given directory. Closes the WatchService when done.
*/
static void handle(int id, Path dir, WatchService watcher) {
System.out.printf("begin handle %d%n", id);
try {
try {
Path file = dir.resolve("anyfile");
for (int i=0; i<2000; i++) {
WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE);
Files.createFile(file);
Files.delete(file);
key.cancel();
}
} finally {
System.out.printf("WatchService %d closing ...%n", id);
watcher.close();
System.out.printf("WatchService %d closed %n", id);
}
} catch (Exception e) {
e.printStackTrace();
failed = true;
}
System.out.printf("end handle %d%n", id);
}
/**
* Polls the given WatchService in a tight loop. This keeps the event
* queue drained, it also hogs a CPU core which seems necessary to
* tickle the original bug.
*/
static void poll(int id, WatchService watcher) {
System.out.printf("begin poll %d%n", id);
try {
for (;;) {
WatchKey key = watcher.take();
if (key != null) {
key.pollEvents();
key.reset();
}
}
} catch (ClosedWatchServiceException expected) {
// nothing to do but print
System.out.printf("poll %d expected exception %s%n", id, expected);
} catch (Exception e) {
e.printStackTrace();
failed = true;
}
System.out.printf("end poll %d%n", id);
}
}
|
