1 /*
2 * Copyright (c) 2021, 2023, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 /*
25 * @test
26 * @bug 8284161 8287008
27 * @summary Basic test for jcmd Thread.dump_to_file
28 * @library /test/lib
29 * @run junit/othervm ThreadDumpToFileTest
30 */
31
32 import java.io.IOException;
33 import java.nio.file.Files;
34 import java.nio.file.Path;
35 import java.util.stream.Stream;
36 import jdk.test.lib.dcmd.PidJcmdExecutor;
37 import jdk.test.lib.process.OutputAnalyzer;
38 import jdk.test.lib.threaddump.ThreadDump;
39
40 import org.junit.jupiter.api.Test;
41 import static org.junit.jupiter.api.Assertions.*;
42
43 class ThreadDumpToFileTest {
44
45 /**
46 * Test thread dump, should be in plain text format.
47 */
48 @Test
49 void testThreadDump() throws IOException {
50 Path file = genThreadDumpPath(".txt");
51 testPlainThreadDump(file);
52 }
53
54 /**
55 * Test thread dump in plain text format.
56 */
57 @Test
58 void testPlainThreadDump() throws IOException {
59 Path file = genThreadDumpPath(".txt");
60 testPlainThreadDump(file, "-format=plain");
61 }
62
63 /**
64 * Test thread dump in JSON format.
65 */
66 @Test
67 void testJsonThreadDump() throws IOException {
68 Path file = genThreadDumpPath(".json");
69 jcmdThreadDumpToFile(file, "-format=json").shouldMatch("Created");
70
71 // parse the JSON text
72 String jsonText = Files.readString(file);
73 ThreadDump threadDump = ThreadDump.parse(jsonText);
74
75 // test that the process id is this process
76 assertTrue(threadDump.processId() == ProcessHandle.current().pid());
77
78 // test that the current thread is in the root thread container
79 var rootContainer = threadDump.rootThreadContainer();
80 var tid = Thread.currentThread().threadId();
81 rootContainer.findThread(tid).orElseThrow();
82 }
83
84 /**
85 * Test that an existing file is not overwritten.
86 */
87 @Test
88 void testDoNotOverwriteFile() throws IOException {
89 Path file = genThreadDumpPath(".txt");
90 Files.writeString(file, "xxx");
91
92 jcmdThreadDumpToFile(file, "").shouldMatch("exists");
93
94 // file should not be overridden
95 assertEquals("xxx", Files.readString(file));
96 }
97
98 /**
99 * Test overwriting an existing file.
100 */
101 @Test
102 void testOverwriteFile() throws IOException {
103 Path file = genThreadDumpPath(".txt");
104 Files.writeString(file, "xxx");
105 jcmdThreadDumpToFile(file, "-overwrite");
106 }
107
108 /**
109 * Test thread dump in plain text format.
110 */
111 private void testPlainThreadDump(Path file, String... options) throws IOException {
112 jcmdThreadDumpToFile(file, options).shouldMatch("Created");
113
114 // test that thread dump contains the name and id of the current thread
115 String name = Thread.currentThread().getName();
116 long tid = Thread.currentThread().threadId();
117 String expected = "#" + tid + " \"" + name + "\"";
118 assertTrue(find(file, expected), expected + " not found in " + file);
119 }
120
121 /**
122 * Generate a file path with the given suffix to use for the thread dump.
123 */
124 private Path genThreadDumpPath(String suffix) throws IOException {
125 Path dir = Path.of(".").toAbsolutePath();
126 Path file = Files.createTempFile(dir, "threads-", suffix);
127 Files.delete(file);
128 return file;
129 }
130
131 /**
132 * Launches jcmd Thread.dump_to_file to obtain a thread dump of this VM.
133 */
134 private OutputAnalyzer jcmdThreadDumpToFile(Path file, String... options) {
135 String cmd = "Thread.dump_to_file";
136 for (String option : options) {
137 cmd += " " + option;
138 }
139 return new PidJcmdExecutor().execute(cmd + " " + file);
140 }
141
142 /**
143 * Returns true if the given file contains a line with the string.
144 */
145 private boolean find(Path file, String text) throws IOException {
146 try (Stream<String> stream = Files.lines(file)) {
147 return stream.anyMatch(line -> line.indexOf(text) >= 0);
148 }
149 }
150 }