1 /*
2 * Copyright (c) 2021, 2024, 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 * @modules jdk.jcmd
29 * @library /test/lib
30 * @run junit/othervm ThreadDumpToFileTest
31 */
32
33 import java.io.IOException;
34 import java.nio.file.Files;
35 import java.nio.file.Path;
36 import java.util.stream.Stream;
37 import jdk.test.lib.dcmd.PidJcmdExecutor;
38 import jdk.test.lib.process.OutputAnalyzer;
39 import jdk.test.lib.threaddump.ThreadDump;
40
41 import org.junit.jupiter.api.Test;
42 import static org.junit.jupiter.api.Assertions.*;
43
44 class ThreadDumpToFileTest {
45
46 /**
47 * Test thread dump, should be in plain text format.
48 */
49 @Test
50 void testThreadDump() throws IOException {
51 Path file = genThreadDumpPath(".txt");
52 testPlainThreadDump(file);
53 }
54
55 /**
56 * Test thread dump in plain text format.
57 */
58 @Test
59 void testPlainThreadDump() throws IOException {
60 Path file = genThreadDumpPath(".txt");
61 testPlainThreadDump(file, "-format=plain");
62 }
63
64 /**
65 * Test thread dump in JSON format.
66 */
67 @Test
68 void testJsonThreadDump() throws IOException {
69 Path file = genThreadDumpPath(".json");
70 jcmdThreadDumpToFile(file, "-format=json").shouldMatch("Created");
71
72 // parse the JSON text
73 String jsonText = Files.readString(file);
74 ThreadDump threadDump = ThreadDump.parse(jsonText);
75
76 // test that the process id is this process
77 assertTrue(threadDump.processId() == ProcessHandle.current().pid());
78
79 // test that the current thread is in the root thread container
80 var rootContainer = threadDump.rootThreadContainer();
81 var tid = Thread.currentThread().threadId();
82 rootContainer.findThread(tid).orElseThrow();
83 }
84
85 /**
86 * Test that an existing file is not overwritten.
87 */
88 @Test
89 void testDoNotOverwriteFile() throws IOException {
90 Path file = genThreadDumpPath(".txt");
91 Files.writeString(file, "xxx");
92
93 jcmdThreadDumpToFile(file, "").shouldMatch("exists");
94
95 // file should not be overridden
96 assertEquals("xxx", Files.readString(file));
97 }
98
99 /**
100 * Test overwriting an existing file.
101 */
102 @Test
103 void testOverwriteFile() throws IOException {
104 Path file = genThreadDumpPath(".txt");
105 Files.writeString(file, "xxx");
106 jcmdThreadDumpToFile(file, "-overwrite");
107 }
108
109 /**
110 * Test thread dump in plain text format.
111 */
112 private void testPlainThreadDump(Path file, String... options) throws IOException {
113 jcmdThreadDumpToFile(file, options).shouldMatch("Created");
114
115 // test that thread dump contains the name and id of the current thread
116 String name = Thread.currentThread().getName();
117 long tid = Thread.currentThread().threadId();
118 String expected = "#" + tid + " \"" + name + "\"";
119 assertTrue(find(file, expected), expected + " not found in " + file);
120 }
121
122 /**
123 * Generate a file path with the given suffix to use for the thread dump.
124 */
125 private Path genThreadDumpPath(String suffix) throws IOException {
126 Path dir = Path.of(".").toAbsolutePath();
127 Path file = Files.createTempFile(dir, "threads-", suffix);
128 Files.delete(file);
129 return file;
130 }
131
132 /**
133 * Launches jcmd Thread.dump_to_file to obtain a thread dump of this VM.
134 */
135 private OutputAnalyzer jcmdThreadDumpToFile(Path file, String... options) {
136 String cmd = "Thread.dump_to_file";
137 for (String option : options) {
138 cmd += " " + option;
139 }
140 return new PidJcmdExecutor().execute(cmd + " " + file);
141 }
142
143 /**
144 * Returns true if the given file contains a line with the string.
145 */
146 private boolean find(Path file, String text) throws IOException {
147 try (Stream<String> stream = Files.lines(file)) {
148 return stream.anyMatch(line -> line.indexOf(text) >= 0);
149 }
150 }
151 }