1 /*
2 * Copyright (c) 2021, 2025, 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 -Dminify=true ThreadDumpToFileTest
31 * @run junit/othervm -Dminify=false ThreadDumpToFileTest
32 */
33
34 import java.io.IOException;
35 import java.nio.file.Files;
36 import java.nio.file.Path;
37 import java.util.stream.Stream;
38 import jdk.test.lib.dcmd.PidJcmdExecutor;
39 import jdk.test.lib.process.OutputAnalyzer;
40 import jdk.test.lib.threaddump.ThreadDump;
41
42 import org.junit.jupiter.api.Test;
43 import org.junit.jupiter.api.BeforeAll;
44 import static org.junit.jupiter.api.Assertions.*;
45
46 class ThreadDumpToFileTest {
47 private static boolean minify;
48
49 @BeforeAll
50 static void setup() throws Exception {
51 minify = Boolean.getBoolean("minify");
52 }
53
54 /**
55 * Test thread dump, should be in plain text format.
56 */
57 @Test
58 void testThreadDump() throws IOException {
59 Path file = genThreadDumpPath(".txt");
60 testPlainThreadDump(file);
61 }
62
63 /**
64 * Test thread dump in plain text format.
65 */
66 @Test
67 void testPlainThreadDump() throws IOException {
68 Path file = genThreadDumpPath(".txt");
69 testPlainThreadDump(file, "-format=plain");
70 }
71
72 /**
73 * Test thread dump in JSON format.
74 */
75 @Test
76 void testJsonThreadDump() throws IOException {
77 Path file = genThreadDumpPath(".json");
78 jcmdThreadDumpToFile(file, "-format=json")
79 .shouldMatch("Created");
80
81 // parse the JSON text
82 String jsonText = Files.readString(file);
83 ThreadDump threadDump = ThreadDump.parse(jsonText);
84
85 // test that the process id is this process
86 assertTrue(threadDump.processId() == ProcessHandle.current().pid());
87
88 // test that the current thread is in the root thread container
89 var rootContainer = threadDump.rootThreadContainer();
90 var tid = Thread.currentThread().threadId();
91 rootContainer.findThread(tid).orElseThrow();
92 }
93
94 /**
95 * Test that an existing file is not overwritten.
96 */
97 @Test
98 void testDoNotOverwriteFile() throws IOException {
99 Path file = genThreadDumpPath(".txt");
100 Files.writeString(file, "xxx");
101
102 jcmdThreadDumpToFile(file, "")
103 .shouldMatch("exists");
104
105 // file should not be overridden
106 assertEquals("xxx", Files.readString(file));
107 }
108
109 /**
110 * Test overwriting an existing file.
111 */
112 @Test
113 void testOverwriteFile() throws IOException {
114 Path file = genThreadDumpPath(".txt");
115 Files.writeString(file, "xxx");
116 jcmdThreadDumpToFile(file, "-overwrite")
117 .shouldMatch("Created");
118 }
119
120 /**
121 * Test output file cannot be created.
122 */
123 @Test
124 void testFileCreateFails() throws IOException {
125 Path badFile = Path.of(".").toAbsolutePath()
126 .resolve("does-not-exist")
127 .resolve("does-not-exist")
128 .resolve("threads.bad");
129 jcmdThreadDumpToFile(badFile, "-format=plain")
130 .shouldMatch("Failed");
131 jcmdThreadDumpToFile(badFile, "-format=json")
132 .shouldMatch("Failed");
133 }
134
135 /**
136 * Test thread dump in plain text format.
137 */
138 private void testPlainThreadDump(Path file, String... options) throws IOException {
139 jcmdThreadDumpToFile(file, options).shouldMatch("Created");
140
141 // test that thread dump contains the name and id of the current thread
142 String name = Thread.currentThread().getName();
143 long tid = Thread.currentThread().threadId();
144 String expected = "#" + tid + " \"" + name + "\"";
145 assertTrue(find(file, expected), expected + " not found in " + file);
146 }
147
148 /**
149 * Generate a file path with the given suffix to use for the thread dump.
150 */
151 private Path genThreadDumpPath(String suffix) throws IOException {
152 Path dir = Path.of(".").toAbsolutePath();
153 Path file = Files.createTempFile(dir, "threads-", suffix);
154 Files.delete(file);
155 return file;
156 }
157
158 /**
159 * Launches jcmd Thread.dump_to_file to obtain a thread dump of this VM.
160 */
161 private OutputAnalyzer jcmdThreadDumpToFile(Path file, String... options) {
162 String cmd = "Thread.dump_to_file";
163 for (String option : options) {
164 cmd += " " + option;
165 }
166 if (minify) {
167 cmd += " -minify";
168 }
169 return new PidJcmdExecutor().execute(cmd + " " + file);
170 }
171
172 /**
173 * Returns true if the given file contains a line with the string.
174 */
175 private boolean find(Path file, String text) throws IOException {
176 try (Stream<String> stream = Files.lines(file)) {
177 return stream.anyMatch(line -> line.indexOf(text) >= 0);
178 }
179 }
180 }