1 /*
2 * Copyright (c) 2018, 2020, 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 import static java.lang.Long.parseLong;
25 import static java.lang.System.getProperty;
26 import static java.nio.file.Files.readAllBytes;
27 import static java.util.Arrays.stream;
28 import static java.util.stream.Collectors.joining;
29 import static java.util.stream.Collectors.toList;
30 import static jdk.test.lib.process.ProcessTools.createJavaProcessBuilder;
31 import static jdk.test.lib.Platform.isWindows;
32 import jdk.test.lib.Utils;
33 import jtreg.SkippedException;
34
35 import java.io.BufferedReader;
36 import java.io.File;
37 import java.io.FileNotFoundException;
38 import java.io.FileOutputStream;
39 import java.io.IOException;
40 import java.io.InputStreamReader;
41 import java.util.Collection;
42 import java.util.Optional;
43 import java.util.stream.Stream;
44
45 /*
46 * @test TestInheritFD
47 * @bug 8176717 8176809 8222500
48 * @summary a new process should not inherit open file descriptors
49 * @comment On Aix lsof requires root privileges.
50 * @requires os.family != "aix"
51 * @library /test/lib
52 * @modules java.base/jdk.internal.misc
53 * java.management
54 * @run driver TestInheritFD
55 */
56
57 /**
58 * Test that HotSpot does not leak logging file descriptors.
59 *
60 * This test is performed in three steps. The first VM starts a second VM with
61 * gc logging enabled. The second VM starts a third VM and redirects the third
62 * VMs output to the first VM, it then exits and hopefully closes its log file.
63 *
64 * The third VM waits for the second to exit and close its log file. After that,
65 * the third VM tries to rename the log file of the second VM. If it succeeds in
66 * doing so it means that the third VM did not inherit the open log file
67 * (windows can not rename opened files easily)
68 *
69 * The third VM communicates the success to rename the file by printing "CLOSED
70 * FD". The first VM checks that the string was printed by the third VM.
71 *
72 * On unix like systems "lsof" is used.
73 */
74
75 public class TestInheritFD {
76
77 public static final String LEAKS_FD = "VM RESULT => LEAKS FD";
78 public static final String RETAINS_FD = "VM RESULT => RETAINS FD";
79 public static final String EXIT = "VM RESULT => VM EXIT";
80 public static final String LOG_SUFFIX = ".strangelogsuffixthatcanbecheckedfor";
81
82 // first VM
83 public static void main(String[] args) throws Exception {
84 String logPath = Utils.createTempFile("logging", LOG_SUFFIX).toFile().getName();
85 File commFile = Utils.createTempFile("communication", ".txt").toFile();
86
87 if (!isWindows() && !lsofCommand().isPresent()) {
88 throw new SkippedException("Could not find lsof like command");
89 }
90
91 ProcessBuilder pb = createJavaProcessBuilder(
92 "-Xlog:gc:\"" + logPath + "\"",
93 "-Dtest.jdk=" + getProperty("test.jdk"),
94 VMStartedWithLogging.class.getName(),
95 logPath);
96
97 pb.redirectOutput(commFile); // use temp file to communicate between processes
98 pb.start();
99
100 String out = "";
101 do {
102 out = new String(readAllBytes(commFile.toPath()));
103 Thread.sleep(100);
104 System.out.println("SLEEP 100 millis");
105 } while (!out.contains(EXIT));
106
107 System.out.println(out);
108 if (out.contains(RETAINS_FD)) {
109 System.out.println("Log file was not inherited by third VM");
110 } else {
111 throw new RuntimeException("could not match: " + RETAINS_FD);
112 }
113 }
114
115 static class VMStartedWithLogging {
116 // second VM
117 public static void main(String[] args) throws IOException, InterruptedException {
118 ProcessBuilder pb = createJavaProcessBuilder(
119 "-Dtest.jdk=" + getProperty("test.jdk"),
120 VMShouldNotInheritFileDescriptors.class.getName(),
121 args[0],
122 "" + ProcessHandle.current().pid());
123 pb.inheritIO(); // in future, redirect information from third VM to first VM
124 pb.start();
125
126 if (!isWindows()) {
127 System.out.println("(Second VM) Open file descriptors:\n" + outputContainingFilenames().stream().collect(joining("\n")));
128 }
129 }
130 }
131
132 static class VMShouldNotInheritFileDescriptors {
133 // third VM
134 public static void main(String[] args) throws InterruptedException {
135 try {
136 File logFile = new File(args[0]);
137 long parentPid = parseLong(args[1]);
138 fakeLeakyJVM(false); // for debugging of test case
139
140 if (isWindows()) {
141 windows(logFile, parentPid);
142 } else {
143 Collection<String> output = outputContainingFilenames();
144 System.out.println("(Third VM) Open file descriptors:\n" + output.stream().collect(joining("\n")));
145 System.out.println(findOpenLogFile(output) ? LEAKS_FD : RETAINS_FD);
146 }
147 } catch (Exception e) {
148 System.out.println(e.toString());
149 } finally {
150 System.out.println(EXIT);
151 }
152 }
153 }
154
155 // for debugging of test case
156 @SuppressWarnings("resource")
157 static void fakeLeakyJVM(boolean fake) {
158 if (fake) {
159 try {
160 new FileOutputStream("fakeLeakyJVM" + LOG_SUFFIX, false);
161 } catch (FileNotFoundException e) {
162 }
163 }
164 }
165
166 static Stream<String> run(String... args){
167 try {
168 return new BufferedReader(new InputStreamReader(new ProcessBuilder(args).start().getInputStream())).lines();
169 } catch (IOException e) {
170 throw new RuntimeException(e);
171 }
172 }
173
174 static Optional<String[]> lsofCommandCache = stream(new String[][]{
175 {"/usr/bin/lsof", "-p"},
176 {"/usr/sbin/lsof", "-p"},
177 {"/bin/lsof", "-p"},
178 {"/sbin/lsof", "-p"},
179 {"/usr/local/bin/lsof", "-p"}})
180 .filter(args -> new File(args[0]).exists())
181 .findFirst();
182
183 static Optional<String[]> lsofCommand() {
184 return lsofCommandCache;
185 }
186
187 static Collection<String> outputContainingFilenames() {
188 long pid = ProcessHandle.current().pid();
189
190 String[] command = lsofCommand().orElseThrow(() -> new RuntimeException("lsof like command not found"));
191 System.out.println("using command: " + command[0] + " " + command[1]);
192 return run(command[0], command[1], "" + pid).collect(toList());
193 }
194
195 static boolean findOpenLogFile(Collection<String> fileNames) {
196 return fileNames.stream()
197 .filter(fileName -> fileName.contains(LOG_SUFFIX))
198 .findAny()
199 .isPresent();
200 }
201
202 static void windows(File f, long parentPid) throws InterruptedException {
203 System.out.println("waiting for pid: " + parentPid);
204 ProcessHandle.of(parentPid).ifPresent(handle -> handle.onExit().join());
205 System.out.println("trying to rename file to the same name: " + f);
206 System.out.println(f.renameTo(f) ? RETAINS_FD : LEAKS_FD); // this parts communicates a closed file descriptor by printing "VM RESULT => RETAINS FD"
207 }
208 }
209