1 import static java.io.File.createTempFile;
2 import static java.lang.Long.parseLong;
3 import static java.lang.System.getProperty;
4 import static java.nio.file.Files.readAllBytes;
5 import static java.util.Arrays.stream;
6 import static java.util.stream.Collectors.joining;
7 import static java.util.stream.Collectors.toList;
8 import static jdk.test.lib.process.ProcessTools.createJavaProcessBuilder;
9
10 import java.io.BufferedReader;
11 import java.io.File;
12 import java.io.FileNotFoundException;
13 import java.io.FileOutputStream;
14 import java.io.IOException;
15 import java.io.InputStreamReader;
16 import java.util.Collection;
17 import java.util.stream.Stream;
18
19 /*
20 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
21 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
22 *
23 * This code is free software; you can redistribute it and/or modify it
24 * under the terms of the GNU General Public License version 2 only, as
25 * published by the Free Software Foundation.
26 *
27 * This code is distributed in the hope that it will be useful, but WITHOUT
28 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
29 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
30 * version 2 for more details (a copy is included in the LICENSE file that
31 * accompanied this code).
32 *
33 * You should have received a copy of the GNU General Public License version
34 * 2 along with this work; if not, write to the Free Software Foundation,
35 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
36 *
37 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
38 * or visit www.oracle.com if you need additional information or have any
39 * questions.
40 */
41
42 /*
43 * @test TestInheritFD
44 * @bug 8176717 8176809
45 * @summary a new process should not inherit open file descriptors
46 * @library /test/lib
47 * @modules java.base/jdk.internal.misc
48 * java.management
49 */
50
51 /**
52 * Test that HotSpot does not leak logging file descriptors.
53 *
54 * This test is performed in three steps. The first VM starts a second VM with
55 * gc logging enabled. The second VM starts a third VM and redirects the third
56 * VMs output to the first VM, it then exits and hopefully closes its log file.
57 *
58 * The third VM waits for the second to exit and close its log file. After that,
59 * the third VM tries to rename the log file of the second VM. If it succeeds in
60 * doing so it means that the third VM did not inherit the open log file
61 * (windows can not rename opened files easily)
62 *
63 * The third VM communicates the success to rename the file by printing "CLOSED
64 * FD". The first VM checks that the string was printed by the third VM.
65 *
66 * On unix like systems "lsof" or "pfiles" is used.
67 */
68
69 public class TestInheritFD {
70
71 public static final String LEAKS_FD = "VM RESULT => LEAKS FD";
72 public static final String RETAINS_FD = "VM RESULT => RETAINS FD";
73 public static final String EXIT = "VM RESULT => VM EXIT";
74 public static final String LOG_SUFFIX = ".strangelogsuffixthatcanbecheckedfor";
75
76 // first VM
77 public static void main(String[] args) throws Exception {
78 String logPath = createTempFile("logging", LOG_SUFFIX).getName();
79 File commFile = createTempFile("communication", ".txt");
80
81 ProcessBuilder pb = createJavaProcessBuilder(
82 "-Xlog:gc:\"" + logPath + "\"",
83 "-Dtest.jdk=" + getProperty("test.jdk"),
84 VMStartedWithLogging.class.getName(),
85 logPath);
86
87 pb.redirectOutput(commFile); // use temp file to communicate between processes
88 pb.start();
89
90 String out = "";
91 do {
92 out = new String(readAllBytes(commFile.toPath()));
93 Thread.sleep(100);
94 System.out.println("SLEEP 100 millis");
95 } while (!out.contains(EXIT));
96
97 System.out.println(out);
98 if (out.contains(RETAINS_FD)) {
99 System.out.println("Log file was not inherited by third VM");
100 } else {
101 throw new RuntimeException("could not match: " + RETAINS_FD);
102 }
103 }
104
105 static class VMStartedWithLogging {
106 // second VM
107 public static void main(String[] args) throws IOException, InterruptedException {
108 ProcessBuilder pb = createJavaProcessBuilder(
109 "-Dtest.jdk=" + getProperty("test.jdk"),
110 VMShouldNotInheritFileDescriptors.class.getName(),
111 args[0],
112 "" + ProcessHandle.current().pid());
113 pb.inheritIO(); // in future, redirect information from third VM to first VM
114 pb.start();
115
116 if (getProperty("os.name").toLowerCase().contains("win") == false) {
117 System.out.println("(Second VM) Open file descriptors:\n" + outputContainingFilenames().stream().collect(joining("\n")));
118 }
119 }
120 }
121
122 static class VMShouldNotInheritFileDescriptors {
123 // third VM
124 public static void main(String[] args) throws InterruptedException {
125 try {
126 File logFile = new File(args[0]);
127 long parentPid = parseLong(args[1]);
128 fakeLeakyJVM(false); // for debugging of test case
129
130 if (getProperty("os.name").toLowerCase().contains("win")) {
131 windows(logFile, parentPid);
132 } else {
133 Collection<String> output = outputContainingFilenames();
134 System.out.println("(Third VM) Open file descriptors:\n" + output.stream().collect(joining("\n")));
135 System.out.println(findOpenLogFile(output) ? LEAKS_FD : RETAINS_FD);
136 }
137 } catch (Exception e) {
138 System.out.println(e.toString());
139 } finally {
140 System.out.println(EXIT);
141 }
142 }
143 }
144
145 // for debugging of test case
146 @SuppressWarnings("resource")
147 static void fakeLeakyJVM(boolean fake) {
148 if (fake) {
149 try {
150 new FileOutputStream("fakeLeakyJVM" + LOG_SUFFIX, false);
151 } catch (FileNotFoundException e) {
152 }
153 }
154 }
155
156 static Stream<String> run(String... args){
157 try {
158 return new BufferedReader(new InputStreamReader(new ProcessBuilder(args).start().getInputStream())).lines();
159 } catch (IOException e) {
160 throw new RuntimeException(e);
161 }
162 }
163
164 static Collection<String> outputContainingFilenames() {
165 long pid = ProcessHandle.current().pid();
166 String[] command = stream(new String[][]{
167 {"/usr/bin/lsof", "-p"},
168 {"/usr/sbin/lsof", "-p"},
169 {"/bin/lsof", "-p"},
170 {"/sbin/lsof", "-p"},
171 {"/usr/bin/pfiles", "-F"}}) // Solaris
172 .filter(args -> new File(args[0]).exists())
173 .findFirst()
174 .orElseThrow(() -> new RuntimeException("could not find lsof-like command"));
175
176 System.out.println("using command: " + command[0] + " " + command[1]);
177 return run(command[0], command[1], "" + pid).collect(toList());
178 }
179
180 static boolean findOpenLogFile(Collection<String> fileNames) {
181 return fileNames.stream()
182 .filter(fileName -> fileName.contains(LOG_SUFFIX))
183 .findAny()
184 .isPresent();
185 }
186
187 static void windows(File f, long parentPid) throws InterruptedException {
188 System.out.println("waiting for pid: " + parentPid);
189 ProcessHandle.of(parentPid).ifPresent(handle -> handle.onExit().join());
190 System.out.println("trying to rename file to the same name: " + f);
191 System.out.println(f.renameTo(f) ? RETAINS_FD : LEAKS_FD); // this parts communicates a closed file descriptor by printing "VM RESULT => RETAINS FD"
192 }