1 /*
2 * Copyright (c) 2013, 2016, 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 7162400
27 * @key regression
28 * @summary Regression test for attach issue where stale pid files in /tmp lead to connection issues
29 * @modules java.base/jdk.internal.misc
30 * @modules jdk.attach/sun.tools.attach
31 * @library /testlibrary
32 * @build jdk.test.lib.* AttachWithStalePidFileTarget
33 * @run main AttachWithStalePidFile
34 */
35
36 import jdk.test.lib.*;
37 import com.sun.tools.attach.VirtualMachine;
38 import sun.tools.attach.HotSpotVirtualMachine;
39 import java.lang.reflect.Field;
40 import java.nio.file.*;
41 import java.nio.file.attribute.*;
42 import java.io.*;
43
44 public class AttachWithStalePidFile {
45 public static void main(String... args) throws Exception {
46
47 // this test is only valid on non-Windows platforms
48 if(Platform.isWindows()) {
49 System.out.println("This test is only valid on non-Windows platforms.");
50 return;
51 }
52
53 // Since there might be stale pid-files owned by different
54 // users on the system we may need to retry the test in case we
55 // are unable to remove the existing file.
56 int retries = 5;
57 while(!runTest() && --retries > 0);
58
59 if(retries == 0) {
60 throw new RuntimeException("Test failed after 5 retries. " +
61 "Remove any /tmp/.java_pid* files and retry.");
62 }
63 }
64
65 public static boolean runTest() throws Exception {
66 ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
67 "-XX:+UnlockDiagnosticVMOptions", "-XX:+PauseAtStartup", "AttachWithStalePidFileTarget");
68 Process target = pb.start();
69 Path pidFile = null;
70
71 try {
72 int pid = getUnixProcessId(target);
73
74 // create the stale .java_pid file. use hard-coded /tmp path as in th VM
75 pidFile = createJavaPidFile(pid);
76 if(pidFile == null) {
77 return false;
78 }
79
80 // wait for vm.paused file to be created and delete it once we find it.
81 waitForAndResumeVM(pid);
82
83 waitForTargetReady(target);
84
85 HotSpotVirtualMachine vm = (HotSpotVirtualMachine)VirtualMachine.attach(((Integer)pid).toString());
86 BufferedReader remoteDataReader = new BufferedReader(new InputStreamReader(vm.remoteDataDump()));
87 String line = null;
88 while((line = remoteDataReader.readLine()) != null);
89
90 vm.detach();
91 return true;
92 }
93 finally {
94 target.destroy();
95 target.waitFor();
96
97 if(pidFile != null && Files.exists(pidFile)) {
98 Files.delete(pidFile);
99 }
100 }
101 }
102
103 private static void waitForTargetReady(Process target) throws IOException {
104 BufferedReader br = new BufferedReader(new InputStreamReader(target.getInputStream()));
105 String line = br.readLine();
106 // wait for the ready message having been printed or EOF (line == null)
107 while (line != null && !line.equals(AttachWithStalePidFileTarget.READY_MSG)) {
108 line = br.readLine();
109 }
110 // target VM ready
111 }
112
113 private static Path createJavaPidFile(int pid) throws Exception {
114 Path pidFile = Paths.get("/tmp/.java_pid" + pid);
115 if(Files.exists(pidFile)) {
116 try {
117 Files.delete(pidFile);
118 }
119 catch(FileSystemException e) {
120 if(e.getReason().matches("Operation not permitted|Not owner")) {
121 System.out.println("Unable to remove exisiting stale PID file" + pidFile);
122 System.out.println("===================================================");
123 e.printStackTrace(System.out);
124 return null;
125 }
126 throw e;
127 }
128 }
129 return Files.createFile(pidFile,
130 PosixFilePermissions.asFileAttribute(PosixFilePermissions.fromString("rw-------")));
131 }
132
133 private static void waitForAndResumeVM(int pid) throws Exception {
134 Path pauseFile = Paths.get("vm.paused." + pid);
135 int retries = 60;
136 while(!Files.exists(pauseFile) && --retries > 0) {
137 Thread.sleep(1000);
138 }
139 if(retries == 0) {
140 throw new RuntimeException("Timeout waiting for VM to start. " +
141 "vm.paused file not created within 60 seconds.");
142 }
143 Files.delete(pauseFile);
144 }
145
146 private static int getUnixProcessId(Process unixProcess) throws Exception {
147 Field pidField = unixProcess.getClass().getDeclaredField("pid");
148 pidField.setAccessible(true);
149 return (Integer)pidField.get(unixProcess);
150 }
151 }