1 /*
2 * Copyright (c) 2013, 2015, 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 * @library /testlibrary
30 * @build jdk.test.lib.* AttachWithStalePidFileTarget
31 * @run main AttachWithStalePidFile
32 */
33
34 import jdk.test.lib.*;
35 import com.sun.tools.attach.VirtualMachine;
36 import sun.tools.attach.HotSpotVirtualMachine;
37 import java.lang.reflect.Field;
38 import java.nio.file.*;
39 import java.nio.file.attribute.*;
40 import java.io.*;
41
42 public class AttachWithStalePidFile {
43 public static void main(String... args) throws Exception {
44
45 // this test is only valid on non-Windows platforms
46 if(Platform.isWindows()) {
47 System.out.println("This test is only valid on non-Windows platforms.");
48 return;
49 }
50
51 // Since there might be stale pid-files owned by different
52 // users on the system we may need to retry the test in case we
53 // are unable to remove the existing file.
54 int retries = 5;
55 while(!runTest() && --retries > 0);
56
57 if(retries == 0) {
58 throw new RuntimeException("Test failed after 5 retries. " +
59 "Remove any /tmp/.java_pid* files and retry.");
60 }
61 }
62
63 public static boolean runTest() throws Exception {
64 ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
65 "-XX:+UnlockDiagnosticVMOptions", "-XX:+PauseAtStartup", "AttachWithStalePidFileTarget");
66 Process target = pb.start();
67 Path pidFile = null;
68
69 try {
70 int pid = getUnixProcessId(target);
71
72 // create the stale .java_pid file. use hard-coded /tmp path as in th VM
73 pidFile = createJavaPidFile(pid);
74 if(pidFile == null) {
75 return false;
76 }
77
78 // wait for vm.paused file to be created and delete it once we find it.
79 waitForAndResumeVM(pid);
80
81 waitForTargetReady(target);
82
83 HotSpotVirtualMachine vm = (HotSpotVirtualMachine)VirtualMachine.attach(((Integer)pid).toString());
84 BufferedReader remoteDataReader = new BufferedReader(new InputStreamReader(vm.remoteDataDump()));
85 String line = null;
86 while((line = remoteDataReader.readLine()) != null);
87
88 vm.detach();
89 return true;
90 }
91 finally {
92 target.destroy();
93 target.waitFor();
94
95 if(pidFile != null && Files.exists(pidFile)) {
96 Files.delete(pidFile);
97 }
98 }
99 }
100
101 private static void waitForTargetReady(Process target) throws IOException {
102 BufferedReader br = new BufferedReader(new InputStreamReader(target.getInputStream()));
103 String line = br.readLine();
104 // wait for the ready message having been printed or EOF (line == null)
105 while (line != null && !line.equals(AttachWithStalePidFileTarget.READY_MSG)) {
106 line = br.readLine();
107 }
108 // target VM ready
109 }
110
111 private static Path createJavaPidFile(int pid) throws Exception {
112 Path pidFile = Paths.get("/tmp/.java_pid" + pid);
113 if(Files.exists(pidFile)) {
114 try {
115 Files.delete(pidFile);
116 }
117 catch(FileSystemException e) {
118 if(e.getReason().matches("Operation not permitted|Not owner")) {
119 System.out.println("Unable to remove exisiting stale PID file" + pidFile);
120 System.out.println("===================================================");
121 e.printStackTrace(System.out);
122 return null;
123 }
124 throw e;
125 }
126 }
127 return Files.createFile(pidFile,
128 PosixFilePermissions.asFileAttribute(PosixFilePermissions.fromString("rw-------")));
129 }
130
131 private static void waitForAndResumeVM(int pid) throws Exception {
132 Path pauseFile = Paths.get("vm.paused." + pid);
133 int retries = 60;
134 while(!Files.exists(pauseFile) && --retries > 0) {
135 Thread.sleep(1000);
136 }
137 if(retries == 0) {
138 throw new RuntimeException("Timeout waiting for VM to start. " +
139 "vm.paused file not created within 60 seconds.");
140 }
141 Files.delete(pauseFile);
142 }
143
144 private static int getUnixProcessId(Process unixProcess) throws Exception {
145 Field pidField = unixProcess.getClass().getDeclaredField("pid");
146 pidField.setAccessible(true);
147 return (Integer)pidField.get(unixProcess);
148 }
149 }