1 /*
2 * Copyright (c) 2013, 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 com.oracle.java.testlibrary.* AttachWithStalePidFileTarget
31 * @run main AttachWithStalePidFile
32 */
33
34 import com.oracle.java.testlibrary.*;
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 // unfortunately there's no reliable way to know the VM is ready to receive the
82 // attach request so we have to do an arbitrary sleep.
83 Thread.sleep(5000);
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 Path createJavaPidFile(int pid) throws Exception {
104 Path pidFile = Paths.get("/tmp/.java_pid" + pid);
105 if(Files.exists(pidFile)) {
106 try {
107 Files.delete(pidFile);
108 }
109 catch(FileSystemException e) {
110 if(e.getReason().equals("Operation not permitted")) {
111 System.out.println("Unable to remove exisiting stale PID file" + pidFile);
112 return null;
113 }
114 throw e;
115 }
116 }
117 return Files.createFile(pidFile,
118 PosixFilePermissions.asFileAttribute(PosixFilePermissions.fromString("rw-------")));
119 }
120
121 private static void waitForAndResumeVM(int pid) throws Exception {
122 Path pauseFile = Paths.get("vm.paused." + pid);
123 int retries = 60;
124 while(!Files.exists(pauseFile) && --retries > 0) {
125 Thread.sleep(1000);
126 }
127 if(retries == 0) {
128 throw new RuntimeException("Timeout waiting for VM to start. " +
129 "vm.paused file not created within 60 seconds.");
130 }
131 Files.delete(pauseFile);
132 }
133
134 private static int getUnixProcessId(Process unixProcess) throws Exception {
135 Field pidField = unixProcess.getClass().getDeclaredField("pid");
136 pidField.setAccessible(true);
137 return (Integer)pidField.get(unixProcess);
138 }
139 }