AttachWithStalePidFile.java revision 4977:2e8f19c2feef 
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 * @compile AttachWithStalePidFileTarget.java
31 * @run main AttachWithStalePidFile
32 */
33
34import com.oracle.java.testlibrary.*;
35import com.sun.tools.attach.VirtualMachine;
36import sun.tools.attach.HotSpotVirtualMachine;
37import java.lang.reflect.Field;
38import java.nio.file.*;
39import java.nio.file.attribute.*;
40import java.io.*;
41
42public 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}
140