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 

    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 }