1 /*

     2  * Copyright (c) 2016, 2018, 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.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package jdk.jfr.internal;

    27 

    28 import java.io.IOException;

    29 import java.nio.file.Paths;

    30 import java.security.AccessControlContext;

    31 import java.security.AccessController;

    32 import java.security.PrivilegedActionException;

    33 import java.security.PrivilegedExceptionAction;

    34 import java.time.LocalDateTime;

    35 

    36 import jdk.jfr.RecordingState;

    37 

    38 /**

    39  * Class responsible for dumping recordings on exit

    40  *

    41  */

    42 final class ShutdownHook implements Runnable {

    43     private final PlatformRecorder recorder;

    44     Object tlabDummyObject;

    45 

    46     ShutdownHook(PlatformRecorder recorder) {

    47         this.recorder = recorder;

    48     }

    49 

    50     @Override

    51     public void run() {

    52         // this allocation is done in order to fetch a new TLAB before

    53         // starting any "real" operations. In low memory situations,

    54         // we would like to take an OOM as early as possible.

    55         tlabDummyObject = new Object();

    56 

    57         for (PlatformRecording recording : recorder.getRecordings()) {

    58             if (recording.getDumpOnExit() && recording.getState() == RecordingState.RUNNING) {

    59                 dump(recording);

    60             }

    61         }

    62         recorder.destroy();

    63     }

    64 

    65     private void dump(PlatformRecording recording) {

    66         try {

    67             WriteableUserPath dest = recording.getDestination();

    68             if (dest == null) {

    69                 dest = makeDumpOnExitPath(recording);

    70             }

    71             if (dest != null) {

    72                 recording.stop("Dump on exit", dest);

    73             }

    74         } catch (Exception e) {

    75             Logger.log(LogTag.JFR, LogLevel.DEBUG, () -> "Could not dump recording " + recording.getName() + " on exit.");

    76         }

    77     }

    78 

    79     private WriteableUserPath makeDumpOnExitPath(PlatformRecording recording) {

    80         try {

    81             String pid = JVM.getJVM().getPid();

    82             String dfText = Repository.REPO_DATE_FORMAT.format(LocalDateTime.now());

    83             String name = "hotspot-" + "pid-" + pid + "-id-" + recording.getId() + "-" + dfText + ".jfr";

    84             AccessControlContext acc = recording.getNoDestinationDumpOnExitAccessControlContext();

    85             return AccessController.doPrivileged(new PrivilegedExceptionAction<WriteableUserPath>() {

    86                 @Override

    87                 public WriteableUserPath run() throws Exception {

    88                     return new WriteableUserPath(Paths.get(".", name));

    89                 }

    90             }, acc);

    91         } catch (PrivilegedActionException e) {

    92             Throwable t = e.getCause();

    93             if (t instanceof SecurityException) {

    94                 Logger.log(LogTag.JFR, LogLevel.WARN, "Not allowed to create dump path for recording " + recording.getId() + " on exit. " + e.getMessage());

    95             }

    96             if (t instanceof IOException) {

    97                 Logger.log(LogTag.JFR, LogLevel.WARN, "Could not dump " + recording.getId() + " on exit. " + e.getMessage());

    98             }

    99             return null;

   100         }

   101     }

   102 

   103     static final class ExceptionHandler implements Thread.UncaughtExceptionHandler {

   104         public void uncaughtException(Thread t, Throwable e) {

   105             JVM.getJVM().uncaughtException(t, e);

   106         }

   107     }

   108 }