1 /*
   2  * Copyright (c) 2016, 2019, 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 }