1 /*
   2  * Copyright (c) 2012, 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 package sun.hotspot;
  26 import java.security.BasicPermission;
  27 import sun.hotspot.parser.DiagnosticCommand;
  28 
  29 public class WhiteBox {
  30 
  31   @SuppressWarnings("serial")
  32   public static class WhiteBoxPermission extends BasicPermission {
  33     public WhiteBoxPermission(String s) {
  34       super(s);
  35     }
  36   }
  37 
  38   private WhiteBox() {}
  39   private static final WhiteBox instance = new WhiteBox();
  40   private static native void registerNatives();
  41 
  42   /**
  43    * Returns the singleton WhiteBox instance.
  44    *
  45    * The returned WhiteBox object should be carefully guarded
  46    * by the caller, since it can be used to read and write data
  47    * at arbitrary memory addresses. It must never be passed to
  48    * untrusted code.
  49    */
  50   public synchronized static WhiteBox getWhiteBox() {
  51     SecurityManager sm = System.getSecurityManager();
  52     if (sm != null) {
  53       sm.checkPermission(new WhiteBoxPermission("getInstance"));
  54     }
  55     return instance;
  56   }
  57 
  58   static {
  59     registerNatives();
  60   }
  61 
  62   // Memory
  63   public native long getObjectAddress(Object o);
  64   public native int  getHeapOopSize();
  65 
  66   // Runtime
  67   // Make sure class name is in the correct format
  68   public boolean isClassAlive(String name) {
  69     return isClassAlive0(name.replace('.', '/'));
  70   }
  71   private native boolean isClassAlive0(String name);
  72 
  73   // G1
  74   public native boolean g1InConcurrentMark();
  75   public native boolean g1IsHumongous(Object o);
  76   public native long    g1NumFreeRegions();
  77   public native int     g1RegionSize();
  78   public native Object[]    parseCommandLine(String commandline, DiagnosticCommand[] args);
  79   
  80   // NMT
  81   public native boolean NMTAllocTest();
  82   public native boolean NMTFreeTestMemory();
  83   public native boolean NMTWaitForDataMerge();
  84 }