44   /**
  45    * Returns the singleton WhiteBox instance.
  46    *
  47    * The returned WhiteBox object should be carefully guarded
  48    * by the caller, since it can be used to read and write data
  49    * at arbitrary memory addresses. It must never be passed to
  50    * untrusted code.
  51    */
  52   public synchronized static WhiteBox getWhiteBox() {
  53     SecurityManager sm = System.getSecurityManager();
  54     if (sm != null) {
  55       sm.checkPermission(new WhiteBoxPermission("getInstance"));
  56     }
  57     return instance;
  58   }
  59 
  60   static {
  61     registerNatives();
  62   }
  63 

  64   // Arguments
  65   public native void printHeapSizes();
  66 
  67   // Memory
  68   public native long getObjectAddress(Object o);
  69   public native int  getHeapOopSize();
  70 
  71   // Runtime
  72   // Make sure class name is in the correct format
  73   public boolean isClassAlive(String name) {
  74     return isClassAlive0(name.replace('.', '/'));
  75   }
  76   private native boolean isClassAlive0(String name);
  77 
  78   // G1
  79   public native boolean g1InConcurrentMark();
  80   public native boolean g1IsHumongous(Object o);
  81   public native long    g1NumFreeRegions();
  82   public native int     g1RegionSize();
  83   public native Object[]    parseCommandLine(String commandline, DiagnosticCommand[] args);

  44   /**
  45    * Returns the singleton WhiteBox instance.
  46    *
  47    * The returned WhiteBox object should be carefully guarded
  48    * by the caller, since it can be used to read and write data
  49    * at arbitrary memory addresses. It must never be passed to
  50    * untrusted code.
  51    */
  52   public synchronized static WhiteBox getWhiteBox() {
  53     SecurityManager sm = System.getSecurityManager();
  54     if (sm != null) {
  55       sm.checkPermission(new WhiteBoxPermission("getInstance"));
  56     }
  57     return instance;
  58   }
  59 
  60   static {
  61     registerNatives();
  62   }
  63 
  64   public native void printCompressedOopsHeapInfo();
  65   // Arguments
  66   public native void printHeapSizes();
  67 
  68   // Memory
  69   public native long getObjectAddress(Object o);
  70   public native int  getHeapOopSize();
  71 
  72   // Runtime
  73   // Make sure class name is in the correct format
  74   public boolean isClassAlive(String name) {
  75     return isClassAlive0(name.replace('.', '/'));
  76   }
  77   private native boolean isClassAlive0(String name);
  78 
  79   // G1
  80   public native boolean g1InConcurrentMark();
  81   public native boolean g1IsHumongous(Object o);
  82   public native long    g1NumFreeRegions();
  83   public native int     g1RegionSize();
  84   public native Object[]    parseCommandLine(String commandline, DiagnosticCommand[] args);