Package org.openjdk.jol.vm

Class HotspotUnsafe

java.lang.Object

org.openjdk.jol.vm.HotspotUnsafe

All Implemented Interfaces:

VirtualMachine

class HotspotUnsafe
extends java.lang.Object
implements VirtualMachine

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	HotspotUnsafe.Sizes

Field Summary

Fields

Modifier and Type	Field	Description
private int	addressSize
private int	arrayHeaderSize
private long	arrayObjectBase
private java.lang.ThreadLocal<java.lang.Object[]>	BUFFERS
private boolean	compressedKlassOopsEnabled
private boolean	compressedOopsEnabled
private java.lang.instrument.Instrumentation	instrumentation
private boolean	isAccurate
private boolean	lilliputVM
private static boolean	MAGIC_FIELD_OFFSET
private static java.lang.String	MAGIC_FIELD_OFFSET_OPTION
private boolean	mfoInitialized
private java.lang.reflect.Method	mfoMethod
private java.lang.Object	mfoUnsafe
private long	narrowKlassBase
private int	narrowKlassShift
private long	narrowOopBase
private int	narrowOopShift
private int	objectAlignment
private int	objectHeaderSize
private int	oopSize
private HotspotUnsafe.Sizes	sizes
private sun.misc.Unsafe	U

Constructor Summary

Constructors

Constructor	Description
HotspotUnsafe(sun.misc.Unsafe u, java.lang.instrument.Instrumentation inst)
HotspotUnsafe(sun.misc.Unsafe u, java.lang.instrument.Instrumentation inst, UniverseData saDetails)

Method Summary

Modifier and Type	Method	Description
long	addressOf(java.lang.Object o)	Returns the machine address of the given object.
int	addressSize()	Returns native address size.
int	arrayBaseOffset(java.lang.String arrayComponentKlass)	Returns the array base offset for an array of a given component type.
int	arrayHeaderSize()	Returns the array header size.
int	arrayIndexScale(java.lang.String arrayComponentKlass)	Returns the array index scale for an array of a given component type.
int	classPointerSize()	Returns class pointer size.
java.lang.String	details()	Returns the informational details about the current VM mode
long	fieldOffset(java.lang.reflect.Field field)	Returns the field offset for a given field, starting from the object base.
private java.lang.String	formatAddressAsHexByAddressSize(long address)
boolean	getBoolean(java.lang.Object obj, long offset)	Reads a boolean off the object at given offset.
byte	getByte(java.lang.Object obj, long offset)	Reads a byte off the object at given offset.
char	getChar(java.lang.Object obj, long offset)	Reads a char off the object at given offset.
double	getDouble(java.lang.Object obj, long offset)	Reads a double off the object at given offset.
float	getFloat(java.lang.Object obj, long offset)	Reads a float off the object at given offset.
int	getInt(java.lang.Object obj, long offset)	Reads an int off the object at given offset.
long	getLong(java.lang.Object obj, long offset)	Reads a long off the object at given offset.
private int	getMinDiff(java.lang.Class<?> klass)
java.lang.Object	getObject(java.lang.Object obj, long offset)	Reads an object off the object at given offset.
short	getShort(java.lang.Object obj, long offset)	Reads a short off the object at given offset.
private int	guessAlignment()
private int	guessHeaderSize()
private boolean	guessLilliput(int addressSize)
private long	guessNarrowOopBase()
private int	guessOopSize()
private static java.lang.Object	instantiateType(int type)
private long	magicFieldOffset(java.lang.reflect.Field field, java.lang.RuntimeException original)
int	objectAlignment()	Returns the object alignment.
int	objectHeaderSize()	Returns the object header size.
long	sizeOf(java.lang.Object o)	Returns the shallow size of the given object.
long	sizeOfField(java.lang.String klassName)	Returns the size of a field holding the type.
private long	toJvmAddress(long address)
private long	toJvmKlassAddress(long address)
private long	toJvmOopAddress(long address)
private long	toNativeAddress(long address)
private long	toNativeKlassAddress(long address)
private long	toNativeOopAddress(long address)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAGIC_FIELD_OFFSET_OPTION

private static final java.lang.String MAGIC_FIELD_OFFSET_OPTION

See Also:

Constant Field Values

MAGIC_FIELD_OFFSET

private static final boolean MAGIC_FIELD_OFFSET

U

private final sun.misc.Unsafe U

instrumentation

private final java.lang.instrument.Instrumentation instrumentation

isAccurate

private final boolean isAccurate

addressSize

private final int addressSize

objectAlignment

private final int objectAlignment

oopSize

private final int oopSize

compressedOopsEnabled

private final boolean compressedOopsEnabled

narrowOopBase

private final long narrowOopBase

narrowOopShift

private final int narrowOopShift

compressedKlassOopsEnabled

private final boolean compressedKlassOopsEnabled

narrowKlassBase

private final long narrowKlassBase

narrowKlassShift

private final int narrowKlassShift

arrayHeaderSize

private final int arrayHeaderSize

objectHeaderSize

private final int objectHeaderSize

arrayObjectBase

private final long arrayObjectBase

sizes

private final HotspotUnsafe.Sizes sizes

lilliputVM

private final boolean lilliputVM

mfoInitialized

private volatile boolean mfoInitialized

mfoUnsafe

private java.lang.Object mfoUnsafe

mfoMethod

private java.lang.reflect.Method mfoMethod

BUFFERS

private final java.lang.ThreadLocal<java.lang.Object[]> BUFFERS

Constructor Detail

HotspotUnsafe

HotspotUnsafe(sun.misc.Unsafe u,
              java.lang.instrument.Instrumentation inst,
              UniverseData saDetails)

HotspotUnsafe

HotspotUnsafe(sun.misc.Unsafe u,
              java.lang.instrument.Instrumentation inst)

Method Detail

guessLilliput

private boolean guessLilliput(int addressSize)

guessNarrowOopBase

private long guessNarrowOopBase()

guessOopSize

private int guessOopSize()

guessHeaderSize

private int guessHeaderSize()

sizeOf

public long sizeOf(java.lang.Object o)

Description copied from interface: VirtualMachine

Returns the shallow size of the given object.

Specified by:

sizeOf in interface VirtualMachine

Parameters:

o - object

Returns:

shallow size

sizeOfField

public long sizeOfField(java.lang.String klassName)

Description copied from interface: VirtualMachine

Returns the size of a field holding the type.

Specified by:

sizeOfField in interface VirtualMachine

Parameters:

klassName - klass

Returns:

slot size

objectAlignment

public int objectAlignment()

Description copied from interface: VirtualMachine

Returns the object alignment.

Specified by:

objectAlignment in interface VirtualMachine

Returns:

object alignment

arrayHeaderSize

public int arrayHeaderSize()

Description copied from interface: VirtualMachine

Returns the array header size. This includes the array length pseudofield.

Specified by:

arrayHeaderSize in interface VirtualMachine

Returns:

array header size

objectHeaderSize

public int objectHeaderSize()

Description copied from interface: VirtualMachine

Returns the object header size.

Specified by:

objectHeaderSize in interface VirtualMachine

Returns:

header size

getMinDiff

private int getMinDiff(java.lang.Class<?> klass)

addressSize

public int addressSize()

Description copied from interface: VirtualMachine

Returns native address size.

Specified by:

addressSize in interface VirtualMachine

Returns:

address size in bytes

classPointerSize

public int classPointerSize()

Description copied from interface: VirtualMachine

Returns class pointer size.

Specified by:

classPointerSize in interface VirtualMachine

Returns:

class pointer size, in bytes

details

public java.lang.String details()

Description copied from interface: VirtualMachine

Returns the informational details about the current VM mode

Specified by:

details in interface VirtualMachine

Returns:

String details

instantiateType

private static java.lang.Object instantiateType(int type)

guessAlignment

private int guessAlignment()

addressOf

public long addressOf(java.lang.Object o)

Description copied from interface: VirtualMachine

Returns the machine address of the given object. Note that in some VM modes, the addresses would be guesses, based on internal experiments which would try to figure out the reference encoding. Use this data with care. Doing the naked memory access on the result of this method may corrupt the memory.

Specified by:

addressOf in interface VirtualMachine

Parameters:

o - object

Returns:

address

arrayBaseOffset

public int arrayBaseOffset(java.lang.String arrayComponentKlass)

Description copied from interface: VirtualMachine

Returns the array base offset for an array of a given component type.

Specified by:

arrayBaseOffset in interface VirtualMachine

Parameters:

arrayComponentKlass - component type

Returns:

base offset

arrayIndexScale

public int arrayIndexScale(java.lang.String arrayComponentKlass)

Description copied from interface: VirtualMachine

Returns the array index scale for an array of a given component type.

Specified by:

arrayIndexScale in interface VirtualMachine

Parameters:

arrayComponentKlass - component type

Returns:

index scale

getBoolean

public boolean getBoolean(java.lang.Object obj,
                          long offset)

Description copied from interface: VirtualMachine

Reads a boolean off the object at given offset.

Specified by:

getBoolean in interface VirtualMachine

Parameters:

obj - instance

offset - offset

Returns:

the boolean

getByte

public byte getByte(java.lang.Object obj,
                    long offset)

Description copied from interface: VirtualMachine

Reads a byte off the object at given offset.

Specified by:

getByte in interface VirtualMachine

Parameters:

obj - instance

offset - offset

Returns:

the byte

getShort

public short getShort(java.lang.Object obj,
                      long offset)

Description copied from interface: VirtualMachine

Reads a short off the object at given offset.

Specified by:

getShort in interface VirtualMachine

Parameters:

obj - instance

offset - offset

Returns:

the short

getChar

public char getChar(java.lang.Object obj,
                    long offset)

Description copied from interface: VirtualMachine

Reads a char off the object at given offset.

Specified by:

getChar in interface VirtualMachine

Parameters:

obj - instance

offset - offset

Returns:

the char

getInt

public int getInt(java.lang.Object obj,
                  long offset)

Description copied from interface: VirtualMachine

Reads an int off the object at given offset.

Specified by:

getInt in interface VirtualMachine

Parameters:

obj - instance

offset - offset

Returns:

the int

getFloat

public float getFloat(java.lang.Object obj,
                      long offset)

Description copied from interface: VirtualMachine

Reads a float off the object at given offset.

Specified by:

getFloat in interface VirtualMachine

Parameters:

obj - instance

offset - offset

Returns:

the float

getLong

public long getLong(java.lang.Object obj,
                    long offset)

Description copied from interface: VirtualMachine

Reads a long off the object at given offset.

Specified by:

getLong in interface VirtualMachine

Parameters:

obj - instance

offset - offset

Returns:

the long

getDouble

public double getDouble(java.lang.Object obj,
                        long offset)

Description copied from interface: VirtualMachine

Reads a double off the object at given offset.

Specified by:

getDouble in interface VirtualMachine

Parameters:

obj - instance

offset - offset

Returns:

the double

getObject

public java.lang.Object getObject(java.lang.Object obj,
                                  long offset)

Description copied from interface: VirtualMachine

Reads an object off the object at given offset.

Specified by:

getObject in interface VirtualMachine

Parameters:

obj - instance

offset - offset

Returns:

the Object

fieldOffset

public long fieldOffset(java.lang.reflect.Field field)

Description copied from interface: VirtualMachine

Returns the field offset for a given field, starting from the object base.

Specified by:

fieldOffset in interface VirtualMachine

Parameters:

field - field

Returns:

offset

magicFieldOffset

private long magicFieldOffset(java.lang.reflect.Field field,
                              java.lang.RuntimeException original)

toNativeAddress

private long toNativeAddress(long address)

toJvmAddress

private long toJvmAddress(long address)

toNativeOopAddress

private long toNativeOopAddress(long address)

toJvmOopAddress

private long toJvmOopAddress(long address)

toNativeKlassAddress

private long toNativeKlassAddress(long address)

toJvmKlassAddress

private long toJvmKlassAddress(long address)

formatAddressAsHexByAddressSize

private java.lang.String formatAddressAsHexByAddressSize(long address)