org.openjdk.jol.util

Class VMSupport

java.lang.Object

org.openjdk.jol.util.VMSupport

public class VMSupport
extends Object

VM support doorway. Contains all the special tricks and methods to poll VM about it's secrets.

Author:

Aleksey Shipilev

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	VMSupport.SizeInfo

Field Summary

Fields

Modifier and Type	Field and Description
static int	ADDRESS_SIZE
static int	BOOLEAN_SIZE
static int	BYTE_SIZE
static int	CHAR_SIZE
static long	COMPRESSED_KLASS_BASE
static int	COMPRESSED_KLASS_SHIFT
static long	COMPRESSED_OOP_BASE
static int	COMPRESSED_OOP_SHIFT
static long	COMPRESSED_REF_BASE
static int	COMPRESSED_REF_SHIFT
static int	DOUBLE_SIZE
static int	FLOAT_SIZE
static int	INT_SIZE
static int	KLASS_OOP_SIZE
static int	LONG_SIZE
static int	OBJ_ALIGNMENT
static int	OBJ_HEADER_SIZE
static int	OOP_SIZE
static int	REF_SIZE
static int	SHORT_SIZE
static sun.misc.Unsafe	U
static boolean	USE_COMPRESSED_KLASS
static boolean	USE_COMPRESSED_OOP
static boolean	USE_COMPRESSED_REFS
static String	VM_NAME

Constructor Summary

Constructors

Constructor and Description
VMSupport()

Method Summary

Methods

Modifier and Type	Method and Description
static long	addressOf(Object o)
static long	addressOf(Object o, int oopSize)
static int	align(int addr)
static String	safeToString(Object o) Produces the toString string, only calling toString() on known types, which do not mutate the instance.
static int	sizeOf(Object o)
static long	toJvmAddress(long address)
static long	toJvmKlassAddress(long address)
static long	toJvmOopAddress(long address)
static long	toNativeAddress(long address)
static long	toNativeKlassAddress(long address)
static long	toNativeOopAddress(long address)
static VMSupport.SizeInfo	tryExactObjectSize(Object o, ClassLayout layout)
static String	vmDetails()

Methods inherited from class java.lang.Object

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

Field Detail

U

public static final sun.misc.Unsafe U

VM_NAME

public static final String VM_NAME

ADDRESS_SIZE

public static final int ADDRESS_SIZE

REF_SIZE

public static final int REF_SIZE

OBJ_ALIGNMENT

public static final int OBJ_ALIGNMENT

OBJ_HEADER_SIZE

public static final int OBJ_HEADER_SIZE

USE_COMPRESSED_REFS

public static final boolean USE_COMPRESSED_REFS

COMPRESSED_REF_BASE

public static final long COMPRESSED_REF_BASE

COMPRESSED_REF_SHIFT

public static final int COMPRESSED_REF_SHIFT

OOP_SIZE

public static final int OOP_SIZE

USE_COMPRESSED_OOP

public static final boolean USE_COMPRESSED_OOP

COMPRESSED_OOP_BASE

public static final long COMPRESSED_OOP_BASE

COMPRESSED_OOP_SHIFT

public static final int COMPRESSED_OOP_SHIFT

KLASS_OOP_SIZE

public static final int KLASS_OOP_SIZE

USE_COMPRESSED_KLASS

public static final boolean USE_COMPRESSED_KLASS

COMPRESSED_KLASS_BASE

public static final long COMPRESSED_KLASS_BASE

COMPRESSED_KLASS_SHIFT

public static final int COMPRESSED_KLASS_SHIFT

BOOLEAN_SIZE

public static final int BOOLEAN_SIZE

BYTE_SIZE

public static final int BYTE_SIZE

CHAR_SIZE

public static final int CHAR_SIZE

DOUBLE_SIZE

public static final int DOUBLE_SIZE

FLOAT_SIZE

public static final int FLOAT_SIZE

INT_SIZE

public static final int INT_SIZE

LONG_SIZE

public static final int LONG_SIZE

SHORT_SIZE

public static final int SHORT_SIZE

Constructor Detail

VMSupport

public VMSupport()

Method Detail

toNativeAddress

public static long toNativeAddress(long address)

toJvmAddress

public static long toJvmAddress(long address)

toNativeOopAddress

public static long toNativeOopAddress(long address)

toJvmOopAddress

public static long toJvmOopAddress(long address)

toNativeKlassAddress

public static long toNativeKlassAddress(long address)

toJvmKlassAddress

public static long toJvmKlassAddress(long address)

align

public static int align(int addr)

vmDetails

public static String vmDetails()

addressOf

public static long addressOf(Object o)

addressOf

public static long addressOf(Object o,
             int oopSize)

tryExactObjectSize

public static VMSupport.SizeInfo tryExactObjectSize(Object o,
                                    ClassLayout layout)

sizeOf

public static int sizeOf(Object o)

safeToString

public static String safeToString(Object o)

Produces the toString string, only calling toString() on known types, which do not mutate the instance.

Parameters:

o - object to process

Returns:

toString