xdean.jex.util.lang

类 UnsafeUtil

java.lang.Object

xdean.jex.util.lang.UnsafeUtil

public class UnsafeUtil
extends Object

构造器概要

构造器

构造器和说明
UnsafeUtil()

方法概要

限定符和类型	方法和说明
static long	addressOf(Object o) Get the memory address of the given object.
static long	getHeaderSize()
static sun.misc.Unsafe	getUnsafe()
static boolean	isUsecompressedOops() Determined whether the vm use -XX:+UseCompressedOops.
static long	refSize() Get the size of reference.
static long	refSizeOf(Class<?> clz) Get the size of reference.
static long	shallowSizeOf(Class<?> clz) Measure the SHALLOW size of the given class's instance.
static long	shallowSizeOf(Object o) SHALLOW size of the given object.
static long	sizeOf(Object o) HEAP size of the given object.

从类继承的方法 java.lang.Object

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

构造器详细资料

UnsafeUtil

public UnsafeUtil()

方法详细资料

getUnsafe

public static sun.misc.Unsafe getUnsafe()

addressOf

public static long addressOf(Object o)

Get the memory address of the given object.

参数:

o -

返回:

shallowSizeOf

public static long shallowSizeOf(Class<?> clz)

Measure the SHALLOW size of the given class's instance.
If given an array class, only return the base offset (size of array of length 0).
For array class, use shallowSizeOf(Object).

参数:

clz -

返回:

shallowSizeOf

public static long shallowSizeOf(Object o)

SHALLOW size of the given object.
If given a primitive type, the result will be incorrect.
For primitive type, use shallowSizeOf(Class).

参数:

o -

返回:

sizeOf

public static long sizeOf(Object o)

HEAP size of the given object.
If given a primitive type, the result will be incorrect because auto-box.
For primitive type, use shallowSizeOf(Class).

参数:

o -

返回:

refSize

public static long refSize()

Get the size of reference.(considered UseCompressedOops)
If you want to get the actual address size, use Unsafe.addressSize()

返回:

ref size

refSizeOf

public static long refSizeOf(Class<?> clz)

Get the size of reference.(considered UseCompressedOops)
If the class is primitive type, return it's actual size.

参数:

clz -

返回:

getHeaderSize

public static long getHeaderSize()

isUsecompressedOops

public static boolean isUsecompressedOops()

Determined whether the vm use -XX:+UseCompressedOops.

返回:

If it's running on a 32 bit vm, it also return true;