Class GCArrayletObjectModelBase

java.lang.Object

com.ibm.j9ddr.vm29.j9.gc.GCBase

com.ibm.j9ddr.vm29.j9.gc.GCArrayletObjectModelBase

public abstract class GCArrayletObjectModelBase
extends GCBase

Field Summary

Fields

Modifier and Type	Field	Description
protected UDATA	arrayletLeafLogSize
protected UDATA	arrayletLeafSize
protected UDATA	arrayletLeafSizeMask
protected com.ibm.j9ddr.vm29.pointer.generated.GC_ArrayletObjectModelPointer	arrayletObjectModel
protected VoidPointer	arrayletRangeBase
protected VoidPointer	arrayletRangeTop
protected UDATA	largestDesirableArraySpineSize

Constructor Summary

Constructors

Constructor	Description
GCArrayletObjectModelBase()

Method Summary

Modifier and Type	Method	Description
protected UDATA	externalArrayletsSize(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Get the total number of bytes consumed by arraylets external to the given indexable object.
static com.ibm.j9ddr.vm29.j9.gc.GCArrayObjectModel	from()	Factory method to construct an appropriate array object model.
protected long	getArrayLayout(com.ibm.j9ddr.vm29.pointer.generated.J9ArrayClassPointer clazz, UDATA dataSizeInBytes)	Get the layout of an indexable object given it's class, data size in bytes and the subspace's largestDesirableSpine.
protected long	getArrayLayout(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Get the layout for the given indexable object
ObjectReferencePointer	getArrayoidPointer(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Returns the address of first arraylet leaf slot in the spine
VoidPointer	getDataPointerForContiguous(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Returns the address of first data slot in the array
UDATA	getDataSizeInBytes(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Returns the size of data in an indexable object, in bytes, including leaves, excluding the header.
VoidPointer	getElementAddress(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array, int elementIndex, int elementSize)	Returns the address of the element at elementIndex logical offset into indexableObjectPointer, assuming that each element is dataSize bytes.
UDATA	getHashcodeOffset(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Returns the offset of the hashcode slot, in bytes, from the beginning of the header.
protected UDATA	getHeaderSize(long layout)	Get the spine size without header for an arraylet with these properties
UDATA	getHeaderSize(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Returns the header size of a given indexable object.
abstract UDATA	getSizeInBytesWithHeader(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Returns the size of an indexable object, in bytes, including the header.
UDATA	getSizeInElements(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Returns the size of an indexable object in elements.
UDATA	getSizeInSlotsWithHeader(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Returns the size of an indexable object, in slots, including the header.
protected UDATA	getSpineSize(long layout, UDATA numberArraylets, UDATA dataSize, boolean alignData)	Get the spine size for an arraylet with these properties
protected UDATA	getSpineSize(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Get the spine size for the given indexable object
protected UDATA	getSpineSizeWithoutHeader(long layout, UDATA numberArraylets, UDATA dataSize, boolean alignData)	Get the spine size without header for an arraylet with these properties
abstract UDATA	getTotalFootprintInBytesWithHeader(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer arrayPtr)	Get the total footprint of an object, in bytes, including the object header and all data.
boolean	isInlineContiguousArraylet(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Check the given indexable object is inline contiguous
protected UDATA	numArraylets(UDATA unadjustedDataSizeInBytes)	Return the total number of arraylets for an indexable object with a size of dataInSizeByte, including a (possibly empty) leaf in the spine.
protected UDATA	numExternalArraylets(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)	Return the total number of arraylets for an indexable object, not including the arraylet in the spine.
protected boolean	shouldAlignSpineDataSection(com.ibm.j9ddr.vm29.pointer.generated.J9ArrayClassPointer clazz)	Determines whether or not a spine that represents an object of this class should have its data section aligned.
protected boolean	shouldAlignSpineDataSection(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz)	Determines whether or not a spine that represents an object of this class should have its data section aligned.

Methods declared in class com.ibm.j9ddr.vm29.j9.gc.GCBase

getExtensions, getJavaVM

Methods declared in class java.lang.Object

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

Field Details

arrayletObjectModel

protected com.ibm.j9ddr.vm29.pointer.generated.GC_ArrayletObjectModelPointer arrayletObjectModel

arrayletRangeBase

protected VoidPointer arrayletRangeBase

arrayletRangeTop

protected VoidPointer arrayletRangeTop

largestDesirableArraySpineSize

protected UDATA largestDesirableArraySpineSize

arrayletLeafSize

protected UDATA arrayletLeafSize

arrayletLeafLogSize

protected UDATA arrayletLeafLogSize

arrayletLeafSizeMask

protected UDATA arrayletLeafSizeMask

Constructor Details

GCArrayletObjectModelBase

public GCArrayletObjectModelBase()
                          throws CorruptDataException

Throws:

CorruptDataException

Method Details

getSpineSize

protected UDATA getSpineSize(long layout,
 UDATA numberArraylets,
 UDATA dataSize,
 boolean alignData)
                      throws CorruptDataException

Get the spine size for an arraylet with these properties

Parameters:

layout - The layout of the indexable object

numberArraylets - Number of arraylets for this indexable object

dataSize - How many elements are in the indexable object

alignData - Should the data section be aligned

J9Class - The class of the array.

Returns:

spineSize The actual size in byte of the spine

Throws:

CorruptDataException

getSizeInElements

public UDATA getSizeInElements(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                        throws CorruptDataException

Returns the size of an indexable object in elements.

Parameters:

array - Pointer to the indexable object whose size is required

Returns:

Size of object in elements

Throws:

CorruptDataException

getHeaderSize

protected UDATA getHeaderSize(long layout)

Get the spine size without header for an arraylet with these properties

Parameters:

layout - The layout of the indexable object

numberArraylets - Number of arraylets for this indexable object

dataSize - How many elements are in the indexable object

alignData - Should the data section be aligned

Returns:

spineSize The actual size in byte of the spine

getHeaderSize

public UDATA getHeaderSize(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                    throws CorruptDataException

Returns the header size of a given indexable object. The arraylet layout is determined base on "small" size.

Parameters:

array - Ptr to an array for which header size will be returned

Returns:

Size of header in bytes

Throws:

CorruptDataException

getSpineSizeWithoutHeader

protected UDATA getSpineSizeWithoutHeader(long layout,
 UDATA numberArraylets,
 UDATA dataSize,
 boolean alignData)
                                   throws CorruptDataException

Get the spine size without header for an arraylet with these properties

Parameters:

layout - The layout of the indexable object

numberArraylets - Number of arraylets for this indexable object

dataSize - How many elements are in the indexable object

alignData - Should the data section be aligned

Returns:

spineSize The actual size in byte of the spine

Throws:

CorruptDataException

getSpineSize

protected UDATA getSpineSize(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                      throws CorruptDataException

Get the spine size for the given indexable object

Parameters:

objPtr - Pointer to an array object

Returns:

The total size in bytes of objPtr's array spine; includes header, arraylet ptrs, and (if present) padding invalid input: '&' inline data

Throws:

CorruptDataException

getArrayLayout

protected long getArrayLayout(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                       throws CorruptDataException

Get the layout for the given indexable object

Parameters:

objPtr - Pointer to a array object

Returns:

the ArrayLayout for objectPtr

Throws:

CorruptDataException

getArrayLayout

protected long getArrayLayout(com.ibm.j9ddr.vm29.pointer.generated.J9ArrayClassPointer clazz,
 UDATA dataSizeInBytes)
                       throws CorruptDataException

Get the layout of an indexable object given it's class, data size in bytes and the subspace's largestDesirableSpine.

Parameters:

clazz - The class of the object stored in the array.

dataSizeInBytes - the size in bytes of the data of the array.

largestDesirableSpine - The largest desirable spine of the arraylet.

Throws:

CorruptDataException

getDataSizeInBytes

public UDATA getDataSizeInBytes(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                         throws CorruptDataException

Returns the size of data in an indexable object, in bytes, including leaves, excluding the header.

Parameters:

array - Pointer to the indexable object whose size is required

Returns:

Size of object in bytes excluding the header

Throws:

CorruptDataException

getArrayoidPointer

public ObjectReferencePointer getArrayoidPointer(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                                          throws CorruptDataException

Returns the address of first arraylet leaf slot in the spine

Parameters:

array - Ptr to an array

Returns:

Arrayoid ptr

Throws:

CorruptDataException

getDataPointerForContiguous

public VoidPointer getDataPointerForContiguous(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                                        throws CorruptDataException

Returns the address of first data slot in the array

Parameters:

array - pointer to an array

Returns:

Address of first data slot in the array

Throws:

CorruptDataException

getHashcodeOffset

public UDATA getHashcodeOffset(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                        throws CorruptDataException

Returns the offset of the hashcode slot, in bytes, from the beginning of the header.

Returns:

offset of the hashcode slot

Throws:

CorruptDataException

isInlineContiguousArraylet

public boolean isInlineContiguousArraylet(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                                   throws CorruptDataException

Check the given indexable object is inline contiguous

Parameters:

objPtr - Pointer to an array object

Returns:

true of array is inline contiguous

Throws:

CorruptDataException

shouldAlignSpineDataSection

protected boolean shouldAlignSpineDataSection(com.ibm.j9ddr.vm29.pointer.generated.J9ArrayClassPointer clazz)
                                       throws CorruptDataException

Determines whether or not a spine that represents an object of this class should have its data section aligned.

Parameters:

clazz - The class to check alignment for

Returns:

needAlignment Should the data section be aligned

Throws:

CorruptDataException

shouldAlignSpineDataSection

protected boolean shouldAlignSpineDataSection(com.ibm.j9ddr.vm29.pointer.generated.J9ClassPointer clazz)
                                       throws CorruptDataException

Determines whether or not a spine that represents an object of this class should have its data section aligned.

Parameters:

clazz - The class to check alignment for

Returns:

needAlignment Should the data section be aligned

Throws:

CorruptDataException

getElementAddress

public VoidPointer getElementAddress(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array,
 int elementIndex,
 int elementSize)
                              throws CorruptDataException

Returns the address of the element at elementIndex logical offset into indexableObjectPointer, assuming that each element is dataSize bytes.

Parameters:

array - The array from which we should look-up the address

elementIndex - The logical index number of the element within the array

elementSize - The size, in bytes, of a single element of the array

Returns:

A pointer to the element

Throws:

CorruptDataException

numArraylets

protected UDATA numArraylets(UDATA unadjustedDataSizeInBytes)
                      throws CorruptDataException

Return the total number of arraylets for an indexable object with a size of dataInSizeByte, including a (possibly empty) leaf in the spine.

Parameters:

dataSizeInBytes - size of an array in bytes (not elements)

Returns:

the number of arraylets used for an array of dataSizeInBytes bytes

Throws:

CorruptDataException

numExternalArraylets

protected UDATA numExternalArraylets(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                              throws CorruptDataException

Return the total number of arraylets for an indexable object, not including the arraylet in the spine. Note that discontiguous arrays always have an empty leaf contained in the spine.

Parameters:

array - pointer to array

Returns:

the number of leaf arraylets

Throws:

CorruptDataException

externalArrayletsSize

protected UDATA externalArrayletsSize(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                               throws CorruptDataException

Get the total number of bytes consumed by arraylets external to the given indexable object.

Parameters:

array - Pointer to an array object

Returns:

the number of bytes consumed external to the spine

Throws:

CorruptDataException

from

public static com.ibm.j9ddr.vm29.j9.gc.GCArrayObjectModel from()
                                                        throws CorruptDataException

Factory method to construct an appropriate array object model.

Parameters:

structure - the J9JavaVM structure to use

Returns:

an instance of ArrayObjectModel

Throws:

CorruptDataException

getSizeInBytesWithHeader

public abstract UDATA getSizeInBytesWithHeader(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                                        throws CorruptDataException

Returns the size of an indexable object, in bytes, including the header.

Parameters:

array - Pointer to the indexable object whose size is required

Returns:

Size of object in bytes including the header

Throws:

CorruptDataException

getSizeInSlotsWithHeader

public UDATA getSizeInSlotsWithHeader(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer array)
                               throws CorruptDataException

Returns the size of an indexable object, in slots, including the header.

Parameters:

array - Pointer to the indexable object whose size is required

Returns:

Size of object in slots including the header

Throws:

CorruptDataException

getTotalFootprintInBytesWithHeader

public abstract UDATA getTotalFootprintInBytesWithHeader(com.ibm.j9ddr.vm29.pointer.generated.J9IndexableObjectPointer arrayPtr)
                                                  throws CorruptDataException

Get the total footprint of an object, in bytes, including the object header and all data. If the object has a discontiguous representation, this method should return the size of the root object plus the total of all the discontiguous parts of the object.

Parameters:

arrayPtr - Pointer to an object

Returns:

the total size of an object, in bytes, including discontiguous parts

Throws:

CorruptDataException