ObjectModel (Jikes RVM API)

java.lang.Object
- org.mmtk.vm.ObjectModel
- - org.jikesrvm.mm.mmtk.ObjectModel

public final class ObjectModel
extends ObjectModel

Constructor Summary

Constructors
Constructor and Description

ObjectModel()

Constructors
Constructor and Description
`ObjectModel()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`attemptAvailableBits(ObjectReference object, Word oldVal, Word newVal)` Attempts to set the bits available for memory manager use in an object.
`ObjectReference`	`copy(ObjectReference from, int allocator)` Copy an object using a plan's allocCopy to get space and install the forwarding pointer.
`private ObjectReference`	`copyArray(ObjectReference from, TIB tib, RVMArray type, int allocator)`
`private ObjectReference`	`copyScalar(ObjectReference from, TIB tib, RVMClass type, int allocator)`
`Address`	`copyTo(ObjectReference from, ObjectReference to, Address region)` Copy an object to be pointer to by the to address.
`void`	`dumpObject(ObjectReference object)` Dump debugging information for an object.
`Offset`	`GC_HEADER_OFFSET()` Gets the offset of the memory management header from the object reference address.
`int`	`getAlignOffsetWhenCopied(ObjectReference object)` Return the alignment offset requirements for a copy of this object
`int`	`getAlignWhenCopied(ObjectReference object)` Return the alignment requirement for a copy of this object
`protected Offset`	`getArrayBaseOffset()`
`int`	`getArrayLength(ObjectReference object)` Get the length of an array object.
`int`	`getCurrentSize(ObjectReference object)` Return the size used by an object
`ObjectReference`	`getNextObject(ObjectReference object)`
`Address`	`getObjectEndAddress(ObjectReference object)` Gets a pointer to the address just past the end of the object.
`ObjectReference`	`getObjectFromStartAddress(Address start)`
`(package private) static int`	`getObjectSize(ObjectReference object)` Return the size of a given object, in bytes
`ObjectReference`	`getReferenceWhenCopiedTo(ObjectReference from, Address to)` Return the reference that an object will be referred to after it is copied to the specified region.
`int`	`getSizeWhenCopied(ObjectReference object)` Return the size required to copy an object
`byte[]`	`getTypeDescriptor(ObjectReference ref)` Get the type descriptor for an object.
`boolean`	`isAcyclic(ObjectReference typeRef)` Checks if a reference of the given type in another object is inherently acyclic.
`boolean`	`isArray(ObjectReference object)`
`boolean`	`isPrimitiveArray(ObjectReference object)`
`Address`	`objectStartRef(ObjectReference object)` Returns the lowest address of the storage associated with an object.
`Word`	`prepareAvailableBits(ObjectReference object)` Gets the value of bits available for memory manager use in an object, in preparation for setting those bits.
`Word`	`readAvailableBitsWord(ObjectReference object)` Read the bits available for memory manager use in an object.
`byte`	`readAvailableByte(ObjectReference object)` Read the byte available for memory manager use in an object.
`Address`	`refToAddress(ObjectReference object)` Returns an address guaranteed to be inside the storage assocatied with and object.
`void`	`setAvailableBit(ObjectReference object, int idx, boolean flag)` Sets a bit available for memory manager use in an object.
`boolean`	`testAvailableBit(ObjectReference object, int idx)` Tests a bit available for memory manager use in an object.
`void`	`writeAvailableBitsWord(ObjectReference object, Word val)` Sets the bits available for memory manager use in an object.
`void`	`writeAvailableByte(ObjectReference object, byte val)` Sets the byte available for memory manager use in an object.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ObjectModel
```
public ObjectModel()
```
- Method Detail
  - getArrayBaseOffset
```
protected Offset getArrayBaseOffset()
```
    Specified by:
    
    getArrayBaseOffset in class ObjectModel
    
    Returns:
    
    The offset from array reference to element zero
  - copy
```
public ObjectReference copy(ObjectReference from,
                            int allocator)
```
    Description copied from class: ObjectModel
    
    Copy an object using a plan's allocCopy to get space and install the forwarding pointer. On entry, from must have been reserved for copying by the caller. This method calls the plan's getStatusForCopy() method to establish a new status word for the copied object and postCopy() to allow the plan to perform any post copy actions.
    
    Specified by:
    
    copy in class ObjectModel
    
    Parameters:
    
    from - the address of the object to be copied
    
    allocator - The allocator to use.
    
    Returns:
    
    the address of the new object
  - copyScalar
```
private ObjectReference copyScalar(ObjectReference from,
                                   TIB tib,
                                   RVMClass type,
                                   int allocator)
```
  - copyArray
```
private ObjectReference copyArray(ObjectReference from,
                                  TIB tib,
                                  RVMArray type,
                                  int allocator)
```
  - getObjectSize
```
static int getObjectSize(ObjectReference object)
```
    Return the size of a given object, in bytes
    
    Parameters:
    
    object - The object whose size is being queried
    
    Returns:
    
    The size (in bytes) of the given object.
  - copyTo
```
public Address copyTo(ObjectReference from,
                      ObjectReference to,
                      Address region)
```
    Description copied from class: ObjectModel
    
    Copy an object to be pointer to by the to address. This is required for delayed-copy collectors such as compacting collectors. During the collection, MMTk reserves a region in the heap for an object as per requirements found from ObjectModel and then asks ObjectModel to determine what the object's reference will be post-copy.
    
    Specified by:
    
    copyTo in class ObjectModel
    
    Parameters:
    
    region - The start (or an address less than) the region that was reserved for this object.
    
    from - the address of the object to be copied
    
    to - The target location.
    
    Returns:
    
    Address The address past the end of the copied object
  - getReferenceWhenCopiedTo
```
public ObjectReference getReferenceWhenCopiedTo(ObjectReference from,
                                                Address to)
```
    Description copied from class: ObjectModel
    
    Return the reference that an object will be referred to after it is copied to the specified region. Used in delayed-copy collectors such as compacting collectors.
    
    Specified by:
    
    getReferenceWhenCopiedTo in class ObjectModel
    
    Parameters:
    
    from - The object to be copied.
    
    to - The region to be copied to.
    
    Returns:
    
    The resulting reference.
  - getObjectEndAddress
```
public Address getObjectEndAddress(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Gets a pointer to the address just past the end of the object.
    
    Specified by:
    
    getObjectEndAddress in class ObjectModel
    
    Parameters:
    
    object - The object
    
    Returns:
    
    the address of the first word after the the object
  - getSizeWhenCopied
```
public int getSizeWhenCopied(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Return the size required to copy an object
    
    Specified by:
    
    getSizeWhenCopied in class ObjectModel
    
    Parameters:
    
    object - The object whose size is to be queried
    
    Returns:
    
    The size required to copy obj
  - getAlignWhenCopied
```
public int getAlignWhenCopied(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Return the alignment requirement for a copy of this object
    
    Specified by:
    
    getAlignWhenCopied in class ObjectModel
    
    Parameters:
    
    object - The object whose size is to be queried
    
    Returns:
    
    The alignment required for a copy of obj
  - getAlignOffsetWhenCopied
```
public int getAlignOffsetWhenCopied(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Return the alignment offset requirements for a copy of this object
    
    Specified by:
    
    getAlignOffsetWhenCopied in class ObjectModel
    
    Parameters:
    
    object - The object whose size is to be queried
    
    Returns:
    
    The alignment offset required for a copy of obj
  - getCurrentSize
```
public int getCurrentSize(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Return the size used by an object
    
    Specified by:
    
    getCurrentSize in class ObjectModel
    
    Parameters:
    
    object - The object whose size is to be queried
    
    Returns:
    
    The size of obj
  - getNextObject
```
public ObjectReference getNextObject(ObjectReference object)
```
    Specified by:
    
    getNextObject in class ObjectModel
    
    Parameters:
    
    object - the current object
    
    Returns:
    
    the object reference for the next object in the heap under contiguous allocation
  - getObjectFromStartAddress
```
public ObjectReference getObjectFromStartAddress(Address start)
```
    Specified by:
    
    getObjectFromStartAddress in class ObjectModel
    
    Parameters:
    
    start - the start address of the object
    
    Returns:
    
    an object reference from knowledge of the low order word
  - getTypeDescriptor
```
public byte[] getTypeDescriptor(ObjectReference ref)
```
    Description copied from class: ObjectModel
    
    Get the type descriptor for an object.
    
    Specified by:
    
    getTypeDescriptor in class ObjectModel
    
    Parameters:
    
    ref - address of the object
    
    Returns:
    
    byte array with the type descriptor
  - getArrayLength
```
public int getArrayLength(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Get the length of an array object.
    
    Specified by:
    
    getArrayLength in class ObjectModel
    
    Parameters:
    
    object - address of the object
    
    Returns:
    
    The array length, in elements
  - isArray
```
public boolean isArray(ObjectReference object)
```
    Specified by:
    
    isArray in class ObjectModel
    
    Parameters:
    
    object - address of the object
    
    Returns:
    
    whether the passed object is an array
  - isPrimitiveArray
```
public boolean isPrimitiveArray(ObjectReference object)
```
    Specified by:
    
    isPrimitiveArray in class ObjectModel
    
    Parameters:
    
    object - address of the object
    
    Returns:
    
    whether the passed object is a primitive array
  - testAvailableBit
```
public boolean testAvailableBit(ObjectReference object,
                                int idx)
```
    Tests a bit available for memory manager use in an object.
    
    Parameters:
    
    object - the address of the object
    
    idx - the index of the bit
    
    Returns:
    
    true if argument bit is 1, false if it is 0
  - setAvailableBit
```
public void setAvailableBit(ObjectReference object,
                            int idx,
                            boolean flag)
```
    Sets a bit available for memory manager use in an object.
    
    Parameters:
    
    object - the address of the object
    
    idx - the index of the bit
    
    flag - true to set the bit to 1, false to set it to 0
  - attemptAvailableBits
```
public boolean attemptAvailableBits(ObjectReference object,
                                    Word oldVal,
                                    Word newVal)
```
    Description copied from class: ObjectModel
    
    Attempts to set the bits available for memory manager use in an object. The attempt will only be successful if the current value of the bits matches oldVal. The comparison with the current value and setting are atomic with respect to other allocators.
    
    Specified by:
    
    attemptAvailableBits in class ObjectModel
    
    Parameters:
    
    object - the address of the object
    
    oldVal - the required current value of the bits
    
    newVal - the desired new value of the bits
    
    Returns:
    
    true if the bits were set, false otherwise
  - prepareAvailableBits
```
public Word prepareAvailableBits(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Gets the value of bits available for memory manager use in an object, in preparation for setting those bits.
    
    Specified by:
    
    prepareAvailableBits in class ObjectModel
    
    Parameters:
    
    object - the address of the object
    
    Returns:
    
    the value of the bits
  - writeAvailableByte
```
public void writeAvailableByte(ObjectReference object,
                               byte val)
```
    Description copied from class: ObjectModel
    
    Sets the byte available for memory manager use in an object.
    
    Specified by:
    
    writeAvailableByte in class ObjectModel
    
    Parameters:
    
    object - the address of the object
    
    val - the new value of the byte
  - readAvailableByte
```
public byte readAvailableByte(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Read the byte available for memory manager use in an object.
    
    Specified by:
    
    readAvailableByte in class ObjectModel
    
    Parameters:
    
    object - the address of the object
    
    Returns:
    
    the value of the byte
  - writeAvailableBitsWord
```
public void writeAvailableBitsWord(ObjectReference object,
                                   Word val)
```
    Description copied from class: ObjectModel
    
    Sets the bits available for memory manager use in an object.
    
    Specified by:
    
    writeAvailableBitsWord in class ObjectModel
    
    Parameters:
    
    object - the address of the object
    
    val - the new value of the bits
  - readAvailableBitsWord
```
public Word readAvailableBitsWord(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Read the bits available for memory manager use in an object.
    
    Specified by:
    
    readAvailableBitsWord in class ObjectModel
    
    Parameters:
    
    object - the address of the object
    
    Returns:
    
    the value of the bits
  - GC_HEADER_OFFSET
```
public Offset GC_HEADER_OFFSET()
```
    Description copied from class: ObjectModel
    
    Gets the offset of the memory management header from the object reference address. XXX The object model / memory manager interface should be improved so that the memory manager does not need to know this.
    
    Specified by:
    
    GC_HEADER_OFFSET in class ObjectModel
    
    Returns:
    
    the offset, relative the object reference address
  - objectStartRef
```
public Address objectStartRef(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Returns the lowest address of the storage associated with an object.
    
    Specified by:
    
    objectStartRef in class ObjectModel
    
    Parameters:
    
    object - the reference address of the object
    
    Returns:
    
    the lowest address of the object
  - refToAddress
```
public Address refToAddress(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Returns an address guaranteed to be inside the storage assocatied with and object.
    
    Specified by:
    
    refToAddress in class ObjectModel
    
    Parameters:
    
    object - the reference address of the object
    
    Returns:
    
    an address inside the object
  - isAcyclic
```
public boolean isAcyclic(ObjectReference typeRef)
```
    Description copied from class: ObjectModel
    
    Checks if a reference of the given type in another object is inherently acyclic. The type is given as a TIB.
    
    Specified by:
    
    isAcyclic in class ObjectModel
    
    Parameters:
    
    typeRef - the type of the reference (as a TIB)
    
    Returns:
    
    true if a reference of the type is inherently acyclic
  - dumpObject
```
public void dumpObject(ObjectReference object)
```
    Description copied from class: ObjectModel
    
    Dump debugging information for an object.
    
    Specified by:
    
    dumpObject in class ObjectModel
    
    Parameters:
    
    object - The object whose information is to be dumped

Class ObjectModel

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

ObjectModel

Method Detail

getArrayBaseOffset

copy

copyScalar

copyArray

getObjectSize

copyTo

getReferenceWhenCopiedTo

getObjectEndAddress

getSizeWhenCopied

getAlignWhenCopied

getAlignOffsetWhenCopied

getCurrentSize

getNextObject

getObjectFromStartAddress

getTypeDescriptor

getArrayLength

isArray

isPrimitiveArray

testAvailableBit

setAvailableBit

attemptAvailableBits

prepareAvailableBits

writeAvailableByte

readAvailableByte

writeAvailableBitsWord

readAvailableBitsWord

GC_HEADER_OFFSET

objectStartRef

refToAddress

isAcyclic

dumpObject