org.mmtk.utility.heap

Class VMRequest

java.lang.Object

org.mmtk.utility.heap.VMRequest

public final class VMRequest
extends Object

This class manages the encoding and decoding of virtual memory requests.

By encapsulating this aspect of the construction of a space, we greatly reduce the number of constructors required.

Field Summary

Fields

Modifier and Type	Field and Description
Extent	extent
float	frac
static int	REQUEST_DISCONTIGUOUS
static int	REQUEST_EXTENT
static int	REQUEST_FIXED
static int	REQUEST_FRACTION
Address	start
boolean	top
int	type

Constructor Summary

Constructors

Modifier	Constructor and Description
private	VMRequest(int type, Address start, Extent bytes, float frac, boolean top)

Method Summary

Modifier and Type	Method and Description
static VMRequest	discontiguous() A request for a discontiguous region of memory
static VMRequest	fixed(Address start, Extent extent) A request for an explicit region of memory
static VMRequest	fixedExtent(Extent extent, boolean top) A request for a number of bytes of memory, optionally requesting the highest available.
static VMRequest	fixedSize(int mb) A request for a number of megabytes of memory
static VMRequest	fraction(float frac) A request for a fraction of available memory
static VMRequest	highFixedSize(int mb) A request for a number of megabytes of memory at the highest available addresses
static VMRequest	highFraction(float frac) A request for a fraction of available memory, optionally requesting the highest available.
boolean	isDiscontiguous() Is this a discontiguous space request?

Methods inherited from class java.lang.Object

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

Field Detail

REQUEST_DISCONTIGUOUS

public static final int REQUEST_DISCONTIGUOUS

See Also:

Constant Field Values

REQUEST_FIXED

public static final int REQUEST_FIXED

See Also:

Constant Field Values

REQUEST_EXTENT

public static final int REQUEST_EXTENT

See Also:

Constant Field Values

REQUEST_FRACTION

public static final int REQUEST_FRACTION

See Also:

Constant Field Values

type

public final int type

start

public final Address start

extent

public final Extent extent

frac

public final float frac

top

public final boolean top

Constructor Detail

VMRequest

private VMRequest(int type,
                  Address start,
                  Extent bytes,
                  float frac,
                  boolean top)

Method Detail

isDiscontiguous

public boolean isDiscontiguous()

Is this a discontiguous space request?

Returns:

true if this is a discontiguous space request, false otherwise

discontiguous

public static VMRequest discontiguous()

A request for a discontiguous region of memory

Returns:

The request object

fixed

public static VMRequest fixed(Address start,
                              Extent extent)

A request for an explicit region of memory

Parameters:

start - The start of the region

extent - The size of the region

Returns:

The request object

fixedSize

public static VMRequest fixedSize(int mb)

A request for a number of megabytes of memory

Parameters:

mb - The number of megabytes

Returns:

The request object

fraction

public static VMRequest fraction(float frac)

A request for a fraction of available memory

Parameters:

frac - The fraction

Returns:

The request object

highFixedSize

public static VMRequest highFixedSize(int mb)

A request for a number of megabytes of memory at the highest available addresses

Parameters:

mb - The number of megabytes

Returns:

The request object

highFraction

public static VMRequest highFraction(float frac)

A request for a fraction of available memory, optionally requesting the highest available.

Parameters:

frac - The fraction

Returns:

The request object

fixedExtent

public static VMRequest fixedExtent(Extent extent,
                                    boolean top)

A request for a number of bytes of memory, optionally requesting the highest available.

Parameters:

extent - The number of bytes

top - True to request high memory

Returns:

The request object