javax.realtime.enforce

Class HeapConstraint

java.lang.Object

javax.realtime.enforce.ResourceConstraint<HeapConstraint>

javax.realtime.enforce.HeapConstraint

public class HeapConstraint
extends ResourceConstraint<HeapConstraint>

A constraint to limit the amount of heap memory available to a task.

Since:

RTSJ 2.0

Constructor Summary

Constructors

Constructor and Description
HeapConstraint(RealtimeThreadGroup group, long limit) Create a new contraint for the given RealtimeThreadGroup.

Method Summary

Modifier and Type	Method and Description
long	available() Determine how much of the resource are available for use, i.e., the amount of the limit minus amount lent.
static HeapConstraint	currentConstraint() Determine the processing constraint for the current execution context.
static HeapConstraint	currentConstraint(java.lang.Thread thread) Determine the processing constraint for the give execution context.
static HeapConstraint	currentConstraint(java.lang.ThreadGroup group) Determine the heap constraint for the give execution context.
long	getBudget() Determine the total amount of a memory under the control of this resource constraint instance.
static HeapConstraint	getRootConstraint() Get the root instance for this constraint type.
boolean	isEnforcing() Determine whether or not enforcing is in effect.
void	start() Start applying this constraint to is tasks.
void	stop() Stop applying this constraint to is tasks.
long	used() Determine how much of the resource have been used of the amount available.

Methods inherited from class javax.realtime.enforce.ResourceConstraint

getNotificationHandler, getParent, getRealtimeThreadGroup, governs, governs, governs, setNotificationHandler, visitBorrowers, visitGoverned

Methods inherited from class java.lang.Object

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

Constructor Detail

HeapConstraint

public HeapConstraint(RealtimeThreadGroup group,
                      long limit)

Create a new contraint for the given RealtimeThreadGroup.

Parameters:

group - The RealtimeThreadGroup to govern.

limit - the amount of memory to take from its parent to manage.

Method Detail

getRootConstraint

public static HeapConstraint getRootConstraint()

Get the root instance for this constraint type.

Returns:

the root constraint.

currentConstraint

public static HeapConstraint currentConstraint()

Determine the processing constraint for the current execution context.

Returns:

the constraint for this context.

currentConstraint

public static HeapConstraint currentConstraint(java.lang.Thread thread)

Determine the processing constraint for the give execution context.

Parameters:

thread - The given execution context.

Returns:

the constraint for this context.

currentConstraint

public static HeapConstraint currentConstraint(java.lang.ThreadGroup group)

Determine the heap constraint for the give execution context.

Parameters:

group - The given execution context.

Returns:

the constraint for this context.

isEnforcing

public boolean isEnforcing()

Determine whether or not enforcing is in effect.

Overrides:

isEnforcing in class ResourceConstraint<HeapConstraint>

Returns:

true when yes and false when not.

start

public void start()

Start applying this constraint to is tasks.

Specified by:

start in class ResourceConstraint<HeapConstraint>

stop

public void stop()

Stop applying this constraint to is tasks.

Specified by:

stop in class ResourceConstraint<HeapConstraint>

getBudget

public long getBudget()

Determine the total amount of a memory under the control of this resource constraint instance.

Returns:

the total amount under control of this instance in bytes.

used

public long used()

Determine how much of the resource have been used of the amount available.

Returns:

the amount used in number of bytes.

available

public long available()

Determine how much of the resource are available for use, i.e., the amount of the limit minus amount lent.

Returns:

the amount used in number of bytes.