javax.realtime.enforce

Class ThreadConstraint

java.lang.Object

javax.realtime.enforce.ResourceConstraint<ThreadConstraint>

javax.realtime.enforce.ThreadConstraint

public class ThreadConstraint
extends ResourceConstraint<ThreadConstraint>

A class for handling contraining the number of threads that can be created in a realtime thread group. As with ThreadGroup and RealtimeThreadGroup, instances of ProcessingConstraint can be nested. The number of the threads, including threads in subgroups not subject to another ProcessingConstraint instance, can be both tracked and bounded.

Since:

RTSJ 2.0

Constructor Summary

Constructors

Constructor and Description
ThreadConstraint(RealtimeThreadGroup group, int max) Creates a ThreadConstraint to govern a group of threads.

Method Summary

Modifier and Type	Method and Description
int	available() Determine how much of the resource are available for use, i.e., the amount of the limit minus amount lent.
static ThreadConstraint	currentConstraint() Determine the processing constraint for the current execution context.
static ThreadConstraint	currentConstraint(Thread thread) Determine the processing constraint for the give execution context.
static ThreadConstraint	currentConstraint(ThreadGroup group) Determine the processing constraint for the give execution context.
int	getBudget() Determine the total amount of a memory under the control of this resource constraint instance.
static ThreadConstraint	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.
int	used() Determine how much of the resource have been used of the amount available.

Methods inherited from class javax.realtime.enforce.ResourceConstraint

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

Methods inherited from class java.lang.Object

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

Constructor Detail

ThreadConstraint

public ThreadConstraint(RealtimeThreadGroup group,
                        int max)
                 throws StaticIllegalStateException

Creates a ThreadConstraint to govern a group of threads.

Throws:

StaticIllegalStateException

Parameters:

group - The RealtimeThreadGroup to govern.

max - The maximum number of threads allowed.

Method Detail

getRootConstraint

public static ThreadConstraint getRootConstraint()

Get the root instance for this constraint type.

Returns:

the root constraint.

currentConstraint

public static ThreadConstraint currentConstraint()

Determine the processing constraint for the current execution context.

Returns:

the constraint for this context.

currentConstraint

public static ThreadConstraint currentConstraint(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 ThreadConstraint currentConstraint(ThreadGroup group)

Determine the processing 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<ThreadConstraint>

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<ThreadConstraint>

stop

public void stop()

Stop applying this constraint to is tasks.

Specified by:

stop in class ResourceConstraint<ThreadConstraint>

getBudget

public int 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 int used()

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

Returns:

the amount used in number of bytes.

available

public int 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.