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() Gets the number of threads that still may be created.
static ThreadConstraint	currentConstraint() Determine the processing constraint for the current execution context.
static ThreadConstraint	currentConstraint(java.lang.Thread thread) Determine the processing constraint for the give execution context.
static ThreadConstraint	currentConstraint(java.lang.ThreadGroup group) Determine the thread constraint for the give execution context.
int	getBudget() Get the number of threads that may be created in this group.
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() Gets the cost used in the current period so far.

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

ThreadConstraint

public ThreadConstraint(RealtimeThreadGroup group,
                        int max)

Creates a ThreadConstraint to govern a group of threads.

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(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 ThreadConstraint currentConstraint(java.lang.ThreadGroup group)

Determine the thread 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()

Get the number of threads that may be created in this group. The limit takes effect on start.

Returns:

The limit of threads that can be created.

used

public int used()

Gets the cost used in the current period so far.

Returns:

an new object containing the cost used in the current period.

available

public int available()

Gets the number of threads that still may be created.

Returns:

the cost lent in an new object.