jdk.management.resource

Class NotifyingMeter

java.lang.Object

jdk.management.resource.SimpleMeter

jdk.management.resource.NotifyingMeter

All Implemented Interfaces:

ResourceMeter, ResourceRequest

Direct Known Subclasses:

BoundedMeter, ThrottledMeter

public class NotifyingMeter
extends SimpleMeter

A NotifyingMeter provides an approver callback for changes and allocates from an optional parent. The granularity applies only to the approval callback, the amount requested or freed is the same as the amount requested. The granularity may be set at any time. Approval callbacks occur upon crossing the granularity threshold for either allocations or releases. The callback can return the amount requested or zero to indicate the request is denied. Most applications are not resilient to changes to the size of I/O operations or availability of resources.

Since:

8u40

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	NotifyingMeter(ResourceType type, ResourceRequest parent, ResourceApprover approver) Constructor for subclasses.

Method Summary

Modifier and Type	Method and Description
static NotifyingMeter	create(ResourceType type, ResourceApprover approver) Returns a new NotifyingMeter with the type and approver.
static NotifyingMeter	create(ResourceType type, ResourceRequest parent, ResourceApprover approver) Returns a new NotifyingMeter with the type, approver and parent approver.
ResourceApprover	getApprover() Return the ResourceApprover.
long	getGranularity() Returns the granularity.
long	setGranularity(long granularity) Sets the granularity.
protected long	validate(long previous, long amount, ResourceId id) Returns the amount validated by the approver.

Methods inherited from class jdk.management.resource.SimpleMeter

create, create, equals, getAllocated, getParent, getType, getValue, hashCode, request, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

NotifyingMeter

protected NotifyingMeter(ResourceType type,
                         ResourceRequest parent,
                         ResourceApprover approver)

Constructor for subclasses. The granularity is initialized to 1.

Parameters:

type - the ResourceType

parent - a ResourceRequest to request from; may be null

approver - the ResourceApprover to be notified; may be null

Method Detail

create

public static NotifyingMeter create(ResourceType type,
                                    ResourceApprover approver)

Returns a new NotifyingMeter with the type and approver. The granularity is initialized to 1.

Parameters:

type - the ResourceType

approver - the ResourceApprover to be notified; may be null

Returns:

a new NotifyingMeter with the type and notify

create

public static NotifyingMeter create(ResourceType type,
                                    ResourceRequest parent,
                                    ResourceApprover approver)

Returns a new NotifyingMeter with the type, approver and parent approver. The granularity is initialized to 1.

Parameters:

type - the ResourceType

approver - the ResourceApprover to notify; may be null

parent - a ResourceRequest to request from; may be null

Returns:

a new NotifyingMeter with the type, notify, and parent approver

validate

protected long validate(long previous,
                        long amount,
                        ResourceId id)

Returns the amount validated by the approver. The ResourceApprover.request must return only the amount requested, zero, or throw a ResourceRequestDeniedException. If the amount returned is any other value, it is ignored and the requested amount is returned.

Overrides:

validate in class SimpleMeter

Parameters:

previous - the previous meter value

amount - the amount to validate; if zero nothing is done

id - the ResourceId for the resource instance; may be null

Returns:

the value validated zero, positive or negative

getGranularity

public final long getGranularity()

Returns the granularity.

Returns:

the granularity

setGranularity

public final long setGranularity(long granularity)

Sets the granularity.

Parameters:

granularity - Sets the granularity; the granularity must be greater than zero

Returns:

the previous granularity value

Throws:

IllegalArgumentException - if the granularity is less than or equal to zero

getApprover

public final ResourceApprover getApprover()

Return the ResourceApprover.

Returns:

the approver