Package org.apache.bookkeeper.common.util

Class SharedResourceManager

java.lang.Object

org.apache.bookkeeper.common.util.SharedResourceManager

public class SharedResourceManager
extends Object

A holder for shared resource singletons.

Components like clients and servers need certain resources, e.g. a scheduler, to run. If the user has not provided such resources, these components will use a default one, which is shared as a static resource. This class holds these default resources and manages their lifecycles.

A resource is identified by the reference of a SharedResourceManager.Resource object, which is typically a singleton, provided to the get() and release() methods. Each resource object (not its class) maps to an object cached in the holder.

Resources are ref-counted and shut down after a delay when the refcount reaches zero.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	SharedResourceManager.Resource<T>	Defines a resource, and the way to create and destroy instances of it.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) static final long	DESTROY_DELAY_SECONDS

Method Summary

Modifier and Type	Method	Description
static SharedResourceManager	create()
static SharedResourceManager	create(Supplier<ScheduledExecutorService> destroyerFactory)
<T> T	get(SharedResourceManager.Resource<T> resource)
<T> void	release(SharedResourceManager.Resource<T> resource, T instance)
static SharedResourceManager	shared()

Methods inherited from class java.lang.Object

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

Field Details

DESTROY_DELAY_SECONDS

static final long DESTROY_DELAY_SECONDS

See Also:

• Constant Field Values

Method Details

shared

public static SharedResourceManager shared()

create

public static SharedResourceManager create()

create

public static SharedResourceManager create(Supplier<ScheduledExecutorService> destroyerFactory)

get

public <T> T get(SharedResourceManager.Resource<T> resource)

release

public <T> void release(SharedResourceManager.Resource<T> resource,
 T instance)