org.eclipse.gemini.blueprint.extender.internal.support

Class LazyBundleRegistry<T>

java.lang.Object

org.eclipse.gemini.blueprint.extender.internal.support.LazyBundleRegistry<T>

Type Parameters:

T - the entity type associated with active bundles

class LazyBundleRegistry<T>
extends java.lang.Object

Map-like class with dedicated support for lazy bundles. Allows execution of operations on active bundles, promoting the lazy ones, if necessary, as fall back. The class is thread-safe.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static interface	LazyBundleRegistry.Activator<V> Activator action performed on lazy bundles upon promotion.
(package private) static interface	LazyBundleRegistry.Condition A simple condition-like class.
(package private) static interface	LazyBundleRegistry.Operation<T,V> Operation performed all bundles - first active ones, followed by lazy ones (if nothing is found (null is returned)) by 'activating' them.

Field Summary

Fields

Modifier and Type	Field and Description
private LazyBundleRegistry.Activator<T>	activator
private java.util.concurrent.ConcurrentMap<org.osgi.framework.Bundle,T>	activeBundles active, valid bundles
private LazyBundleRegistry.Condition	condition
private java.util.concurrent.ConcurrentMap<org.osgi.framework.Bundle,java.lang.Boolean>	lazyBundles lazy bundles (potentially invalid)
private org.apache.commons.logging.Log	log logger
private java.util.List<org.osgi.framework.Bundle>	promotionQueue Queue of bundles that have been activated and validated and should be removed from the lazy map.
private java.util.concurrent.atomic.AtomicInteger	threadCounter counter used for determining the promotion thread

Constructor Summary

Constructors

Constructor and Description
LazyBundleRegistry(LazyBundleRegistry.Condition promotionCondition, LazyBundleRegistry.Activator<T> activator, org.apache.commons.logging.Log log)

Method Summary

Modifier and Type	Method and Description
(package private) void	add(org.osgi.framework.Bundle bundle, boolean isLazy, boolean applyCondition)
(package private) <V> V	apply(LazyBundleRegistry.Operation<T,V> action) Applies an operation on all the bundles.
void	clear()
(package private) boolean	remove(org.osgi.framework.Bundle bundle)

Methods inherited from class java.lang.Object

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

Field Detail

log

private final org.apache.commons.logging.Log log

logger

activeBundles

private final java.util.concurrent.ConcurrentMap<org.osgi.framework.Bundle,T> activeBundles

active, valid bundles

lazyBundles

private final java.util.concurrent.ConcurrentMap<org.osgi.framework.Bundle,java.lang.Boolean> lazyBundles

lazy bundles (potentially invalid)

promotionQueue

private final java.util.List<org.osgi.framework.Bundle> promotionQueue

Queue of bundles that have been activated and validated and should be removed from the lazy map. This is needed so that promoted bundles do not go unseen by threads using the method at that point.

threadCounter

private volatile java.util.concurrent.atomic.AtomicInteger threadCounter

counter used for determining the promotion thread

condition

private final LazyBundleRegistry.Condition condition

activator

private final LazyBundleRegistry.Activator<T> activator

Constructor Detail

LazyBundleRegistry

LazyBundleRegistry(LazyBundleRegistry.Condition promotionCondition,
                   LazyBundleRegistry.Activator<T> activator,
                   org.apache.commons.logging.Log log)

Method Detail

add

void add(org.osgi.framework.Bundle bundle,
         boolean isLazy,
         boolean applyCondition)

remove

boolean remove(org.osgi.framework.Bundle bundle)

apply

<V> V apply(LazyBundleRegistry.Operation<T,V> action)
     throws java.lang.Exception

Applies an operation on all the bundles. To cope with concurrent environment, the class uses several queues so that lazy bundles that get activated, do not get ignored by threads hitting the method right at that point.

Type Parameters:

V -

Parameters:

action -

Returns:

Throws:

java.lang.Exception

clear

public void clear()