JNR 2023-06-06 · jnr.ffi.util.ref.internal.Finalizer

Thread that finalizes referents. All references should implement com.google.common.base.FinalizableReference.

While this class is public, we consider it to be *internal* and not part of our published API. It is public so we can access it reflectively across class loaders in secure environments.

This class can't depend on other Google Collections code. If we were to load this class in the same class loader as the rest of Google Collections, this thread would keep an indirect strong reference to the class loader and prevent it from being garbage collected. This poses a problem for environments where you want to throw away the class loader. For example, dynamically reloading a web application or unloading an OSGi bundle.

com.google.common.base.FinalizableReferenceQueue loads this class in its own class loader. That way, this class doesn't prevent the main class loader from getting garbage collected, and this class can detect when the main class loader has been garbage collected and stop itself.

Field Summary

Modifier and Type	Field and Description
private static final String	FINALIZABLE_REFERENCE Name of FinalizableReference.class.
private final WeakReference<Class<?>>	finalizableReferenceClassReference
private final PhantomReference<Object>	frqReference
private static final Field	inheritableThreadLocals
private static final Constructor<Thread>	inheritableThreadlocalsConstructor
private static final Logger	logger
private final ReferenceQueue<Object>	queue
private Thread	thread

Constructor Summary

Access	Constructor and Description
private	Finalizer(Class<?> finalizableReferenceClass, Object frq) Constructs a new finalizer thread.

Method Summary

Modifier and Type	Method and Description
private boolean	cleanUp(Reference<?> reference) Cleans up a single reference.
private Method	getFinalizeReferentMethod() Looks up FinalizableReference.finalizeReferent() method.
public static Constructor<Thread>	getInheritableThreadLocalsConstructor()
public static Field	getInheritableThreadLocalsField()
public void	run() Implements java.lang.Runnable.run. Loops continuously, pulling references off the queue and cleaning them up.
public void	start()
public static ReferenceQueue<Object>	Returns: ReferenceQueue which Finalizer will poll startFinalizer(Class<?> FinalizableReference.class finalizableReferenceClass, Object reference to instance of FinalizableReferenceQueue that started this thread frq) Starts the Finalizer thread.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

FINALIZABLE_REFERENCE	back to summary
private static final String FINALIZABLE_REFERENCE Name of FinalizableReference.class.

finalizableReferenceClassReference	back to summary
private final WeakReference<Class<?>> finalizableReferenceClassReference

frqReference	back to summary
private final PhantomReference<Object> frqReference

inheritableThreadLocals	back to summary
private static final Field inheritableThreadLocals

inheritableThreadlocalsConstructor	back to summary
private static final Constructor<Thread> inheritableThreadlocalsConstructor

logger	back to summary
private static final Logger logger

queue	back to summary
private final ReferenceQueue<Object> queue

thread	back to summary
private Thread thread

Constructor Detail

Finalizer	back to summary
private Finalizer(Class<?> finalizableReferenceClass, Object frq) Constructs a new finalizer thread.

Method Detail

cleanUp	back to summary
private boolean cleanUp(Reference<?> reference) Cleans up a single reference. Catches and logs all throwables.

getFinalizeReferentMethod	back to summary
private Method getFinalizeReferentMethod() Looks up FinalizableReference.finalizeReferent() method.

getInheritableThreadLocalsConstructor	back to summary
public static Constructor<Thread> getInheritableThreadLocalsConstructor()

getInheritableThreadLocalsField	back to summary
public static Field getInheritableThreadLocalsField()

run	back to summary
public void run() Implements java.lang.Runnable.run. Loops continuously, pulling references off the queue and cleaning them up. Annotations @SuppressWarnings:InfiniteLoopStatement @Override

run

back to summary

public void run()

Implements java.lang.Runnable.run.

Loops continuously, pulling references off the queue and cleaning them up.

Annotations

@SuppressWarnings:InfiniteLoopStatement
@Override

start	back to summary
public void start()

startFinalizer	back to summary
public static ReferenceQueue<Object> startFinalizer(Class<?> finalizableReferenceClass, Object frq) Starts the Finalizer thread. FinalizableReferenceQueue calls this method reflectively. Parameters finalizableReferenceClass:Class<?> FinalizableReference.class frq:Object reference to instance of FinalizableReferenceQueue that started this thread Returns:ReferenceQueue<Object> ReferenceQueue which Finalizer will poll

startFinalizer

back to summary

public static ReferenceQueue<Object> startFinalizer(Class<?> finalizableReferenceClass, Object frq)

Starts the Finalizer thread. FinalizableReferenceQueue calls this method reflectively.

Parameters

finalizableReferenceClass:Class<?>: FinalizableReference.class
frq:Object: reference to instance of FinalizableReferenceQueue that started this thread

Returns:ReferenceQueue<Object>