public class Finalizer
extends java.lang.Object
implements java.lang.Runnable
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 Guava code. If we were to load this class in the same class loader as the rest of Guava, 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.
Modifier and Type | Field and Description |
---|---|
private static java.lang.reflect.Constructor<java.lang.Thread> |
bigThreadConstructor |
private static java.lang.String |
FINALIZABLE_REFERENCE
Name of FinalizableReference.class.
|
private java.lang.ref.WeakReference<java.lang.Class<?>> |
finalizableReferenceClassReference |
private java.lang.ref.PhantomReference<java.lang.Object> |
frqReference |
private static java.lang.reflect.Field |
inheritableThreadLocals |
private static java.util.logging.Logger |
logger |
private java.lang.ref.ReferenceQueue<java.lang.Object> |
queue |
Modifier | Constructor and Description |
---|---|
private |
Finalizer(java.lang.Class<?> finalizableReferenceClass,
java.lang.ref.ReferenceQueue<java.lang.Object> queue,
java.lang.ref.PhantomReference<java.lang.Object> frqReference)
Constructs a new finalizer thread.
|
Modifier and Type | Method and Description |
---|---|
private boolean |
cleanUp(java.lang.ref.Reference<?> reference)
Cleans up a single reference.
|
private static java.lang.reflect.Constructor<java.lang.Thread> |
getBigThreadConstructor() |
private java.lang.reflect.Method |
getFinalizeReferentMethod()
Looks up FinalizableReference.finalizeReferent() method.
|
private static java.lang.reflect.Field |
getInheritableThreadLocalsField() |
void |
run()
Loops continuously, pulling references off the queue and cleaning them up.
|
static void |
startFinalizer(java.lang.Class<?> finalizableReferenceClass,
java.lang.ref.ReferenceQueue<java.lang.Object> queue,
java.lang.ref.PhantomReference<java.lang.Object> frqReference)
Starts the Finalizer thread.
|
private static final java.util.logging.Logger logger
private static final java.lang.String FINALIZABLE_REFERENCE
private final java.lang.ref.WeakReference<java.lang.Class<?>> finalizableReferenceClassReference
private final java.lang.ref.PhantomReference<java.lang.Object> frqReference
private final java.lang.ref.ReferenceQueue<java.lang.Object> queue
private static final java.lang.reflect.Constructor<java.lang.Thread> bigThreadConstructor
private static final java.lang.reflect.Field inheritableThreadLocals
private Finalizer(java.lang.Class<?> finalizableReferenceClass, java.lang.ref.ReferenceQueue<java.lang.Object> queue, java.lang.ref.PhantomReference<java.lang.Object> frqReference)
public static void startFinalizer(java.lang.Class<?> finalizableReferenceClass, java.lang.ref.ReferenceQueue<java.lang.Object> queue, java.lang.ref.PhantomReference<java.lang.Object> frqReference)
finalizableReferenceClass
- FinalizableReference.class.queue
- a reference queue that the thread will poll.frqReference
- a phantom reference to the FinalizableReferenceQueue, which will be queued
either when the FinalizableReferenceQueue is no longer referenced anywhere, or when its
close() method is called.public void run()
run
in interface java.lang.Runnable
private boolean cleanUp(java.lang.ref.Reference<?> reference)
private java.lang.reflect.Method getFinalizeReferentMethod()
private static java.lang.reflect.Field getInheritableThreadLocalsField()
private static java.lang.reflect.Constructor<java.lang.Thread> getBigThreadConstructor()