Package org.xnio

Class AutomaticReference<T>

java.lang.Object
java.lang.ref.Reference<T>
java.lang.ref.PhantomReference<T>
org.xnio.AutomaticReference<T>
@Deprecated public abstract class AutomaticReference<T> extends PhantomReference<T>
Deprecated.
See CleanerReference.
An automatic reference is a phantom reference which is automatically freed by a background thread when it is enqueued. Since this type of garbage collection imposes considerable overhead, it should only be used sparingly, when it is impossible to achieve correctness any other way.
Author:
David M. Lloyd

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    AutomaticReference(T referent, Object permit)
    Deprecated.
    Construct a new instance.

  • Method Summary

    Modifier and Type
    Method
    Description
    final void
    clear()
    Deprecated.
    Not supported.
    final boolean
    enqueue()
    Deprecated.
    Not supported.
    protected abstract void
    free()
    Deprecated.
    Free this reference.
    final T
    get()
    Deprecated.
    Always returns null.
    static Object
    getPermit()
    Deprecated.
    Get the security authorization permit to create automatic references.
    final boolean
    isEnqueued()
    Deprecated.
    Determine whether this reference has been enqueued by the garbage collector.

    Methods inherited from class java.lang.ref.Reference

    clone, reachabilityFence, refersTo

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • AutomaticReference

      protected AutomaticReference(T referent, Object permit)
      Deprecated.
      Construct a new instance. In order to maximize performance, the only security check performed by this constructor is to verify the permit which was passed in.
      Parameters:
      referent - the object to monitor
      permit - the permit object originally acquired from getPermit()

  • Method Details

    • getPermit

      public static Object getPermit()
      Deprecated.
      Get the security authorization permit to create automatic references.
      Returns:
      the permit
      Throws:
      SecurityException - if a security manager is enabled and the caller does not have the createAutomaticReference RuntimePermission

    • get

      public final T get()
      Deprecated.
      Always returns null.
      Overrides:
      get in class PhantomReference<T>
      Returns:
      null

    • clear

      public final void clear()
      Deprecated.
      Not supported.
      Overrides:
      clear in class Reference<T>
      Throws:
      UnsupportedOperationException - always

    • isEnqueued

      public final boolean isEnqueued()
      Deprecated.
      Determine whether this reference has been enqueued by the garbage collector.
      Overrides:
      isEnqueued in class Reference<T>
      Returns:
      true if the reference has been enqueued, false otherwise

    • enqueue

      public final boolean enqueue()
      Deprecated.
      Not supported.
      Overrides:
      enqueue in class Reference<T>
      Returns:
      nothing
      Throws:
      UnsupportedOperationException - always

    • free

      protected abstract void free()
      Deprecated.
      Free this reference. This method will be called from a dedicated thread or threads so this method should execute as quickly as possible.