Package com.ibm.icu.impl.coll

Class SharedObject.Reference<T extends SharedObject>

  • All Implemented Interfaces:
    Cloneable
    Enclosing class:
    SharedObject
    public static final class SharedObject.Reference<T extends SharedObject>
extends Object
implements Cloneable
    Similar to a smart pointer, basically a port of the static methods of C++ SharedObject.

    • Constructor Detail

      • Reference

        public Reference​(T r)

    • Method Detail

      • clone

        public SharedObject.Reference<T> clone()
        Description copied from class: Object
        Creates and returns a copy of this Object. The default implementation returns a so-called "shallow" copy: It creates a new instance of the same class and then copies the field values (including object references) from this instance to the new instance. A "deep" copy, in contrast, would also recursively clone nested objects. A subclass that needs to implement this kind of cloning should call super.clone() to create the new instance and then create deep copies of the nested, mutable objects.
        Overrides:
        clone in class Object
        Returns:
        a copy of this object.

      • readOnly

        public T readOnly()

      • copyOnWrite

        public T copyOnWrite()
        Returns a writable version of the reference. If there is exactly one owner, then the reference itself is returned. If there are multiple owners, then the reference is replaced with a clone, and that is returned.

      • clear

        public void clear()

      • finalize

        protected void finalize()
                 throws Throwable
        Description copied from class: Object
        Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.

        Note that objects that override finalize are significantly more expensive than objects that don't. Finalizers may be run a long time after the object is no longer reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup. Note also that finalizers are run on a single VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary for a class that has a native peer and needs to call a native method to destroy that peer. Even then, it's better to provide an explicit close method (and implement Closeable), and insist that callers manually dispose of instances. This works well for something like files, but less well for something like a BigInteger where typical calling code would have to deal with lots of temporaries. Unfortunately, code that creates lots of temporaries is the worst kind of code from the point of view of the single finalizer thread.

        If you must use finalizers, consider at least providing your own ReferenceQueue and having your own thread process that queue.

        Unlike constructors, finalizers are not automatically chained. You are responsible for calling super.finalize() yourself.

        Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.

        Overrides:
        finalize in class Object
        Throws:
        Throwable