Class DefaultDestructorTree

java.lang.Object

org.microbean.reference.DefaultDestructorTree

All Implemented Interfaces:

AutoCloseable, DestructorRegistry, DestructorTree

public class DefaultDestructorTree
extends Object
implements DestructorTree

A straightforward DestructorTree implementation.

Author:

Laird Nelson

See Also:

• DestructorTree

Nested Class Summary

Nested classes/interfaces inherited from interface org.microbean.reference.DestructorRegistry

DestructorRegistry.Destructor

Constructor Summary

Constructors

Constructor	Description
DefaultDestructorTree()	Creates a new DefaultDestructorTree.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes this DefaultDestructorTree and destroys its registrants by running their destructors supplied at registration time.
DefaultDestructorTree	newChild()	Creates a new child instance of this implementation, or a subtype, registers it with this implementation, using a method reference to its DestructorTree.close() method as the DestructorRegistry.Destructor, and returns it.
final boolean	register(Object reference, DestructorRegistry.Destructor destructor)	If this DefaultDestructorTree is not closed, and if the supplied reference has not yet been registered, registers it such that it will be destroyed by the supplied destructor when this DefaultDestructorTree is closed, and returns true.
final DestructorRegistry.Destructor	remove(Object reference)	Removes the supplied contextual instance and the DestructorRegistry.Destructor that was registered with it.

Methods inherited from class java.lang.Object

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

Constructor Details

DefaultDestructorTree

public DefaultDestructorTree()

Creates a new DefaultDestructorTree.

Method Details

newChild

public DefaultDestructorTree newChild()

Description copied from interface: DestructorTree

Creates a new child instance of this implementation, or a subtype, registers it with this implementation, using a method reference to its DestructorTree.close() method as the DestructorRegistry.Destructor, and returns it.

Specified by:

newChild in interface DestructorTree

Returns:

a new (non-null) child instance of this implementation, or a subtype, registered with this implementation such that closing this implementation will also close the child instance

See Also:

• DestructorTree.close()
• DestructorRegistry.register(Object, Destructor)

close

public void close()

Closes this DefaultDestructorTree and destroys its registrants by running their destructors supplied at registration time.

DestructorRegistry.Destructor.destroy() is called on all registrants, even in the presence of exceptions. RuntimeExceptions consequently thrown may contain suppressed exceptions.

Overrides of this method wishing to add semantics to this behavior should perform that work before calling super.close().

Overrides of this method must call super.close() or undefined behavior may result.

After any successful invocation of this method, this DefaultDestructorTree is deemed to be irrevocably closed. Invoking this method again will have no effect.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface DestructorTree

See Also:

• DestructorTree.remove(Object)

Idempotency:

This method is, and its overrides must be, idempotent.

Thread Safety:

This method is, and its overrides must be, safe for concurrent use by multiple threads.

register

public final boolean register(Object reference,
 DestructorRegistry.Destructor destructor)

If this DefaultDestructorTree is not closed, and if the supplied reference has not yet been registered, registers it such that it will be destroyed by the supplied destructor when this DefaultDestructorTree is closed, and returns true.

This method takes no action and returns false in all other cases.

Specified by:

register in interface DestructorRegistry

Parameters:

reference - a contextual reference that will be destroyed later; if null then no action will be taken and false will be returned

destructor - a DestructorRegistry.Destructor that, when run, will destroy the supplied reference in some way; if null then no action will be taken and false will be returned; if non-null must be idempotent and safe for concurrent use by multiple threads

Returns:

true if and only if this DefaultDestructorTree is not closed, and the supplied reference is not already registered and registration completed successfully; false in all other cases

See Also:

• DestructorRegistry.Destructor

Idempotency:

This method is idempotent.

Thread Safety:

This method is safe for concurrent use by multiple threads.

remove

public final DestructorRegistry.Destructor remove(Object reference)

Description copied from interface: DestructorTree

Removes the supplied contextual instance and the DestructorRegistry.Destructor that was registered with it.

The DestructorRegistry.Destructor.destroy() will not be invoked by implementations of this method.

Specified by:

remove in interface DestructorTree

Parameters:

reference - the contextual instance to remove; may be null in which case null will be returned

Returns:

a DestructorRegistry.Destructor registered with the supplied instance, or null if no such DestructorRegistry.Destructor exists