shared

Class SharedObjectFactory

java.lang.Object

shared.SharedObjectFactory

public class SharedObjectFactory
extends Object

The SharedObjectsFactory is a 'weak' constant pool for uniquely represented objects.

This class is fully thread-safe, but tries to avoid (contended) locking as much as is reasonably achievable. As a result this implementation should scale fairly well on multi-core / processor systems; while also limiting synchronization overhead.

WARNING: Do not edit this class unless you fully understand both Java's memory and threading model and how the garbage collector(s) work. (You'll almost certainly 'break' something otherwise).
The JMM spec (previously known as JSR-133) can be found here: http://java.sun.com/docs/books/jls/third_edition/html/memory.html
Even experts should be cautious. Every line of code is in a certain place for a reason. Modifying anything may break thread-safety and / or can have a serious impact on performance.

Author:

Arnold Lankamp

Constructor Summary

Constructors

Constructor and Description
SharedObjectFactory() Default constructor.
SharedObjectFactory(int initialLogSize) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
SharedObject	build(SharedObject prototype) Finds or creates the unique version of the given shared object prototype.
void	cleanup() Removes stale entries from the set.
boolean	contains(SharedObject object) Checks if the given shared object is present in this factory.
String	toString() Returns statistics.

Methods inherited from class java.lang.Object

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

Constructor Detail

SharedObjectFactory

public SharedObjectFactory()

Default constructor.

SharedObjectFactory

public SharedObjectFactory(int initialLogSize)

Constructor. This is only here for backwards compatibility. The user shouldn't specify the logsize, we'll resize the table ourselfs when needed.

Parameters:

initialLogSize - This is the argument that will be ignored.

Method Detail

cleanup

public void cleanup()

Removes stale entries from the set.

toString

public String toString()

Returns statistics.

Overrides:

toString in class Object

See Also:

Object.toString()

build

public SharedObject build(SharedObject prototype)

Finds or creates the unique version of the given shared object prototype.

Parameters:

prototype - The prototype of the shared object we want the unique reference too.

Returns:

The reference to the unique shared object associated with the argument.

contains

public boolean contains(SharedObject object)

Checks if the given shared object is present in this factory.

Parameters:

prototype - The shared object.

Returns:

True if this factory contains the given shared object; false otherwise.