info.magnolia.cache.concurrent

Class ConcurrencyUtil

java.lang.Object

info.magnolia.cache.concurrent.ConcurrencyUtil

public final class ConcurrencyUtil
extends Object

Various bits of black magic garnered from experts on the concurrency-interest@cs.oswego.edu mailing list.

Version:

$Id: ConcurrencyUtil.java 7833 2013-07-25 01:00:20Z cschanck $

Author:

Greg Luck

Method Summary

Modifier and Type	Method and Description
static int	hash(Object object) Returns a hash code for non-null Object x.
static int	selectLock(Object key, int numberOfLocks) Selects a lock for a key.

Methods inherited from class java.lang.Object

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

Method Detail

hash

public static int hash(Object object)

Returns a hash code for non-null Object x.

This function ensures that hashCodes that differ only by constant multiples at each bit position have a bounded number of collisions. (Doug Lea)

Parameters:

object - the object serving as a key

Returns:

the hash code

selectLock

public static int selectLock(Object key,
                             int numberOfLocks)

Selects a lock for a key. The same lock is always used for a given key.

Parameters:

key -

Returns:

the selected lock index