edu.umass.cs.utils

Class StringLocker

java.lang.Object

edu.umass.cs.utils.StringLocker

public class StringLocker
extends java.lang.Object

Author:

V. Arun This class is a hack in order to have the syntactic luxury of saying synchronized(key), for an arbitrary String key, and get synchronization with respect to anyone else competing also for a synchronized(key) code block. Normally, we don't get this property, i.e., synchronization on key1 and key2 are unrelated even if key1.equals(key2). With this class, the caller can simply say synchronized(stringLocker.get(key)) { ... } and ensure synchronization for the following code block with respect to anyone else also using the same stringLocker object. We need to be careful to rely on this only when we know that the total number of Strings used for synchronization will be small. It is best to use this class only for constant strings.

Constructor Summary

Constructors

Constructor and Description
StringLocker()

Method Summary

Modifier and Type	Method and Description
java.lang.String	get(java.lang.String key)
void	remove(java.lang.String key) Removes key when no one is using it for synchronization.

Methods inherited from class java.lang.Object

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

Constructor Detail

StringLocker

public StringLocker()

Method Detail

get

public java.lang.String get(java.lang.String key)

Parameters:

key -

Returns:

The canonical String that equals key.

remove

public void remove(java.lang.String key)

Removes key when no one is using it for synchronization. We know that no one is using it because we are using it ourselves through the synchronized(get(key) block below.

Parameters:

key -