edu.illinois.cs.cogcomp.wikifier.utils.concurrent

Class NamedLocks

java.lang.Object

edu.illinois.cs.cogcomp.wikifier.utils.concurrent.NamedLocks

public class NamedLocks
extends Object

Usage:

 NamedLocks locks = new NamedLocks(); 
 synchronized (locks.acquire(key)) { 
      // Synchronized for all locks named key 
 }
 

Keys must implement hashCode() and equals() correctly. Lock objects are weak references thus GCed once no longer reachable from code. You should not keep hard references to the acquired lock outside of the synchronized block.

Author:

cheng88

Constructor Summary

Constructors

Constructor and Description
NamedLocks() Constructs the lock holder.

Method Summary

Modifier and Type	Method and Description
Object	acquire(Object key) Acquires a lock for the specified key.
static void	lockOnce(String name)
int	size()
static void	unlockOnce(String name)

Methods inherited from class java.lang.Object

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

Constructor Detail

NamedLocks

public NamedLocks()

Constructs the lock holder.

Method Detail

acquire

public Object acquire(Object key)

Acquires a lock for the specified key.

Parameters:

key -

Returns:

the object to lock on for the key

size

public int size()

Returns:

Approximate size

lockOnce

public static void lockOnce(String name)

unlockOnce

public static void unlockOnce(String name)