org.apache.hadoop.hbase.util

Class KeyLocker<K>

java.lang.Object

org.apache.hadoop.hbase.util.KeyLocker<K>

@InterfaceAudience.Private
public class KeyLocker<K>
extends Object

A utility class to manage a set of locks. Each lock is identified by a String which serves as a key. Typical usage is:

 class Example {
   private final static KeyLocker<String> locker = new Locker<String>();
   public void foo(String s){
     Lock lock = locker.acquireLock(s);
     try {
       // whatever
     }finally{
       lock.unlock();
     }
   }
 }
 

Constructor Summary

Constructors

Constructor and Description
KeyLocker()

Method Summary

Modifier and Type	Method and Description
ReentrantLock	acquireLock(K key) Return a lock for the given key.
Map<K,Lock>	acquireLocks(Set<? extends K> keys) Acquire locks for a set of keys.

Methods inherited from class java.lang.Object

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

Constructor Detail

KeyLocker

public KeyLocker()

Method Detail

acquireLock

public ReentrantLock acquireLock(K key)

Return a lock for the given key. The lock is already locked.

Parameters:

key -

acquireLocks

public Map<K,Lock> acquireLocks(Set<? extends K> keys)

Acquire locks for a set of keys. The keys will be sorted internally to avoid possible deadlock.

Throws:

ClassCastException - if the given keys contains elements that are not mutually comparable