org.hawkular.metrics.api.jaxrs

Class DistributedLock

java.lang.Object

org.hawkular.metrics.api.jaxrs.DistributedLock

public class DistributedLock
extends Object

This is a lock implementation built on top of an Infinispan replicated/distributed cache. If the cache is local, the the methods in this class are basically no-ops. Note that the locking implementation is process-wide.

Author:

jsanda

Field Summary

Fields

Modifier and Type	Field and Description
static long	DEFAULT_RETRY_DELAY

Constructor Summary

Constructors

Constructor and Description
DistributedLock(org.infinispan.AdvancedCache<String,String> locksCache, String key)

Method Summary

Modifier and Type	Method and Description
boolean	lock() Returns true if the cache is local; otherwise, return true if the lock is acquired.
void	lockAndThen(long retryDelay, Runnable runnable) Blocks until the lock is acquired and then execute runnable.
void	lockAndThen(Runnable runnable) Blocks until the lock is acquired and then execute runnable.
boolean	release() Returns true if the cache is local.
void	viewChanged(org.infinispan.notifications.cachemanagerlistener.event.ViewChangedEvent event)

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_RETRY_DELAY

public static final long DEFAULT_RETRY_DELAY

See Also:

Constant Field Values

Constructor Detail

DistributedLock

public DistributedLock(org.infinispan.AdvancedCache<String,String> locksCache,
                       String key)

Parameters:

locksCache - The cache used for locking. This class will probably refactored at some point so that the cache can be directly injected.

key - The name or value of the lock.

Method Detail

lock

public boolean lock()

Returns true if the cache is local; otherwise, return true if the lock is acquired. The lock is held indefinitely until either release() is called or the owning process goes down. If the owner goes down, the rest of the cluster will clear the lock such that other cluster members can acquire it.

release

public boolean release()

Returns true if the cache is local. Returns true if this node owns the lock and is able to remove it from the cache.

lockAndThen

public void lockAndThen(Runnable runnable)

Blocks until the lock is acquired and then execute runnable. After runnable finishes, the lock is released. There is a delay of DEFAULT_RETRY_DELAY ms between successive attempts at acquiring the lock.

lockAndThen

public void lockAndThen(long retryDelay,
                        Runnable runnable)

Blocks until the lock is acquired and then execute runnable. After runnable finishes, the lock is released. There is a delay of retryDelay ms between successive attempts at acquiring the lock.

viewChanged

public void viewChanged(org.infinispan.notifications.cachemanagerlistener.event.ViewChangedEvent event)