com.netflix.curator.framework.recipes.locks
Class InterProcessSemaphoreMutex

java.lang.Object
  com.netflix.curator.framework.recipes.locks.InterProcessSemaphoreMutex

All Implemented Interfaces:

InterProcessLock

public class InterProcessSemaphoreMutex
extends java.lang.Object
implements InterProcessLock

A NON re-entrant mutex that works across JVMs. Uses Zookeeper to hold the lock. All processes in all JVMs that use the same lock path will achieve an inter-process critical section.

Constructor Summary

InterProcessSemaphoreMutex(com.netflix.curator.framework.CuratorFramework client, java.lang.String path)

Method Summary

void	acquire() Acquire the mutex - blocking until it's available.
boolean	acquire(long time, java.util.concurrent.TimeUnit unit) Acquire the mutex - blocks until it's available or the given time expires.
boolean	isAcquiredInThisProcess() Returns true if the mutex is acquired by a thread in this JVM
void	release() Perform one release of the mutex if the calling thread is the same thread that acquired it.

Methods inherited from class java.lang.Object

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

Constructor Detail

InterProcessSemaphoreMutex

public InterProcessSemaphoreMutex(com.netflix.curator.framework.CuratorFramework client,
                                  java.lang.String path)

Parameters:

client - the client

path - path for the lock

Method Detail

acquire

public void acquire()
             throws java.lang.Exception

Description copied from interface: InterProcessLock

Acquire the mutex - blocking until it's available. Note: the same thread can call acquire re-entrantly. Each call to acquire must be balanced by a call to InterProcessLock.release()

Specified by:

acquire in interface InterProcessLock

Throws:

java.lang.Exception - ZK errors, interruptions, another thread owns the lock

acquire

public boolean acquire(long time,
                       java.util.concurrent.TimeUnit unit)
                throws java.lang.Exception

Description copied from interface: InterProcessLock

Acquire the mutex - blocks until it's available or the given time expires. Note: the same thread can call acquire re-entrantly. Each call to acquire that returns true must be balanced by a call to InterProcessLock.release()

Specified by:

acquire in interface InterProcessLock

Parameters:

time - time to wait

unit - time unit

Returns:

true if the mutex was acquired, false if not

Throws:

java.lang.Exception - ZK errors, interruptions, another thread owns the lock

release

public void release()
             throws java.lang.Exception

Description copied from interface: InterProcessLock

Perform one release of the mutex if the calling thread is the same thread that acquired it. If the thread had made multiple calls to acquire, the mutex will still be held when this method returns.

Specified by:

release in interface InterProcessLock

Throws:

java.lang.Exception - ZK errors, interruptions, current thread does not own the lock

isAcquiredInThisProcess

public boolean isAcquiredInThisProcess()

Description copied from interface: InterProcessLock

Returns true if the mutex is acquired by a thread in this JVM

Specified by:

isAcquiredInThisProcess in interface InterProcessLock

Returns:

true/false