org.adroitlogic.x.base.util

Class SingleInstanceLockManager

java.lang.Object

org.adroitlogic.x.base.util.SingleInstanceLockManager

public class SingleInstanceLockManager
extends Object

This is a utility class to facilitate to get locks which can be either Semaphore based or ReentrantLock based to facilitate synchronization. This will give the sequence number generating functionality as well. This will only be useful for VM level locks or sequence numbers which won't be applicable for clustered deployment

Since:

17.01

Author:

Manjula Piyumal, Dimuthu Upeksha

Constructor Summary

Constructors

Constructor and Description
SingleInstanceLockManager()

Method Summary

Modifier and Type	Method and Description
static SingleInstanceLockManager	getInstance()
Optional<Integer>	getNextSequenceNumber(String keyPath) Generate the next sequence number for the given keyPath
boolean	isAcquired(String lockPath) Checks whether a Semaphore based lock is acquired
void	releaseLock(String lockPath) Releases the acquired Semaphore based lock for the given lockPath
void	releaseReentrantLock(String lockPath) Release the acquired ReentrantLock for the given lockPath
boolean	tryLock(String lockPath) Attempts to get a Semaphore based lock for the given lockPath.
boolean	tryLock(String lockPath, long timeout) Attempts to get a Semaphore based lock for the given lockPath within the given timeout value.
boolean	tryReentrantLock(String lockPath) Attempts to get a ReentrantLock lock for the given lockPath which will be useful only for acquire and release using the same thread.

Methods inherited from class java.lang.Object

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

Constructor Detail

SingleInstanceLockManager

public SingleInstanceLockManager()

Method Detail

getInstance

public static SingleInstanceLockManager getInstance()

getNextSequenceNumber

public Optional<Integer> getNextSequenceNumber(String keyPath)

Generate the next sequence number for the given keyPath

Parameters:

keyPath - the key to associate the sequence number

Returns:

the next generated sequence number for the given keyPath

tryReentrantLock

public boolean tryReentrantLock(String lockPath)

Attempts to get a ReentrantLock lock for the given lockPath which will be useful only for acquire and release using the same thread. If it's going to acquire the lock from one thread and release from anther thread, then this API won't help to facilitate the required synchronization. For those type of scenarios instead of this, use the tryLock() API

Parameters:

lockPath - the key to get the ReentrantLock

Returns:

true if it's able to get acquire the lock for the given path, false otherwise

releaseReentrantLock

public void releaseReentrantLock(String lockPath)

Release the acquired ReentrantLock for the given lockPath

Parameters:

lockPath - the key to find the lock which should be acquired before

tryLock

public boolean tryLock(String lockPath)

Attempts to get a Semaphore based lock for the given lockPath. In this method, it's not required to acquire and release the lock using the same thread

Parameters:

lockPath - the key to get the Semaphore

Returns:

true if it's able to get acquire the lock for the given path, false otherwise

tryLock

public boolean tryLock(String lockPath,
                       long timeout)

Attempts to get a Semaphore based lock for the given lockPath within the given timeout value. In this method, it's not required to acquire and release the lock using the same thread.

Parameters:

lockPath - the key to get the Semaphore

timeout - maximum time in milliseconds that should wait trying to acquire the lock

Returns:

true if it's able to get acquire the lock for the given path and within given timeout, false otherwise

isAcquired

public boolean isAcquired(String lockPath)

Checks whether a Semaphore based lock is acquired

Parameters:

lockPath - the key to find the Semaphore that is related to this lock

Returns:

true if the lock is acquired, false otherwise

releaseLock

public void releaseLock(String lockPath)

Releases the acquired Semaphore based lock for the given lockPath

Parameters:

lockPath - the key to find the lock which should be acquired before