Package com.identityworksllc.iiq.common.threads

Class LockingObjectReference<T>

java.lang.Object

com.identityworksllc.iiq.common.threads.LockingObjectReference<T>

Type Parameters:

T - The type of the contained object

All Implemented Interfaces:

AutoCloseable

public final class LockingObjectReference<T>
extends Object
implements AutoCloseable

An object reference wrapped by a ReentrantLock.

This allows either directly invoking a function on the locked object or a more procedural lock/unlock pattern. This is fairer and safer than synchronizing on the object, since it can be interrupted (via Thread.interrupt(), e.g. on a task termination) and fairly chooses the longest-waiting thread to execute next.

In either usage, threads will wait forever for the lock. Threads will emit an INFO level log message every 30 seconds indicating that they are still waiting. Additionally, threads will emit a DEBUG message upon acquiring the lock. Both messages will have a UUID indicating a unique lock name, for tracing purposes.

If you are calling this from Beanshell, you can directly pass the name of a Beanshell method, along with the ‘this’ reference, such as:

objReference.lockAndAct(this, “beanshellMethodName”);

On lock acquisition, the specified Beanshell method in the ‘this’ scope will be invoked, passing the object as the only argument. The object will be automatically freed after the method completes.

You can also use this class via a try/finally structure, such as:

Object lockedObject = objReference.lock(); try { // do stuff here } finally { objReference.unlock(); }

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	LockingObjectReference.LockedObjectAction<T>	The interface to be implemented by any locked object actions

Constructor Summary

Constructors

Constructor	Description
LockingObjectReference(T object)

Method Summary

Modifier and Type	Method	Description
void	close()	Unlocks the object, allowing use of this class in a try-with-resources context
void	lockAndAct(bsh.This beanshell, String methodName)	Locks the object, then passes it to the given Beanshell method.
void	lockAndAct(LockingObjectReference.LockedObjectAction<T> action)	Locks the object, then passes it to LockingObjectReference.LockedObjectAction.accept(Object).
T	lockObject()	Locks the object (waiting forever if necessary), then returns the object
void	unlockObject()	Unlocks the object

Methods inherited from class java.lang.Object

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

Constructor Detail

LockingObjectReference

public LockingObjectReference(T object)

Method Detail

close

public void close()

Unlocks the object, allowing use of this class in a try-with-resources context

Specified by:

close in interface AutoCloseable

lockAndAct

public void lockAndAct(LockingObjectReference.LockedObjectAction<T> action)
                throws sailpoint.tools.GeneralException

Locks the object, then passes it to LockingObjectReference.LockedObjectAction.accept(Object).

Parameters:

action - The function to execute against the object after it is locked

Throws:

sailpoint.tools.GeneralException - if any failures occur

lockAndAct

public void lockAndAct(bsh.This beanshell,
                       String methodName)
                throws sailpoint.tools.GeneralException

Locks the object, then passes it to the given Beanshell method.

Parameters:

beanshell - The Beanshell context (‘this’ in a script)

methodName - The name of a Beanshell method in the current ‘this’ context or a parent

Throws:

sailpoint.tools.GeneralException - if any failures occur

lockObject

public T lockObject()
             throws sailpoint.tools.GeneralException

Locks the object (waiting forever if necessary), then returns the object

Returns:

The object, now exclusive to this thread

Throws:

sailpoint.tools.GeneralException - if any failures occur

unlockObject

public void unlockObject()

Unlocks the object