io.fabric8.utils

Class ShutdownTracker

java.lang.Object

io.fabric8.utils.ShutdownTracker

public class ShutdownTracker
extends Object

A ShutdownTracker is used to track when a resource is in use so that a shutdown action can occur once all concurrent use of the resource has completed. Created by chirino on 6/23/14.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ShutdownTracker.ShutdownException

Constructor Summary

Constructors

Constructor and Description
ShutdownTracker()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	attemptRetain() Attempts to retain the the resources.
StandardMBean	mbeanProxy(Object target)
Object	proxy(Object target) Creates a dynamic proxy that implements all the interfaces of the target object and which retains/releases this ShutdownTracker before/after method invocations against the proxy.
void	release() This method should be called after a resource is no longer used.
void	retain() This method should be called before the resource is used.
void	shutdown(Runnable onStopCallback) Marks the resource as being in a shutdown state.
void	stop() Calls shutdown but waits for the shutdown to complete before this method returns.
<T> T	use(Callable<T> callable) This is a helper method which calls retain/release before and after a callable is called.

Methods inherited from class java.lang.Object

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

Constructor Detail

ShutdownTracker

public ShutdownTracker()

Method Detail

retain

public void retain()

This method should be called before the resource is used.

Throws:

ShutdownTracker.ShutdownException - once shutdown has been called.

attemptRetain

public boolean attemptRetain()

Attempts to retain the the resources.

Returns:

false if the resource has already shutdown.

release

public void release()

This method should be called after a resource is no longer used.

Throws:

IllegalStateException - if an unbalanced number of release() calls are done in respect to retain() calls.

use

public <T> T use(Callable<T> callable)
      throws Exception

This is a helper method which calls retain/release before and after a callable is called.

Type Parameters:

T -

Parameters:

callable -

Returns:

Throws:

Exception

shutdown

public void shutdown(Runnable onStopCallback)
              throws ShutdownTracker.ShutdownException

Marks the resource as being in a shutdown state. Once no more concurrent users of the resource are active, the onStopCallback will be run possibly after this method returns.

Parameters:

onStopCallback - if not null will be run once

Throws:

ShutdownTracker.ShutdownException - if shutdown has been previously called.

stop

public void stop()
          throws ShutdownTracker.ShutdownException,
                 InterruptedException

Calls shutdown but waits for the shutdown to complete before this method returns.

Throws:

ShutdownTracker.ShutdownException - if preciously shutdown.

InterruptedException - if this thread is interrupted before the shutdown completes.

proxy

public Object proxy(Object target)

Creates a dynamic proxy that implements all the interfaces of the target object and which retains/releases this ShutdownTracker before/after method invocations against the proxy.

Parameters:

target -

Returns:

mbeanProxy

public StandardMBean mbeanProxy(Object target)
                         throws NotCompliantMBeanException

Throws:

NotCompliantMBeanException