Package org.axonframework.common.lifecycle

Class ShutdownLatch

java.lang.Object

org.axonframework.common.lifecycle.ShutdownLatch

public class ShutdownLatch
extends Object

A latch implementation to be used in shutdown scenarios. Activities to wait for can be added by invoking registerActivity(). A registered activity should always shutdown through the returned ShutdownLatch.ActivityHandle's ShutdownLatch.ActivityHandle.end() method once it has completed. Otherwise initiateShutdown() will block indefinitely. If the latch is waited on through initiateShutdown(), new operations can no longer be registered.

Since:

4.3

Author:

Steven van Beelen

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	ShutdownLatch.ActivityHandle	A handle for an activity registered to a ShutdownLatch.

Constructor Summary

Constructors

Constructor	Description
ShutdownLatch()

Method Summary

Modifier and Type	Method	Description
void	ifShuttingDown(String exceptionMessage)	Check whether this ShutdownLatch is shutting down.
void	ifShuttingDown(Supplier<RuntimeException> exceptionSupplier)	Check whether this ShutdownLatch is shutting down.
void	initialize()	Initialize this ShutdownLatch.
CompletableFuture<Void>	initiateShutdown()	Initiate the shutdown of this latch.
boolean	isShuttingDown()	Check whether this ShutdownLatch is shutting down.
ShutdownLatch.ActivityHandle	registerActivity()	Add an activity this latch should wait on before opening up.

Methods inherited from class java.lang.Object

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

Constructor Details

ShutdownLatch

public ShutdownLatch()

Method Details

initialize

public void initialize()

Initialize this ShutdownLatch. If the latch was already closed through initiateShutdown(), then that operation will be canceled.

registerActivity

public ShutdownLatch.ActivityHandle registerActivity()

Add an activity this latch should wait on before opening up. If this operation is invoked whilst initiateShutdown() has already been called a ShutdownInProgressException will be thrown.

Returns:

an ShutdownLatch.ActivityHandle to ShutdownLatch.ActivityHandle.end() the registered activity once it is done

Throws:

ShutdownInProgressException - if initiateShutdown() has been called prior to invoking this method

ifShuttingDown

public void ifShuttingDown(String exceptionMessage)

Check whether this ShutdownLatch is shutting down. The given exceptionMessage is used in the thrown ShutdownInProgressException, if this latch is shutting down.

Parameters:

exceptionMessage - the message used for the ShutdownInProgressException to throw if this latch is shutting down

ifShuttingDown

public void ifShuttingDown(Supplier<RuntimeException> exceptionSupplier)

Check whether this ShutdownLatch is shutting down. The exception retrieved from the exceptionSupplier will be thrown if this latch is shutting down.

Parameters:

exceptionSupplier - a Supplier of a RuntimeException to throw if this latch is waited on

isShuttingDown

public boolean isShuttingDown()

Check whether this ShutdownLatch is shutting down.

Returns:

true if the latch is waited on, false otherwise

initiateShutdown

public CompletableFuture<Void> initiateShutdown()

Initiate the shutdown of this latch. The returned CompletableFuture will complete once all activities have been ended or complete immediately if no activities are active.

Returns:

a CompletableFuture which completes once all activities are done