io.helixservice.feature.worker

Class BlockingWorkerFeature

java.lang.Object

io.helixservice.core.feature.AbstractFeature

io.helixservice.feature.worker.BlockingWorkerFeature

All Implemented Interfaces:

ComponentRegistry, Feature

public class BlockingWorkerFeature
extends AbstractFeature

Provides a easy way to make any method execute as blocking code. Annotating a method with @BlockingWorker makes the method run on a Vert.x Blocking Worker thread. While the Blocking Worker thread is running, the Event Loop thread is released to process other events. NOTE: Controller endpoint methods cannot be annotated as blocking methods If you need to execute blocking code from your controller, delegate to a business logic method (preferably in another class).

Request Context Propagation

The RequestContext will be propagated to the Blocking Worker thread, this ensures that any security, transaction, and logging related data are copied automatically.

Nested BlockingWorkers

It's okay to have one method annotated with @BlockingWorker call another method that is also annotated with @BlockingWorker. If the thread is already a Blocking Worker thread, then there is no attempt to execute the method on a different thread. Only one Blocking Worker thread will be used.

AspectJ Configuration

• AspectJ agent must be installed on the Java command line, for example:

  -javaagent:aspectjweaver-1.8.8.jar

• AspectJ aop.xml must contain

  <aspect name="io.helixservice.feature.worker.BlockingWorkerAspect"\>

Worker Thread Pool Configuration

By default, 50 threads are created to support concurrent blocking operations. The thread pool size can be tuned by modifying the configuration property vertx.server.workers

See Also:

Vert.x Blocking Worker

Constructor Summary

Constructors

Constructor and Description
BlockingWorkerFeature() Create the blocking worker feature

Method Summary

Modifier and Type	Method and Description
io.vertx.core.Vertx	getVertx()
static boolean	isOnWorkerThread() Call this method to test if your code is executing on a blocking worker thread.
void	start(Server server) Called by Helix Server when the server is starting.

Methods inherited from class io.helixservice.core.feature.AbstractFeature

findByType, findByType, finish, getFeatureName, getRegistrationMap, logFeatureDetails, register, stop

Methods inherited from class java.lang.Object

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

Constructor Detail

BlockingWorkerFeature

public BlockingWorkerFeature()

Create the blocking worker feature

Method Detail

isOnWorkerThread

public static boolean isOnWorkerThread()

Call this method to test if your code is executing on a blocking worker thread. This is more of a debugging aid, as the thread will be checked before the method executes to ensure the method code is executing on a Vert.x Worker Thread.

Returns:

True if the executing code is running on a worker thread

start

public void start(Server server)

Description copied from class: AbstractFeature

Called by Helix Server when the server is starting.

The order features will be called is the same order they initially registered with Helix. At the time this method is called, Vert.x will be initialized enabling the feature to create any Vert.x related resources.

Features should create and register any singleton components and allocate resources during the start call. Blocking operations are allowed in this method.

Specified by:

start in interface Feature

Overrides:

start in class AbstractFeature

Parameters:

server - Helix Server that is starting up

getVertx

public io.vertx.core.Vertx getVertx()