com.spotify.helios.agent

Class SignalAwaitingService

java.lang.Object

com.google.common.util.concurrent.AbstractIdleService

com.spotify.helios.agent.InterruptingScheduledService

com.spotify.helios.agent.SignalAwaitingService

All Implemented Interfaces:

com.google.common.util.concurrent.Service

Direct Known Subclasses:

AgentInfoReporter, EnvironmentVariableReporter, HostInfoReporter, LabelReporter

public abstract class SignalAwaitingService
extends InterruptingScheduledService

An InterruptingScheduledService which awaits on a CountDownLatch prior to InterruptingScheduledService.runOneIteration(). This can be used to have the Service fully enter the RUNNING state and schedule it's periodic task, but block the actual execution of the task until some condition is met by another thread.

Implementation note: await() is called in the thread running the "periodic task" as it is easier to interrupt that thread when the Service is shut down; blocking on the latch in the startUp() method caused the Service to never exit (and prevent the JVM from exiting normally on SIGINT).

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.common.util.concurrent.Service

com.google.common.util.concurrent.Service.Listener, com.google.common.util.concurrent.Service.State

Constructor Summary

Constructors

Constructor and Description
SignalAwaitingService(CountDownLatch signal)

Method Summary

Modifier and Type	Method and Description
protected void	beforeIteration() A hook for subclasses to insert extra steps before InterruptingScheduledService.runOneIteration().

Methods inherited from class com.spotify.helios.agent.InterruptingScheduledService

runOneIteration, schedule, shutDown, startUp

Methods inherited from class com.google.common.util.concurrent.AbstractIdleService

addListener, awaitRunning, awaitRunning, awaitTerminated, awaitTerminated, executor, failureCause, isRunning, serviceName, startAsync, state, stopAsync, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

SignalAwaitingService

public SignalAwaitingService(CountDownLatch signal)

Method Detail

beforeIteration

protected void beforeIteration()
                        throws InterruptedException

Description copied from class: InterruptingScheduledService

A hook for subclasses to insert extra steps before InterruptingScheduledService.runOneIteration().

Overrides:

beforeIteration in class InterruptingScheduledService

Throws:

InterruptedException