org.agrona.concurrent

Class CompositeAgent

java.lang.Object

org.agrona.concurrent.CompositeAgent

All Implemented Interfaces:

Agent

public class CompositeAgent
extends java.lang.Object
implements Agent

Group several Agents into one composite so they can be scheduled as a unit.

Constructor Summary

Constructors

Constructor and Description
CompositeAgent(Agent... agents)
CompositeAgent(java.util.List<? extends Agent> agents)

Method Summary

Modifier and Type	Method and Description
int	doWork() An agent should implement this method to do its work.
void	onClose() To be overridden by Agents that need to do resource cleanup on close.
void	onStart() To be overridden by Agents that need to do resource init on start.
java.lang.String	roleName() Get the name of this agent's role.

Methods inherited from class java.lang.Object

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

Constructor Detail

CompositeAgent

public CompositeAgent(java.util.List<? extends Agent> agents)

Parameters:

agents - the parts of this composite, at least one agent and no null agents allowed

Throws:

java.lang.IllegalArgumentException - if an empty array of agents is provided

java.lang.NullPointerException - if the array or any element is null

CompositeAgent

public CompositeAgent(Agent... agents)

Parameters:

agents - the parts of this composite, at least one agent and no null agents allowed

Throws:

java.lang.IllegalArgumentException - if an empty array of agents is provided, or single agent provided

java.lang.NullPointerException - if the array or any element is null

Method Detail

roleName

public java.lang.String roleName()

Description copied from interface: Agent

Get the name of this agent's role.

Specified by:

roleName in interface Agent

Returns:

the name of this agent's role.

onStart

public void onStart()

To be overridden by Agents that need to do resource init on start.

This method will be called by the agent thread thread once on start..

Note that one agent throwing an exception on start will not prevent other agents from being started.

Specified by:

onStart in interface Agent

Throws:

java.lang.RuntimeException - if any sub-agent throws an exception onStart. The agents exceptions are collected as suppressed exceptions in the thrown exception.

doWork

public int doWork()
           throws java.lang.Exception

Description copied from interface: Agent

An agent should implement this method to do its work.

The return value is used for implementing a backoff strategy that can be employed when no work is currently available for the agent to process.

If the Agent wished to terminate and close then a AgentTerminationException can be thrown.

Specified by:

doWork in interface Agent

Returns:

0 to indicate no work was currently available, a positive value otherwise.

Throws:

java.lang.Exception - if an error has occurred

onClose

public void onClose()

To be overridden by Agents that need to do resource cleanup on close.

This method will be called after the agent thread has terminated or if the agent is closed before it runs.

Note that one agent throwing an exception on close will not prevent other agents from being closed.

Specified by:

onClose in interface Agent

Throws:

java.lang.RuntimeException - if any sub-agent throws an exception onClose. The agents exceptions are collected as suppressed exceptions in the thrown exception.