Package org.agrona.concurrent

Class AgentInvoker

java.lang.Object
org.agrona.concurrent.AgentInvoker
All Implemented Interfaces:
AutoCloseable
public class AgentInvoker extends Object implements AutoCloseable
Agent container which does not start a thread. It instead allows the duty cycle Agent.doWork() to be invoked directly. start() should be called to allow the Agent.onStart() to fire before any calls to invoke() of the agent duty cycle.

Exceptions which occur during the Agent.doWork() invocation will be caught and passed to the provided ErrorHandler.

Note: This class is not threadsafe.

  • Constructor Details

    • AgentInvoker

      public AgentInvoker(ErrorHandler errorHandler, AtomicCounter errorCounter, Agent agent)
      Create an agent and initialise it.
      Parameters:
      errorHandler - to be called if an Throwable is encountered
      errorCounter - to be incremented each time an exception is encountered. This may be null.
      agent - to be run in this thread.

  • Method Details

    • isStarted

      public boolean isStarted()
      Has the Agent been started?
      Returns:
      has the Agent been started?

    • isRunning

      public boolean isRunning()
      Has the Agent been running?
      Returns:
      has the Agent been started successfully and not closed?

    • isClosed

      public boolean isClosed()
      Has the Agent been closed?
      Returns:
      has the Agent been closed?

    • agent

      public Agent agent()
      The Agent which is contained.
      Returns:
      Agent being contained.

    • start

      public void start()
      Mark the invoker as started and call the Agent.onStart() method.

      Startup logic will only be performed once.

    • invoke

      public int invoke()
      Invoke the Agent.doWork() method and return the work count.

      If an error occurs then the AtomicCounter.increment() will be called on the errorCounter if not null and the Throwable will be passed to the ErrorHandler.onError(Throwable) method. If the error is an AgentTerminationException then close() will be called after the error handler.

      If not successfully started or after closed then this method will return without invoking the Agent.

      Returns:
      the work count for the Agent.doWork() method.

    • close

      public final void close()
      Mark the invoker as closed and call the Agent.onClose() logic for clean up.

      The cleanup logic will only be performed once.

      Specified by:
      close in interface AutoCloseable