net.sf.basedb.clients.jobagent
Interface JobExecutor

All Known Implementing Classes:

DummyJobExecutor, ProcessJobExecutor, ThreadJobExecutor

public interface JobExecutor

This interface must be implemented by all classes that want's to act as a job executor. A job executor is responsible for executing a job when the job agent reqeusts so. The job executor to use is specfied by the agent.executor.class configuration setting.

Each agent only has one instance of a job executor, which means that a job executor must be thread-safe and able to execute more than one job at a time. It is not a good solution to put the synchonrized keyword on the executeJob(SessionControl, Agent, Job, JobAgentSettings, Job.ExecutionTime) method since it would limit the execution to one job at a time.

A job executor must provide a public no-argument constructor.

Version:

2.0

Author:

nicklas

Last modified

$Date: 2008-09-11 22:05:50 +0200 (Thu, 11 Sep 2008) $

Method Summary

void	close() This method is called at when the agent is stopped or paused.
void	executeJob(SessionControl sc, Agent agent, Job job, JobAgentSettings settings, Job.ExecutionTime usedSlot) Execute the specified job.
void	init(Agent agent) Initialize the job executor.

Method Detail

init

void init(Agent agent)

Initialize the job executor. This method is called once immediately after the object has been created.

Parameters:

agent - The agent

executeJob

void executeJob(SessionControl sc,
                Agent agent,
                Job job,
                JobAgentSettings settings,
                Job.ExecutionTime usedSlot)

Execute the specified job. This method is called in a new thread created specifically for running that job. If the agent is shutting down it will send an interrupt signal to all job threads. It is up to the job executor to decide how to handle this. It may either decide to kill the job or let it continue as if nothing happened.

The job sent to this method has it's status set to Job.Status.PREPARED. The implementation of this method must change the status to either Job.Status.DONE or Job.Status.ERROR. If the status hasn't changed the job agent will set the status to signal an unknown error.

Parameters:

sc - A SessionControl where the owner of the job is logged in and the correct active project is set

agent - The agent that sent the request to execute the job

job - The job to execute

settings - The specific settings used for the plugin on this job agent or null if no settings has been specified

usedSlot - The slot that was used to execut the job

close

void close()

This method is called at when the agent is stopped or paused. No more execution requests will be sent to the current job executor, but running jobs should NOT be terminated due to this method beeing called.