org.jmux.app.component
Class SingletonProcess

java.lang.Object
  org.jmux.app.component.AbstractComponent
      org.jmux.app.component.AbstractControl
          org.jmux.app.component.SingletonProcess

All Implemented Interfaces:

Component, Control

public class SingletonProcess
extends AbstractControl

This component ensures that only one version of an application is started on a single machine. Given Java's lack of system wide mutexes, the way we to do this is to try to bind a to a socket. A less resource expensive alternative would be to use java.nio locking. I'm not sure how portable this is though. In some environments, atomic locking is flaky at best. Older implementations of NFS on Linux come to mind.

Configuration settings

• port The port number we bind to for locking purposes
• halt Halt the system if true, else (default) shutdown nicely

Author:

donaldw

Constructor Summary

SingletonProcess()

Method Summary

void	configure(Config config, App app)
void	start()
void	stop()

Methods inherited from class org.jmux.app.component.AbstractComponent

getConfig, log, logDebug, logDebug, logError, logError

Methods inherited from class java.lang.Object

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

Constructor Detail

SingletonProcess

public SingletonProcess()

Method Detail

configure

public void configure(Config config,
                      App app)

Specified by:

configure in interface Component

Overrides:

configure in class AbstractComponent

start

public void start()

stop

public void stop()