Package hudson.util

Class DoubleLaunchChecker

java.lang.Object

hudson.model.AbstractModelObject

hudson.model.AdministrativeMonitor

hudson.util.DoubleLaunchChecker

All Implemented Interfaces:

ExtensionPoint, ModelObject, SearchableModelObject, SearchItem, org.kohsuke.stapler.StaplerProxy

@Extension
public class DoubleLaunchChecker
extends AdministrativeMonitor

Makes sure that no other Hudson uses our JENKINS_HOME directory, to forestall the problem of running multiple instances of Hudson that point to the same data directory.

This set up error occasionally happens especially when the user is trying to reassign the context path of the app, and it results in a hard-to-diagnose error, so we actively check this.

The mechanism is simple. This class occasionally updates a known file inside the hudson home directory, and whenever it does so, it monitors the timestamp of the file to make sure no one else is updating this file. In this way, while we cannot detect the problem right away, within a reasonable time frame we can detect the collision.

Since:

1.178

Author:

Kohsuke Kawaguchi

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	DoubleLaunchChecker.Schedule

Nested classes/interfaces inherited from interface hudson.ExtensionPoint

ExtensionPoint.LegacyInstancesAreScopedToHudson

Field Summary

Fields

Modifier and Type	Field	Description
final File	home

Fields inherited from class hudson.model.AdministrativeMonitor

id

Constructor Summary

Constructors

Constructor	Description
DoubleLaunchChecker()

Method Summary

Modifier and Type	Method	Description
protected void	execute()
String	getCollidingId()
String	getDisplayName()
String	getId()	Figures out a string that identifies this instance of Hudson.
boolean	isActivated()	Returns true if this monitor is activated and wants to produce a warning message.

Methods inherited from class hudson.model.AdministrativeMonitor

all, checkRequiredPermission, disable, doDisable, getRequiredPermission, getSearchUrl, getTarget, getUrl, hasPermissionToDisplay, hasRequiredPermission, isActivationFake, isEnabled, isSecurity

Methods inherited from class hudson.model.AbstractModelObject

getSearch, getSearchIndex, getSearchName, makeSearchIndex, requirePOST, sendError, sendError, sendError, sendError, sendError, sendError, sendError, sendError

Methods inherited from class java.lang.Object

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

Methods inherited from interface hudson.search.SearchItem

getSearchGroup, getSearchIcon

Field Details

home

public final File home

Constructor Details

DoubleLaunchChecker

public DoubleLaunchChecker()

Method Details

getDisplayName

public String getDisplayName()

Specified by:

getDisplayName in interface ModelObject

Overrides:

getDisplayName in class AdministrativeMonitor

isActivated

public boolean isActivated()

Description copied from class: AdministrativeMonitor

Returns true if this monitor is activated and wants to produce a warning message.

This method is called from the HTML rendering thread, so it should run efficiently.

Specified by:

isActivated in class AdministrativeMonitor

execute

protected void execute()

getId

public String getId()

Figures out a string that identifies this instance of Hudson.

getCollidingId

public String getCollidingId()