org.lsst.ccs.services

Class LocalAgentLockService

java.lang.Object

org.lsst.ccs.services.AbstractAgentLockServiceDelegate

org.lsst.ccs.services.LocalAgentLockService

All Implemented Interfaces:

AgentPresenceListener, AgentLockServiceDelegate, AgentLoginService.AgentLoginUpdateListener

public class LocalAgentLockService
extends AbstractAgentLockServiceDelegate

Client side locking service, for a given agent. It is attached to an instance of Agent, which is any agent with type >= CONSOLE. It provides an API both for consoles that need to lock/unlock a WORKER subsystem, and for WORKER subsystem that need to check the validity of a lock attached with a command request. It encapsulates the communication protocol with the centralized LockManager subsystem.

Author:

LSST CCS Team

Field Summary

Fields inherited from class org.lsst.ccs.services.AbstractAgentLockServiceDelegate

agentLevels, agentLockUpdateListeners, allLocks, heldLocks, listenerUpdatesLock, log, myCurrentLock, svc

Constructor Summary

Constructors

Constructor and Description
LocalAgentLockService(AgentLockService svc)

Method Summary

Modifier and Type	Method and Description
void	attachLock(String agentName)
void	destroyLock(String agentName, String userId)
void	detachLock(String agentName)
void	disconnected(AgentInfo... agents) Invoked when one or more agents are disconnected from this cluster, either because the shutdown or because they were lost.
Map<String,AgentLock>	getLocks()
void	lockAgent(String agentName) Request for this agent to obtain a lock on the given subsystem.
void	preInit()
void	preStart()
void	setLevelForAgent(String agentName, int level) Set this agent's operational level for the given subsystem.
void	unlockAgent(String agentName) Request for this agent to release a lock on the given subsystem.
boolean	validateLock(AgentLock lock)

Methods inherited from class org.lsst.ccs.services.AbstractAgentLockServiceDelegate

addAgentLockUpdateListener, addHeldLock, getAgent, getAgentStateService, getAllWorkerAgents, getAttachableAgents, getCurrentLock, getDetachableAgents, getExistingLockForAgent, getHeldLocks, getLevelForAgent, getLocallyLockedAgents, getLockableAgents, getLockedAgents, getLockForAgent, notifyGlobalLockListeners, notifyHeldLockListeners, notifyLevelListeners, notifyLockListeners, notifyLockVisibility, onAgentLoginUpdate, removeAgentLockUpdateListener, removeCurrentLock, removeHeldLock, setCurrentLock, setLevelInternal

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.lsst.ccs.messaging.AgentPresenceListener

connected, connecting, disconnecting

Constructor Detail

LocalAgentLockService

public LocalAgentLockService(AgentLockService svc)

Method Detail

setLevelForAgent

public void setLevelForAgent(String agentName,
                             int level)
                      throws UnauthorizedLevelException,
                             UnauthorizedLockException

Set this agent's operational level for the given subsystem. If this agent does not hold a lock on the subsystem, this method will first attempt to acquire a lock on the subsystem. If successful, registered AgentLevelListener will be notified with the new level value

Parameters:

agentName - the subsystem for which to change the level

level - the level to set

Throws:

UnauthorizedLevelException - if the requested level cannot be set. This happens if this agent owns a lock on the given subsystem and that lock defines a maximum level that is lower than the requested level, or if this agent does not hold a lock on the given subsystem and this agent's default subsystem level is lower than the requested level.

UnauthorizedLockException - if the user is not allowed to acquire a lock on the specified Agent

IOException - if there was a communication problem on the buses.

lockAgent

public void lockAgent(String agentName)
               throws UnauthorizedLockException

Description copied from interface: AgentLockServiceDelegate

Request for this agent to obtain a lock on the given subsystem. If successful, this agent will own a lock on the requested subsystem. registered AgentLockUpdateListener will be notified. The list of owned valid locks will be updated.

Throws:

UnauthorizedLockException - if the user is not allowed to acquire a lock on the specified Agent

attachLock

public void attachLock(String agentName)
                throws UnauthorizedLockException

Throws:

UnauthorizedLockException

detachLock

public void detachLock(String agentName)
                throws UnauthorizedLockException

Throws:

UnauthorizedLockException

unlockAgent

public void unlockAgent(String agentName)

Description copied from interface: AgentLockServiceDelegate

Request for this agent to release a lock on the given subsystem. If successful, this agent will lose its lock on the requested subsystem. Registered AgentLockUpdateListener and AgentLevelListener will be notified. The list of owned valid locks will be updated.

disconnected

public void disconnected(AgentInfo... agents)

Description copied from interface: AgentPresenceListener

Invoked when one or more agents are disconnected from this cluster, either because the shutdown or because they were lost. The implementation should return immediately : any blocking operations should be scheduled on a separate thread.

getLocks

public Map<String,AgentLock> getLocks()

Specified by:

getLocks in interface AgentLockServiceDelegate

Overrides:

getLocks in class AbstractAgentLockServiceDelegate

preStart

public void preStart()

Specified by:

preStart in interface AgentLockServiceDelegate

Overrides:

preStart in class AbstractAgentLockServiceDelegate

preInit

public void preInit()

Specified by:

preInit in interface AgentLockServiceDelegate

Overrides:

preInit in class AbstractAgentLockServiceDelegate

validateLock

public boolean validateLock(AgentLock lock)

Specified by:

validateLock in interface AgentLockServiceDelegate

Overrides:

validateLock in class AbstractAgentLockServiceDelegate

destroyLock

public void destroyLock(String agentName,
                        String userId)