tp.impl
Class CSEP545ServiceObject

java.lang.Object
  tp.impl.CSEP545ServiceObject

All Implemented Interfaces:

Remote, CSEP545Service

Direct Known Subclasses:

MyRM, MyTM, MyWC

public abstract class CSEP545ServiceObject
extends Object
implements CSEP545Service

A stub class to drive project services.

Bootstrap

The bootstrap happens in the following order.

1. process common command line arguments
2. cleanup storage directory if necessary
3. init(String[])
4. initStorage() if initializing the storage or recovery() if storage exists
5. startUp()
6. Registry.rebind(String, Remote)
7. readyToServe()

Common arguments

The following arguments are processed by this class.

Argument	Description	Default
-n name or --name name	the name of service	Type of service
-p port or --port port	port number to bind the service	anonymous port
-d dir or --dir dir	the data directory where all necessary files are.	'./' ServiceID '-data'
--init	initialize the data directory. will wipe out data directory if it exists. initialize if data directory does not exist, recovery() otherwise.	Do not force initialization
--rmiHost host	host name of RMI registry	127.0.0.1
--rmiPort port	port number of RMI registry.	1099
-c URI or --code URI	RMI server code base URL	http://127.0.0.1:8080/csep545.jar

Nested Class Summary

Nested classes/interfaces inherited from interface tp.impl.CSEP545Service

CSEP545Service.Type

Field Summary

protected File	dir directory to store all data files
protected Registry	registry reference to RMI registry
protected ServiceID	svcid service identifier.

Constructor Summary

CSEP545ServiceObject()

Method Summary

File	getDataRoot() Get root directory where local data files are located.
ServiceID	getServiceID() Name of remote service object
protected abstract void	init(String[] args) IMPLEMENT THIS METHOD process command line parameters and setup any parameterized values.
protected abstract void	initStorage() IMPLEMENT THIS METHOD Initialize necessary data files.
void	kill() Immediately kill remote service.
protected <T extends Remote> Map<String,T>	lookupRemote(CSEP545Service.Type type)
protected <T extends Remote> T	lookupRemote(CSEP545Service.Type type, String name) utility method to resolve remote object
protected <T extends Remote> T	lookupRemote(ServiceID id) utility method to resolve remote object
protected <T extends Remote> T	lookupRemote(String name) utility method to resolve remote object
static void	main(String[] args)
protected abstract void	readyToServe() IMPLEMENT THIS METHOD Bootstrapping completed and the server is up and running.
protected abstract void	recovery() IMPLEMENT THIS METHOD Run recovery algorithm and reconstruct the state of service before failure.
void	shutdown() Gracefully shutdown target service.
protected abstract void	startUp() IMPLEMENT THIS METHOD If you use extra threads in your service, start them in this method.

Methods inherited from class java.lang.Object

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

Methods inherited from interface tp.impl.CSEP545Service

refresh

Field Detail

svcid

protected ServiceID svcid

service identifier. must be unique per instance.

dir

protected File dir

directory to store all data files

registry

protected transient Registry registry

reference to RMI registry

Constructor Detail

CSEP545ServiceObject

public CSEP545ServiceObject()

Method Detail

kill

public final void kill()
                throws RemoteException

Description copied from interface: CSEP545Service

Immediately kill remote service. Useful for automated testing.

Specified by:

kill in interface CSEP545Service

Throws:

RemoteException

shutdown

public void shutdown()
              throws RemoteException

Description copied from interface: CSEP545Service

Gracefully shutdown target service. On restart, the service should not need to recover its state. Please make sure to call Registry.unbind(String)

Specified by:

shutdown in interface CSEP545Service

Throws:

RemoteException

See Also:

Registry.unbind(String)

getServiceID

public final ServiceID getServiceID()

Description copied from interface: CSEP545Service

Name of remote service object

Specified by:

getServiceID in interface CSEP545Service

Returns:

A string represent remote service object

getDataRoot

public final File getDataRoot()

Get root directory where local data files are located. By default, getServiceID() '-data' under working directory.

Returns:

root directory to place data files

init

protected abstract void init(String[] args)
                      throws Exception

IMPLEMENT THIS METHOD process command line parameters and setup any parameterized values. For example, setting self destruct counter should be done in this method.

Parameters:

args - command line arguments except common arguments

Throws:

Exception

initStorage

protected abstract void initStorage()
                             throws Exception

IMPLEMENT THIS METHOD Initialize necessary data files. Invoked in two cases.

• the data directory is newly created.
• --init flag is set in command line.

For example, you can create database files for RM and commit log file for TM

Throws:

Exception

recovery

protected abstract void recovery()
                          throws Exception

IMPLEMENT THIS METHOD Run recovery algorithm and reconstruct the state of service before failure. This method is invoked when the data directory already exists. Note that if the service has been shutdown cleanly, calling this method should not affect the state.

Throws:

Exception

startUp

protected abstract void startUp()
                         throws Exception

IMPLEMENT THIS METHOD If you use extra threads in your service, start them in this method. For example, you can launch periodic deadlock-detector thread here. Or, any kinds of asynchronous taks such as timeout-retry, failure detector, etc.

Throws:

Exception

readyToServe

protected abstract void readyToServe()
                              throws Exception

IMPLEMENT THIS METHOD Bootstrapping completed and the server is up and running.

Throws:

Exception

lookupRemote

protected <T extends Remote> T lookupRemote(String name)
                                 throws AccessException,
                                        RemoteException,
                                        NotBoundException

utility method to resolve remote object

Parameters:

name - bind name of remote object

Returns:

remote object stub

Throws:

AccessException

RemoteException

NotBoundException

lookupRemote

protected <T extends Remote> T lookupRemote(ServiceID id)
                                 throws AccessException,
                                        RemoteException,
                                        NotBoundException

utility method to resolve remote object

Parameters:

id - bind name of remote object

Returns:

remote object stub

Throws:

AccessException

RemoteException

NotBoundException

lookupRemote

protected <T extends Remote> T lookupRemote(CSEP545Service.Type type,
                                            String name)
                                 throws AccessException,
                                        RemoteException,
                                        NotBoundException

utility method to resolve remote object

Parameters:

type - type of remove object

Returns:

remote object stub

Throws:

AccessException

RemoteException

NotBoundException

lookupRemote

protected <T extends Remote> Map<String,T> lookupRemote(CSEP545Service.Type type)
                                             throws AccessException,
                                                    RemoteException,
                                                    NotBoundException

Throws:

AccessException

RemoteException

NotBoundException

main

public static void main(String[] args)
                 throws Exception

Parameters:

args -

Throws:

Exception