tp.impl
Class MyRM

java.lang.Object
  tp.impl.CSEP545ServiceObject
      tp.impl.MyRM

All Implemented Interfaces:

Remote, CSEP545Service, RM

public class MyRM
extends CSEP545ServiceObject
implements RM

Your Resource Manager. Rudimentary implementation is provided for your convenience.

Command line arguments

The following arguments are further processed by this class in addition to common arguments processed by CSEP545ServiceObject.main(String[]).

• -x or --selfdestruct numio: Set the self destruction timer on this RM. If this argument is given, the RM MUST call System.exit() immediately after numio disk operations. (default: 0. no self destruction)
• -t or --timeout s: Set deadlock detection timeout to s seconds. (default: LM.DEFAULT_DEADLOCK_TIMEOUT)

See Also:

CSEP545ServiceObject

Nested Class Summary

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

CSEP545Service.Type

Field Summary

Fields inherited from class tp.impl.CSEP545ServiceObject

dir, registry, svcid

Constructor Summary

MyRM()

Method Summary

void	abort(Transaction xid) abort transaction
boolean	add(Transaction xid, RID i, int count, int price) add qty items described by resource.
void	commit(Transaction xid) commit transaction
boolean	delete(Transaction xid, RID rid) Drop resource from this RM.
boolean	delete(Transaction xid, RID i, int count) Remove exactly qty unreserved resource from this RM.
String	getName() get the name of this RM
protected void	init(String[] args) IMPLEMENT THIS METHOD process command line parameters and setup any parameterized values.
protected void	initStorage() IMPLEMENT THIS METHOD Initialize necessary data files.
Customer[]	listCustomers(Transaction context) list of customers who reserve resources managed by this RM
String[]	listResources(Transaction context, RID.Type type) list of resources
int	query(Transaction xid, RID rid) query: equivalent to queryCars, queryFlights, queryRooms
int	queryPrice(Transaction xid, RID i) query: equivalent to queryCarsPrice, queryFlightsPrice, queryRoomsPrice
String	queryReserved(Transaction context, Customer customer) Get the bill for the customer return a string representation of reservations
int	queryReservedPrice(Transaction context, Customer customer) Get the total amount of money the customer owes in this RM.
protected void	readyToServe() IMPLEMENT THIS METHOD Bootstrapping completed and the server is up and running.
protected void	recovery() IMPLEMENT THIS METHOD Run recovery algorithm and reconstruct the state of service before failure.
void	refresh() Refresh all remote references used by this service.
boolean	reserve(Transaction context, Customer c, RID i) reserve a resource i on behalf of customer c
void	selfDestruct(int diskWritesToWait) Exit (simulate a failure) after a specified number of disk writes.
void	shutdown() Gracefully shutdown target service.
protected void	startUp() IMPLEMENT THIS METHOD If you use extra threads in your service, start them in this method.
void	unreserve(Transaction context, Customer c) drop all reserved resources for customer customer

Methods inherited from class tp.impl.CSEP545ServiceObject

getDataRoot, getServiceID, kill, lookupRemote, lookupRemote, lookupRemote, lookupRemote, main

Methods inherited from class java.lang.Object

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

Constructor Detail

MyRM

public MyRM()

Method Detail

commit

public void commit(Transaction xid)
            throws InvalidTransactionException,
                   TransactionAbortedException,
                   RemoteException

Description copied from interface: RM

commit transaction

Specified by:

commit in interface RM

Parameters:

xid - transaction identifier

Throws:

InvalidTransactionException

TransactionAbortedException

RemoteException

abort

public void abort(Transaction xid)
           throws RemoteException

Description copied from interface: RM

abort transaction

Specified by:

abort in interface RM

Parameters:

xid - transaction identifier

Throws:

RemoteException

add

public boolean add(Transaction xid,
                   RID i,
                   int count,
                   int price)
            throws TransactionAbortedException,
                   InvalidTransactionException,
                   RemoteException

Description copied from interface: RM

add qty items described by resource. If resource does not exist in the RM, create a new one.

Specified by:

add in interface RM

Parameters:

xid - transaction identifier

i - resource identifier

count - quantity (seats, cars, rooms)

price - price per unit

Returns:

true on success. false otherwise

Throws:

TransactionAbortedException

InvalidTransactionException

RemoteException

See Also:

WC.addSeats(Transaction, String, int, int), WC.addCars(Transaction, String, int, int), WC.addRooms(Transaction, String, int, int)

delete

public boolean delete(Transaction xid,
                      RID rid)
               throws TransactionAbortedException,
                      InvalidTransactionException,
                      RemoteException

Description copied from interface: RM

Drop resource from this RM. All reservations on resource must be dropped as well.

Specified by:

delete in interface RM

Parameters:

xid - transaction identifier

rid - resource identifier

Throws:

TransactionAbortedException

InvalidTransactionException

RemoteException

See Also:

WC.deleteFlight(Transaction, String)

delete

public boolean delete(Transaction xid,
                      RID i,
                      int count)
               throws TransactionAbortedException,
                      InvalidTransactionException,
                      RemoteException

Description copied from interface: RM

Remove exactly qty unreserved resource from this RM.

Specified by:

delete in interface RM

Parameters:

xid - transaction identifier

i - resource identifier

count - number of resource to remove. -1 removes all remaining

Returns:

true on successful deletion. If there is no such resource, return true. false otherwise. If there are not enough qty to remove, return false.

Throws:

TransactionAbortedException

InvalidTransactionException

RemoteException

See Also:

WC.deleteSeats(Transaction, String, int), WC.deleteCars(Transaction, String, int), WC.deleteRooms(Transaction, String, int)

query

public int query(Transaction xid,
                 RID rid)
          throws TransactionAbortedException,
                 InvalidTransactionException,
                 RemoteException

Description copied from interface: RM

query: equivalent to queryCars, queryFlights, queryRooms

Specified by:

query in interface RM

Parameters:

xid - transaction identifier

rid - resource identifier

Returns:

available quantity

Throws:

TransactionAbortedException

InvalidTransactionException

RemoteException

See Also:

WC.queryCar(Transaction, String), WC.queryRoom(Transaction, String), WC.queryFlight(Transaction, String)

queryPrice

public int queryPrice(Transaction xid,
                      RID i)
               throws TransactionAbortedException,
                      InvalidTransactionException,
                      RemoteException

Description copied from interface: RM

query: equivalent to queryCarsPrice, queryFlightsPrice, queryRoomsPrice

Specified by:

queryPrice in interface RM

Parameters:

xid - transaction identifier

i - resource identifier

Returns:

price per unit for requested item resource

Throws:

TransactionAbortedException

InvalidTransactionException

RemoteException

See Also:

WC.queryCarPrice(Transaction, String), WC.queryRoomPrice(Transaction, String), WC.queryFlightPrice(Transaction, String)

queryReserved

public String queryReserved(Transaction context,
                            Customer customer)
                     throws TransactionAbortedException,
                            InvalidTransactionException,
                            RemoteException

Description copied from interface: RM

Get the bill for the customer return a string representation of reservations

Specified by:

queryReserved in interface RM

Parameters:

context - the transaction ID

customer - the customer ID

Returns:

a string representation of reservations

Throws:

TransactionAbortedException

InvalidTransactionException

RemoteException

See Also:

WC.queryItinerary(Transaction, Customer)

queryReservedPrice

public int queryReservedPrice(Transaction context,
                              Customer customer)
                       throws TransactionAbortedException,
                              InvalidTransactionException,
                              RemoteException

Description copied from interface: RM

Get the total amount of money the customer owes in this RM.

Specified by:

queryReservedPrice in interface RM

Parameters:

context - the transaction ID

customer - the customer ID

Returns:

total price of all reservations

Throws:

TransactionAbortedException

InvalidTransactionException

RemoteException

See Also:

WC.queryItineraryPrice(Transaction, Customer)

reserve

public boolean reserve(Transaction context,
                       Customer c,
                       RID i)
                throws TransactionAbortedException,
                       InvalidTransactionException,
                       RemoteException

Description copied from interface: RM

reserve a resource i on behalf of customer c

Specified by:

reserve in interface RM

Parameters:

context - the transaction ID

c - the customer ID

i - resource to reserve

Returns:

true on successful reservation. false otherwise.

Throws:

TransactionAbortedException

InvalidTransactionException

RemoteException

See Also:

WC.reserveItinerary(Customer, String[], String, boolean, boolean)

unreserve

public void unreserve(Transaction context,
                      Customer c)
               throws TransactionAbortedException,
                      InvalidTransactionException,
                      RemoteException

Description copied from interface: RM

drop all reserved resources for customer customer

Specified by:

unreserve in interface RM

Parameters:

context - the transaction ID

c - the customer ID

Throws:

TransactionAbortedException

InvalidTransactionException

RemoteException

See Also:

WC.cancelItinerary(Customer)

listResources

public String[] listResources(Transaction context,
                              RID.Type type)
                       throws TransactionAbortedException,
                              InvalidTransactionException,
                              RemoteException

Description copied from interface: RM

list of resources

Specified by:

listResources in interface RM

type - listing resource type

Returns:

array of comma separated strings of available resource information. The format of each string is following:

resource name ',' available quantity ',' price

Throws:

TransactionAbortedException

InvalidTransactionException

RemoteException

See Also:

WC.listCars(Transaction), WC.listFlights(Transaction), WC.listRooms(Transaction)

listCustomers

public Customer[] listCustomers(Transaction context)
                         throws TransactionAbortedException,
                                InvalidTransactionException,
                                RemoteException

Description copied from interface: RM

list of customers who reserve resources managed by this RM

Specified by:

listCustomers in interface RM

Parameters:

context - the transaction ID

Returns:

list of customers

Throws:

TransactionAbortedException

InvalidTransactionException

RemoteException

See Also:

WC.listCustomers(Transaction)

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

Overrides:

shutdown in class CSEP545ServiceObject

Throws:

RemoteException

See Also:

Registry.unbind(String)

selfDestruct

public void selfDestruct(int diskWritesToWait)
                  throws RemoteException

Description copied from interface: RM

Exit (simulate a failure) after a specified number of disk writes. Support for this method requires a wrapper around the system's write system call that decrements the counter set by this method. This counter should be set to zero by default, which makes the wrapper doing nothing. If the counter is non-zero, the wrapper should decrement it, see if it is zero, and if so call exit(). This method is not part of a transaction. It is intended to simulate an RM failure.

Specified by:

selfDestruct in interface RM

Parameters:

diskWritesToWait - number of disk writes to wait until terminate

Throws:

RemoteException

getName

public String getName()
               throws RemoteException

Description copied from interface: RM

get the name of this RM

Specified by:

getName in interface RM

Returns:

the name of this RM

Throws:

RemoteException

init

protected void init(String[] args)
             throws Exception

Description copied from class: CSEP545ServiceObject

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

Specified by:

init in class CSEP545ServiceObject

Parameters:

args - command line arguments except common arguments

Throws:

Exception

To do:

setup selfDestruct(int) here

initStorage

protected void initStorage()
                    throws Exception

Description copied from class: CSEP545ServiceObject

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

Specified by:

initStorage in class CSEP545ServiceObject

Throws:

Exception

recovery

protected void recovery()
                 throws Exception

Description copied from class: CSEP545ServiceObject

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.

Specified by:

recovery in class CSEP545ServiceObject

Throws:

Exception

startUp

protected void startUp()
                throws Exception

Description copied from class: CSEP545ServiceObject

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.

Specified by:

startUp in class CSEP545ServiceObject

Throws:

Exception

readyToServe

protected void readyToServe()
                     throws Exception

Description copied from class: CSEP545ServiceObject

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

Specified by:

readyToServe in class CSEP545ServiceObject

Throws:

Exception

refresh

public void refresh()
             throws RemoteException,
                    NotBoundException

Description copied from interface: CSEP545Service

Refresh all remote references used by this service. For easier automated testing recovery from failure.

Specified by:

refresh in interface CSEP545Service

Throws:

RemoteException

NotBoundException