com.distributed.api
Class Environment

java.lang.Object
  |
  +--com.distributed.api.Environment

All Implemented Interfaces:

MessageReceiverListener

public class Environment

extends java.lang.Object

implements MessageReceiverListener

Defines all methods that can be used by any distributed appication process

Field Summary

static int	CONTROL_PORT Default port number
int	N Number of processes in distributed system

Constructor Summary

Environment(java.lang.String filename, EnvironmentListener up)
establishes the connections with other processes & starts listening on the channel

Method Summary

protected void	allSnapsReceived(int sendsnapto, java.lang.String chanstate) Sends the global picture of distributed system to the requesting process
protected void	appendState(java.lang.String s) Appends to present global state
Clock	getClock() Returns the internal clock of the application process
void	getConsensus(int val) Proposes consensus value of this application process & achieves consensus
int	getPid() Returns process id of the application process in distributed system
protected EnvironmentListener	getUserProcess() Returns EnvironmentListener of application process
void	holdElection() Does the election using protocol 1
void	holdElection2() Does the election using protocol 2
void	messageReceived(Message m) Handles both control & application messages
void	releaseLock() Exits critical sections & releases lock
void	requestCsEntry() Enters the application process in critical section
protected void	saveLocalState(int source, int sendsnapto) Saves local state & turns red
void	sendTo(int despid, java.lang.String messgtext) Sends messgtext message to particular destination
protected void	sendTo(int despid, java.lang.String messgtext, int messgtype, boolean clock_required, int clock_type) Environment uses this method to send message to a particular destination
void	sendToAllNeighbours(java.lang.String messgtext) Broadcasts message
protected void	sendToAllNeighbours(java.lang.String messgtext, int messgtype, boolean clock_required, int clock_type) Used by Environment to broadcast messages
java.lang.String	takeSnapshot() Returns global picture of the entire distributed system
void	terminate() Closes all connection

Methods inherited from class java.lang.Object

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

Field Detail

CONTROL_PORT

public static final int CONTROL_PORT

Default port number

See Also:

Constant Field Values

N

public int N

Number of processes in distributed system

Constructor Detail

Environment

public Environment(java.lang.String filename,
                   EnvironmentListener up)
            throws java.lang.Exception

establishes the connections with other processes & starts listening on the channel

Parameters:

filename - configuration file of the network

up - application process Environment listener

Method Detail

allSnapsReceived

protected void allSnapsReceived(int sendsnapto,
                                java.lang.String chanstate)

Sends the global picture of distributed system to the requesting process

Parameters:

sendsnapto - process to which snapshot has to be sent

chanstate - state of the channel

appendState

protected void appendState(java.lang.String s)

Appends to present global state

Parameters:

s - string to be appended to global state

getClock

public Clock getClock()

Returns the internal clock of the application process

getConsensus

public void getConsensus(int val)

Proposes consensus value of this application process & achieves consensus

Parameters:

val - value to be proposed

getPid

public int getPid()

Returns process id of the application process in distributed system

getUserProcess

protected EnvironmentListener getUserProcess()

Returns EnvironmentListener of application process

holdElection

public void holdElection()

Does the election using protocol 1

holdElection2

public void holdElection2()

Does the election using protocol 2

messageReceived

public void messageReceived(Message m)

Handles both control & application messages

Specified by:

messageReceived in interface MessageReceiverListener

Parameters:

m - Message that has been received

releaseLock

public void releaseLock()

Exits critical sections & releases lock

requestCsEntry

public void requestCsEntry()

Enters the application process in critical section

saveLocalState

protected void saveLocalState(int source,
                              int sendsnapto)

Saves local state & turns red

Parameters:

source - process from which the marker was received

sendsnapto - process to which snapshot has to be sent

sendTo

public void sendTo(int despid,
                   java.lang.String messgtext)

Sends messgtext message to particular destination

Parameters:

messgtext - message to be sent

sendTo

protected void sendTo(int despid,
                      java.lang.String messgtext,
                      int messgtype,
                      boolean clock_required,
                      int clock_type)

Environment uses this method to send message to a particular destination

Parameters:

messgtext - message to be sent

messgtype - type of the message

clock_required - says whether clock is required or not

clock_type - type of clock(lamport or vector)

sendToAllNeighbours

public void sendToAllNeighbours(java.lang.String messgtext)

Broadcasts message

Parameters:

messgtext - message to be broadcasted

sendToAllNeighbours

protected void sendToAllNeighbours(java.lang.String messgtext,
                                   int messgtype,
                                   boolean clock_required,
                                   int clock_type)

Used by Environment to broadcast messages

Parameters:

messgtext - message to be sent

messgtype - type of the message

clock_required - says whether clock is required or not

clock_type - type of clock(lamport or vector)

takeSnapshot

public java.lang.String takeSnapshot()

Returns global picture of the entire distributed system

terminate

public void terminate()

Closes all connection