org.apache.giraph.examples.utils

Class BrachaTouegDeadlockVertexValue

java.lang.Object

org.apache.giraph.examples.utils.BrachaTouegDeadlockVertexValue

All Implemented Interfaces:

org.apache.hadoop.io.Writable

public class BrachaTouegDeadlockVertexValue
extends Object
implements org.apache.hadoop.io.Writable

Vertex value used for the Bracha-Toueg Dealock algorithm

Field Summary

Fields

Modifier and Type	Field and Description
static Long	INVALID_ID Invalid ID

Constructor Summary

Constructors

Constructor and Description
BrachaTouegDeadlockVertexValue() Default constructor
BrachaTouegDeadlockVertexValue(HashMap<Long,ArrayList<Long>> requests) Parametrized constructor

Method Summary

Modifier and Type	Method and Description
void	addParent(Long parentId) add a parent id into the list of parents kept at the vertex side
Long	getIdWithInHoldAck()
Long	getIdWithInHoldDone()
int	getNumOfRequests(org.apache.hadoop.io.LongWritable tag) This function retrieves the number of pending requests for the specified tag.
ArrayList<Long>	getParents()
boolean	hasPendingRequests()
boolean	isFree()
boolean	isNotified()
boolean	isWaitingForMessage(Long type)
void	readFields(DataInput input)
void	receivedMessage(Long id, Long type) Each time a message is received, it has to be removed from the queue that keeps track of the waited messages.
void	removeRequest(org.apache.hadoop.io.LongWritable tag, org.apache.hadoop.io.LongWritable targetId) remove the expected request from the edge on which the message arrived
void	setFree() the vertex is free from deadlocks
void	setIdWithInHoldAck(Long id)
void	setIdWithInHoldDone(Long doneId)
void	setNotified() the vertex got a notification
String	toString()
void	waitForMessage(Long id, Long type) Add a new message that must be expected by the node
void	write(DataOutput output)

Methods inherited from class java.lang.Object

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

Field Detail

INVALID_ID

public static final Long INVALID_ID

Invalid ID

Constructor Detail

BrachaTouegDeadlockVertexValue

public BrachaTouegDeadlockVertexValue()

Default constructor

BrachaTouegDeadlockVertexValue

public BrachaTouegDeadlockVertexValue(HashMap<Long,ArrayList<Long>> requests)

Parametrized constructor

Parameters:

requests - number of requests needed to consider the node free

Method Detail

readFields

public void readFields(DataInput input)
                throws IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

IOException

write

public void write(DataOutput output)
           throws IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

IOException

isFree

public boolean isFree()

Returns:

true if free, false otherwise

setFree

public void setFree()

the vertex is free from deadlocks

isNotified

public boolean isNotified()

Returns:

true if the vertex was notified, false otherwise

setNotified

public void setNotified()

the vertex got a notification

hasPendingRequests

public boolean hasPendingRequests()

Returns:

false if no pending requests have to be still processed to continue the computation

removeRequest

public void removeRequest(org.apache.hadoop.io.LongWritable tag,
                          org.apache.hadoop.io.LongWritable targetId)

remove the expected request from the edge on which the message arrived

Parameters:

tag - tag of the edge

targetId - target Id to which the edge points

getNumOfRequests

public int getNumOfRequests(org.apache.hadoop.io.LongWritable tag)

This function retrieves the number of pending requests for the specified tag. Because of the N-out-of-M semantic, each time a GRANT is received on an edge, the number of requests is reduced for the tag which the edge is part of.

Parameters:

tag - tag related to the requests to be verified

Returns:

number of requests pending for the tag provided

waitForMessage

public void waitForMessage(Long id,
                           Long type)

Add a new message that must be expected by the node

Parameters:

id - ID of the node from which the messages is expected

type - type of message that is awaited

receivedMessage

public void receivedMessage(Long id,
                            Long type)

Each time a message is received, it has to be removed from the queue that keeps track of the waited messages.

Parameters:

id - ID of the node from which the messages is expected

type - type of message that is awaited

isWaitingForMessage

public boolean isWaitingForMessage(Long type)

Parameters:

type - type of message to check

Returns:

boolean true if waiting the message type, false otherwise

addParent

public void addParent(Long parentId)

add a parent id into the list of parents kept at the vertex side

Parameters:

parentId - vertex id of the parent

getParents

public ArrayList<Long> getParents()

Returns:

list of parent IDs collected

getIdWithInHoldAck

public Long getIdWithInHoldAck()

Returns:

the id waiting for an ACK message

setIdWithInHoldAck

public void setIdWithInHoldAck(Long id)

Parameters:

id - the id to set

getIdWithInHoldDone

public Long getIdWithInHoldDone()

Returns:

the id waiting for an DONE message

setIdWithInHoldDone

public void setIdWithInHoldDone(Long doneId)

Parameters:

doneId - the id to set

toString

public String toString()

Overrides:

toString in class Object