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Class JavaGroups.JavaStack.Protocols.UNICAST 

java.lang.Object
   |
   +----JavaGroups.JavaStack.Protocol
           |
           +----JavaGroups.JavaStack.Protocols.UNICAST
public class UNICAST
extends Protocol
implements AckSenderWindow. RetransmitCommand
Reliable unicast layer. Uses acknowledgement scheme similar to TCP to provide lossless transmission of unicast messages (for reliable multicast see NAKACK layer). When a message is sent to a peer for the first time, we add the pair in the hashtable (peer address is the key). All messages sent to that peer will be added to hashtable.peer_addr.sent_msgs. When we receive a message from a peer for the first time, another entry will be created and added to the hashtable (unless already existing). Msgs will then be added to hashtable.peer_addr.received_msgs.

This layer is used to reliably transmit point-to-point messages, that is, either messages sent to a single receiver (vs. messages multicast to a group) or for example replies to a multicast message. The sender uses an AckSenderWindow which retransmits messages for which it hasn't received an ACK, the receiver uses AckReceiverWindow which keeps track of the lowest seqno received so far, and keeps messages in order.

Constructor Index

o UNICAST()

Method Index

o Down(Event)
An event is to be sent down the stack.
o GetName()
All protocol names have to be unique !
o Retransmit(long, Message, int)
Called by AckSenderWindow to resend messages for which no ACK has been received yet
o SetProperties(Properties)
Configures the protocol initially.
o Up(Event)
An event was received from the layer below.

Constructors

o UNICAST 
 public UNICAST()

Methods

o GetName 
 public String GetName()
All protocol names have to be unique !

Overrides:
GetName in class Protocol
o SetProperties 
 public boolean SetProperties(Properties props)
Configures the protocol initially.

Overrides:
SetProperties in class Protocol
o Up 
 public void Up(Event evt)
An event was received from the layer below.

Overrides:
Up in class Protocol
o Down 
 public void Down(Event evt)
An event is to be sent down the stack.

Overrides:
Down in class Protocol
o Retransmit 
 public void Retransmit(long seqno,
                        Message msg,
                        int num_tries)
Called by AckSenderWindow to resend messages for which no ACK has been received yet 

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