1. Raymond Exclusive Algorithm
Lakshmi Nannapaneni

2. Contents Introduction Experimental setup Result Analysis Conclusion
Future Work

3. Introduction Non-broadcast algorithm.
Sends request along the directed edge to its holder.
Each site maintains a request queue for storing requests.
Token is released when the token is idle with the process and send with a PRIVILEDGE message along the edge.
If the sites id is top of its request Q then the site can enter critical section.

4. Experimental Setup
Average of total number of messages sent for each critical section execution.
Results taken by varying critical section execution of load, half load, full load for the nodes from 10 to 100
Topologies : Chain, Tree, Star

5. Result Analysis: Star topology
Messages
Nodes

6. Result Analysis: Tree topology
Messages
Nodes

7. Result Analysis: Chain topology
Messages
Nodes

8. Conclusion
The worst case occurs at low loads and in chain topology which increases the diameter of the network used.
However this is improved under full load condition.

9. Future Work
Future work includes testing the performance of the algorithm on chain of large number of nodes in thousands range to get the accurate result.
The implementation can be enhanced to make Raymond Tree work for completely connected graphs in which a spanning tree can be formed and algorithm can be applied on that.

10. Code Defense
// sending token to the process that requests to enter into critical section
public synchronized void sendTokenToProcess(int pid, Token t) {
if(hasToken) {
this.hasToken=false;
this.holder=pid;
Parent.p[pid].setHolder(pid);
Parent.p[pid].setHasToken(true);
Parent.p[pid].hasSentRequest=false;
System.out.println("Token sent from P"+id+" to site P"+pid);
System.out.println("******* NOW THE TOKEN HOLDER IS p"+pid+ "------*******"); }