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Introduction. Token Based Mutual Exclusion Algorithms A unique token is shared among all sites. A site is allowed to enter critical section if it possesses the token.Types of Token based algorithm:Broad Cast Non BroadCast. Suzuki Kasami's Algorithm. If a site needs to enter into critical sec
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1. Comparison between Suzuki Kasami’s and Raymond’s Tree Algorithm -Sagar Panchariya
2. Introduction Token Based Mutual Exclusion Algorithms
A unique token is shared among all sites. A site is allowed to enter critical section if it possesses the token.
Types of Token based algorithm:
Broad Cast
Non BroadCast
3. Suzuki Kasami’s Algorithm If a site needs to enter into critical section and if does not have a token it broad cast request to all the other site.
On receiving request if a site has token if the token is idle, i.e. site is not executing critical section it sends the PRIVILEDGE message containing the token the requesting site.
Each site contains a requesting site array R[requesting sequences]. Token maintains LN array[executed sequences] and token queue
4. Raymond’s Tree Algorithm Site does not broad cast it sends a request along the directed edge to its holder.
Site can send request along the directed edge only once. Every site maintains a request array of Processes requesting CS.
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.
5. Performance Parameters for Mutual Exclusion Algorithm Number of messages per CS entry
Synchronization delay: Time required when one site leaves CS and another enter CS.
Response Time: Is the time interval a site waits its CS execution to be over after request has been sent.
Throughput=1/(sd+E), where sd is average synchronization delay, E is average CS execution time
6. Parameters I kept as fixed while measurements: Number of CS executions:100
Message delay:1-9
CS execution time:1-9
Parameters I varied:
Number of nodes 30,50,100
load (number of process simultaneously requesting CS). 1p,1/2p,full load.