Concurrent And Distributed Systems

Part 1. For this part, you may use wait-chain diagrams as introduced in Chapter 7 to justify your answer. If you like, you can use some other notation that allows you to detect deadlock but you must still justify your answer.

i)There are 3 resources, G, H and J, each of which can be acquired and released (that is, locked and unlocked). There is one resource-usertype or class, Q. Each instance of Qrepeatedly executes this sequence:

It acquires resource G, and then resource H.

It then releases G and acquires resource J.

It then releases H and acquires G.

It then releases G and J.

How many instances of Qdoes it take to create deadlock?

ii)There are 5 resources, A, B, F, G, I, each of which can be acquired and released. There are two resource-user (or thread) types Sand T.

Each instance of Srepeatedly executes this sequence:

It acquires I, then A, and then G.

It releases A and G.

It acquires B.

It releases I and then B.

Each instance of Trepeatedly executes this sequence:

It acquires G and then F

It releases G

It acquires A

It releases F and then A

1. How many instances of Sdoes it take to create deadlock if there are no instances of T?
2. How many instances of Tdoes it take to create deadlock if there are no instance of S?
3. There are instances of Sand of T. How many instances of Sand how many instances of Tdoes it take to create deadlock?

Part 2:What is each node’s vectorclock value at the end? P1’s clock starts at (1, 0, 0). P2’s clock starts at (0, 1, 0). P3’s clock starts at (0, 0, 1).