n n n n n Operating System Concepts - 10th n Philosophers spend their lives alternating thinking and eating Don't interact with their neighbors, occasionally try to pick up 2 chopsticks (one at a time) to eat from bowl Need both to eat, then release both when done In the case of 5 philosophers Shared data (RICE Bowl of rice (data set) Semaphore chopstick [5] initialized to 1 7.0 Semaphore Solution The structure of Philosopher i: while (true) { Dining-Philosophers Problem Algorithm wait (chopstick [i]); wait (chopStick [ (i+1) % 5] ); /* eat for awhile */ signal (chopstick [i]); signal (chopstick [ (i + 1) % 5] ); /* think for awhile */ Silberschatz, Galvin and Gagne ©20 } What is the problem with this algorithm?

Not an exam. Just review for me. For each function f(n) below give an asymptoic upper bound using big-Oh notation. You should give the tighest bound (ie. smallest bound) possible and simplify the expression.  Explain step by step how you your answers. Use signma notation to prove your answers if you can     I attached the answers for question 3 and 4 for your reference so you can check your work but explain how you got those answers.  I dont have the answer key for 1 so please try your best on that.

We can implement requests to the waiter as either a queue of requests or as a periodic retry of a request. With a queue, requests are handled in the order they are received. Th e problem with using the queue is that we may not always be able to service the philosopher whose request is at the head of the queue (due to the unavailability of resources). Describe a scenario with 5 philosophers where a queue is provided, but service is not granted even though there are forks available for another philosopher (whose request is deeper in the queue) to eat.If we implement requests to the waiter by periodically repeating our request until the resources become available, will this solve the problem described in the above Exercise? Explain.

Show that each argument is not valid by finding a truth assignment of the variables that makes the hypotheses true, but the conclusion false. (Hint: fill out a truth table if you have trouble finding an assignment.) PVr (a) P^r