AMMAN ARAB UNIVERSITY

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Q$3.$ Answer the following short questions:

A$)$ List three advantages of threads

B$)$ What is the purpose of the Dispatcher?

C$)$ Some CPU scheduling algorithms are sets of other CPU scheduling algorithms holds between RR and FCFS algorithms?

$4.$ Suppose we have producer and consumer processes. The producer produces them into a $($queue$)$ buffer owned by the consumer, while the consumer consur buffer in FIFO order. Each item requires $1$ time quantum to be produced and be consumed. The buffer is initially empty and has a maximum size of $3.$ consumer processes are well$-$synchronized using semaphores.

Consider the case when we run three producers $P_1,P_2,$ and $P_3,$ and one consu the processes are runnable starting at time zero. Answer the following quest

A$.$ If Round$-$Robin Scheduling used to execute those processes, how ma process produce and consume at the end of ${10}^{th}$ time quantum? Assume queue order is $P_1,P_2,P_3,C_1.$

B$.$ If Priority Scheduling is used to execute the processes and the priorities follows: $P(C1)=4,P(P3)=3,P(P2)=2,$ and $P(P1)=1.$ How many ite produce and consume at the end of ${10}^{th}$ time quantum? Assume that higher priority. Explain your answer.

Consider the following two concurrently running processes $P0$ and $P$ ariables A$,$ B$,$ C$,$ X$,$ Y$,$ and Z$.$

P$0$: $-$

$C=1$;

$A=4$;

$B=5$;

$x=A+B$;

$Y=x-C$;

end.

P$1$: $,A=3$;

$B=2$;

$Z=x+Y$;

end.

the code of $P0$ and $P1$ by adding synchronization variable$($s$)$ and st $Z$ equals to $15.$

onsider the initial value of the synchronization variable$($s$)$ "Semapl

FDCD$-1,$ Rev. b

Ref.: Deans' Council Session $($I$3/2019-2020),$ Decision No$..23,$ Date: $10/02/2020$

Quality Assurance Council Session $(3$D$/2019-2020),$ Decision No$..$ D$4.$ Date: $26/$P$\text{'}$