Objective

This assignment will irneduce you so CPU scheduling.

Specificatious

You are to simulate the execution of processes by a computer system with a large

mensocy, cese terminal per user, a CPU, and one disk drive. Each process will be

described by its class $($REaL$-$TINE or IMTRacTIVE$)$ and its start time followed by a

sequence of resource requests.

These resources requests will inclade CPU requests $($CPU$),$ disk reads $($DIgK$)$ and

terminal accesses $($TTY$).$ In addition, all real$-$time processes will have a DRADLINX, by

which they must complete.

Your input will be a sequence of pairs as in:

All time will be expeessed in milliseconds.

Your program should maintain sepsate ready queues for real$-$timse and interactive

processes and give absolute priority to real$-$time processes over interactive processes:

a$)$ Your scheduler should never allocate the CPU to an interactive process as long as

there are one or more real$-$time processes in the ready state.

b$)$ When a real$-$tine process returns to the ready queue and finds that the CPU is

currently allocated to an inseractive process, the scheduler should take the CPU away

from the interactive proess and give it to the real$-$time process. The pre$-$empted

process should retum to the end of the ready qucue for inderactive processes. When

this is the case your program should updaxe the duration of the CPU request by

suberacting from the origial duration the time the proess, has already spent in the

runuing state.

Disk scheduling will be strictly first$-$come fisst$-$sened $($FCFS$)$ without any distinction of

proess classes.

To simplify your life, we will also assume that:

a$)$ there is enough mensory spoce for all processes,

b$)$ context switch times can be neglectod,

c$)$ weer think times are iscloded in the tenvinal access times, and

d$)$ each process reads and writes to a different terminal.

Your program should read its input file name through input redirection as in:

$\frac{.}{a}.$out $<mn\; id="EditorElement\_8083026">1</mn>$ input. $txt$

If by accident, two resources allocations need to be made at the same timb, you should

allocate the CPU first thea the disk and then the terminals.

Your program should have one process table with one entry per process coetaining a

process sequence number, the process class, its poocess arrival time and its current satus

$($READY$,$ RCRNIVG, WAITING$).$

It should point out one line of output every time a process starts of temvinates. This line

should inclode the process sequence number, its class and the current simulated time in

millikeconds.

Whea all the processes in your input stream have coupleted, your simulator should point

a sumwary report listing:

a$)$ the number of real$-$time processes that have completed,

b$)$ the percentage of real$-$tinse processes that missed their deadline,

c$)$ the number of interactive processes that have completed,

d$)$ the total number of disk accesses,

e$)$ the average duration of a disk access $($including the waiting time in the disk queue$),$

f$)$ the total timse elapoed simoe the start of the first process,

g$)$ the CPU and disk utilizations, that is$,$ the fraction of time the CPU or the disk was

buxy.

Important

Your program should start by a block of oomments containing your name, the

course number, the dac date and a very short description of the assignmeat. It

should coevain functions and these functions should have arguments.

Fach function should start by a very brief description of the task it perfocnes.

Fach variable definition should be followed by a convent describing the function

of the variable.

All numerical constants should be specified using symbolic constants defined at

the begiming of the progran.

All the source code files, executable code files, readme files, and all the

documentation should subenitted electronically through Brightespace.