CSCE3600 - Final

Question 1

groups sequences of tokens from from the lexical analysis phase into phrases

Answer 1

syntax analyzer or parser

Question 2

obtain tokens from lexical analyzer

Answer 2

syntax analyzer or parser

Question 3

determine the statement class

Answer 3

syntax analyzer or parser

Question 4

group tokens into statements

Answer 4

syntax analyzer or parser

Question 5

construct hierarchical structures called parse trees

Answer 5

syntax analyzer or parser

Question 6

takes input from the syntax analysis phase

Answer 6

semantic analysis

Question 7

takes input in form of parse tree and symbol table

Answer 7

semantic analysis

Question 8

determine if input has a well defined meaning

Answer 8

semantic analysis

Question 9

concerned with type checking and type coercion based on type rules

Answer 9

semantic analysis

Question 10

scans code from left-to-right, character-by-character, and groups into lexemes

Answer 10

lexical analyzer or scanner

Question 11

outputs a sequence of tokens to the syntax analyzer

Answer 11

lexical analyzer or scanner

Question 12

works in a uniprocessor environment only

Answer 12

interrupt

Question 13

generates a piece of data, put it into the buffer and start again

Answer 13

producer

Question 14

consuming the data (remove from buffer) one piece at a time

Answer 14

consumer

Question 15

try not to add data into the buffer if it’s full

Answer 15

producer problem

Question 16

try not to remove data from empty buffer

Answer 16

consumer problem

Question 17

int flag[2] = {FALSE, FALSE};
int turn = 0;
flag[i] = true;
turn = 1 - i;
while (flag[1 - i] && turn == 1 - i;
CSi;
flag[i] = FALSE;

Answer 17

peterson’s algorithm

Question 18

cannot affect or be affected by the execution of another process

Answer 18

independent process

Question 19

can affect or be affected by other processes executing in the system

Answer 19

cooperating process

Question 20

each process waiting for a message from the other process

Answer 20

deadlock

Question 21

two processes sending messages to each other while another process waits for a message

Answer 21

starvation

Question 22

what does atomic operation mean

Answer 22

non-interruptible

Question 23

three solutions to the critical-section problem

Answer 23

mutual exclusion, progress, and bounded waiting

Question 24

also called mutex locks

Answer 24

binary semaphores

Question 25

more restrictive version of semaphores that may take on a value of 0 or 1

Answer 25

binary semaphore

Question 26

used to write to a memory location and return its old value as a single atomic operation

Answer 26

test-and-set()

Question 27

only process that may enter critical section is one that finds shared variable set to 0; when done, resets shared variable to 0

Answer 27

test-and-set()

Question 28

refers to mutual exchanging of values of the variables

Answer 28

swap()

Question 29

exchanges contents of register with that of memory location

Answer 29

swap()

Question 30

when two or more processes try to use the same resource at the same time

Answer 30

race condition

Question 31

race conditions need

Answer 31

concurrency, shared object, change state

Question 32

a lock that causes a process/thread trying to acquire it to simply wait in a loop while repeatedly checking if the lock is available

Answer 32

spinlock

Question 33

where shared data is accessed

Answer 33

critical section

Question 34

ensure that when one process is executing in its critical section, no other process is allowed to execute

Answer 34

critical section problem

Question 35

if a page’s reference bit is set to 1

Answer 35

set its reference bit to zero and skip it

Question 36

if a pages reference bit is set to 0

Answer 36

select this page for replacement

Question 37

second chance clock algorithm always starts the search ___

Answer 37

from where the last search left off

Question 38

ordered list of pages accessed as process executes

Answer 38

reference string

Question 39

if page size is 100 what are the reference string of:

123, 215, 600, 1234, 76, 96

Answer 39

1, 2, 6, 12, 0, 0

Question 40

holds virtual address to physical address

Answer 40

page table

Question 41

memory is partitioned into chunks called

Answer 41

pages

Question 42

the oldest page in physical memory is the one selected for replacement

Answer 42

First-in First-out

Question 43

replace the page that will not be referenced for the longest time

Answer 43

belady’s min

Question 44

replace the page in memory that has not been accessed for the longest time

Answer 44

least recently used

Question 45

does not consider page usage

Answer 45

first-in first-out

Question 46

page that has been written to

Answer 46

dirty page

Question 47

before a dirty page can be replaced it must

Answer 47

be written to disk

Question 48

effective access time formula

Answer 48

( 1 - p ) * ( memory access time ) + p * ( page fault overhead )

Question 49

components that make up page fault overhead

Answer 49

fault service time, read page time, restart process time

Question 50

total memory space exists to satisfy a request, but it is not contiguous

Answer 50

external fragmentation

Question 51

allocated memory may be slightly larger than requested memory

Answer 51

internal fragmentation

Question 52

reduce external fragmentation

Answer 52

compaction

Question 53

shuffle memory contents to place all free memory together in one large block

Answer 53

compaction

Question 54

each whole list; choose block that comes closest to matching the needs of allocation

Answer 54

best fit

Question 55

scan the list for the first block that comes closes to matching the needs of allocation

Answer 55

first fit

Question 56

choose block that worst matches the request

Answer 56

worst fit

Question 57

scan the list for first block that comes closest to matching the needs of allocation

Answer 57

next fit