1690 + Mcqs in Operating System Page 31 McqOptions

1501.	Which of the following concurrency control protocols ensure both conflict serializability and freedom from deadlock ? I) 2-phase locking II) Timestamp ordering
A.	I only
B.	II only
C.	Both I and II
D.	Neither I nor II
Answer» C. Both I and II

Discussion

1502.	The shrinking phase is a phase in which :
A.	A transaction may obtain locks, but does not release any
B.	A transaction may obtain locks, and releases a few or all of them
C.	A transaction may release locks, but does not obtain any new locks
D.	A transaction may release locks, and does obtain new locks
Answer» D. A transaction may release locks, and does obtain new locks

Discussion

1503.	The growing phase is a phase in which :
A.	A transaction may obtain locks, but does not release any
B.	A transaction may obtain locks, and releases a few or all of them
C.	A transaction may release locks, but does not obtain any new locks
D.	A transaction may release locks, and does obtain new locks
Answer» B. A transaction may obtain locks, and releases a few or all of them

Discussion

1504.	The two phase locking protocol consists of :
A.	growing & shrinking phase
B.	shrinking & creation phase
C.	creation & growing phase
D.	destruction & creation phase
Answer» B. shrinking & creation phase

Discussion

1505.	A locking protocol is one that :
A.	governs how locks are acquired
B.	governs how locks are released
C.	governs how locks are acquired and released
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

1506.	Serializable schedules are ones where :
A.	concurrent execution of transactions is equivalent to the transactions executed serially
B.	the transactions can be carried out one after the other
C.	a valid result occurs after execution transactions
D.	none of the mentioned
Answer» B. the transactions can be carried out one after the other

Discussion

1507.	Consider a transaction T1 that committed prior to checkpoint. The record appears in the log before the record. Any modifications made by T1 must have been written to the stable storage either with the checkpoint or prior to it. Thus at recovery time:
A.	There is a need to perform an undo operation on T1
B.	There is a need to perform a redo operation on T1
C.	There is no need to perform an undo and redo operation on T1
D.	All of the mentioned
Answer» D. All of the mentioned

Discussion

1508.	The system periodically performs checkpoints that consists of the following operation(s) :
A.	Putting all the log records currently in main memory onto stable storage
B.	putting all modified data residing in main memory onto stable storage
C.	putting a log record onto stable storage
D.	all of the mentioned
Answer» E.

Discussion

1509.	The undo and redo operations must be _________ to guarantee correct behaviour, even if a failure occurs during recovery process.
A.	idempotent
B.	easy
C.	protected
D.	all of the mentioned
Answer» B. easy

Discussion

1510.	An actual update is not allowed to a data item :
A.	before the corresponding log record is written out to stable storage
B.	after the corresponding log record is written out to stable storage
C.	until the whole log record has been checked for inconsistencies
D.	all of the mentioned
Answer» B. after the corresponding log record is written out to stable storage

Discussion

1511.	In the write ahead logging a _____ is maintained.
A.	a memory
B.	a system
C.	a disk
D.	a log record
Answer» E.

Discussion

1512.	Write ahead logging is a way :
A.	to ensure atomicity
B.	to keep data consistent
C.	that records data on stable storage
D.	all of the mentioned
Answer» E.

Discussion

1513.	The state of the data accessed by an aborted transaction must be restored to what it was just before the transaction started executing. This restoration is known as ________ of transaction.
A.	safety
B.	protection
C.	roll – back
D.	revert – back
Answer» D. revert – back

Discussion

1514.	A terminated transaction that has completed its execution successfully is ____________ otherwise it is __________
A.	committed, destroyed
B.	aborted, destroyed
C.	committed, aborted
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

1515.	A collection of instructions that performs a single logical function is called :
A.	transaction
B.	operation
C.	function
D.	all of the mentioned
Answer» B. operation

Discussion

1516.	If no process is suspended, the signal operation :
A.	puts the system into a deadlock state
B.	suspends some default process’ execution
C.	nothing happens
D.	the output is unpredictable
Answer» D. the output is unpredictable

Discussion

1517.	The process invoking the wait operation is :
A.	suspended until another process invokes the signal operation
B.	waiting for another process to complete before it can itself call the signal operation
C.	stopped until the next process in the queue finishes execution
D.	none of the mentioned
Answer» B. waiting for another process to complete before it can itself call the signal operation

Discussion

1518.	The operations that can be invoked on a condition variable are :
A.	wait & signal
B.	hold & wait
C.	signal & hold
D.	continue & signal
Answer» B. hold & wait

Discussion

1519.	The monitor construct ensures that :
A.	only one process can be active at a time within the monitor
B.	n number of processes can be active at a time within the monitor (n being greater than 1)
C.	the queue has only one process in it at a time
D.	all of the mentioned
Answer» B. n number of processes can be active at a time within the monitor (n being greater than 1)

Discussion

1520.	A procedure defined within a ________ can access only those variables declared locally within the _______ and its formal parameters.
A.	process, semaphore
B.	process, monitor
C.	semaphore, semaphore
D.	monitor, monitor
Answer» E.

Discussion

1521.	A monitor is characterized by :
A.	a set of programmer defined operators
B.	an identifier
C.	the number of variables in it
D.	all of the mentioned
Answer» B. an identifier

Discussion

1522.	A monitor is a type of :
A.	semaphore
B.	low level synchronization construct
C.	high level synchronization construct
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

1523.	A deadlock free solution to the dining philosophers problem :
A.	necessarily eliminates the possibility of starvation
B.	does not necessarily eliminate the possibility of starvation
C.	eliminates any possibility of any kind of problem further
D.	None of the mentioned
Answer» C. eliminates any possibility of any kind of problem further

Discussion

1524.	The dining – philosophers problem will occur in case of :
A.	5 philosophers and 5 chopsticks
B.	4 philosophers and 5 chopsticks
C.	3 philosophers and 5 chopsticks
D.	6 philosophers and 5 chopsticks
Answer» B. 4 philosophers and 5 chopsticks

Discussion

1525.	To ensure difficulties do not arise in the readers – writers problem, _______ are given exclusive access to the shared object.
A.	readers
B.	writers
C.	readers and writers
D.	none of the mentioned
Answer» C. readers and writers

Discussion

1526.	In the bounded buffer problem :
A.	there is only one buffer
B.	there are n buffers ( n being greater than one but finite)
C.	there are infinite buffers
D.	there are infinite buffers
Answer» C. there are infinite buffers

Discussion

1527.	In the bounded buffer problem, there are the empty and full semaphores that :
A.	count the number of empty and full buffers
B.	count the number of empty and full memory spaces
C.	count the number of empty and full queues
D.	none of the mentioned
Answer» B. count the number of empty and full memory spaces

Discussion

1528.	The bounded buffer problem is also known as :
A.	Readers – Writers problem
B.	Dining – Philosophers problem
C.	Producer – Consumer problem
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

1529.	Spinlocks are intended to provide __________ only.
A.	Mutual Exclusion
B.	Bounded Waiting
C.	Aging
D.	Progress
Answer» C. Aging

Discussion

1530.	Semaphores are mostly used to implement :
A.	System calls
B.	IPC mechanisms
C.	System protection
D.	None of the mentioned
Answer» C. System protection

Discussion

1531.	A binary semaphore is a semaphore with integer values :
A.	1
B.	-1
C.	0
D.	8
Answer» B. -1

Discussion

1532.	At a particular time of computation the value of a counting semaphore is 7.Then 20 P operations and 15 V operations were completed on this semaphore.The resulting value of the semaphore is : (GATE 1987)
A.	42
B.	2
C.	7
D.	12
Answer» C. 7

Discussion

1533.	A mutex :
A.	is a binary mutex
B.	must be accessed from only one process
C.	can be accessed from multiple processes
D.	None of the mentioned
Answer» C. can be accessed from multiple processes

Discussion

1534.	The two kinds of semaphores are :
A.	mutex & counting
B.	binary & counting
C.	counting & decimal
D.	decimal & binary
Answer» C. counting & decimal

Discussion

1535.	A semaphore :
A.	is a binary mutex
B.	must be accessed from only one process
C.	can be accessed from multiple processes
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

1536.	What will happen if a non-recursive mutex is locked more than once ?
A.	Starvation
B.	Deadlock
C.	Aging
D.	Signaling
Answer» C. Aging

Discussion

1537.	The code that changes the value of the semaphore is :
A.	remainder section code
B.	non – critical section code
C.	critical section code
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

1538.	If the semaphore value is negative :
A.	its magnitude is the number of processes waiting on that semaphore
B.	it is invalid
C.	no operation can be further performed on it until the signal operation is performed on it
D.	none of the mentioned
Answer» B. it is invalid

Discussion

1539.	The signal operation of the semaphore basically works on the basic _______ system call.
A.	continue()
B.	wakeup()
C.	getup()
D.	start()
Answer» C. getup()

Discussion

1540.	The main disadvantage of spinlocks is that :
A.	they are not sufficient for many process
B.	they require busy waiting
C.	they are unreliable sometimes
D.	they are too complex for programmers
Answer» C. they are unreliable sometimes

Discussion

1541.	Spinlocks are :
A.	CPU cycles wasting locks over critical sections of programs
B.	Locks that avoid time wastage in context switches
C.	Locks that work better on multiprocessor systems
D.	All of the mentioned
Answer» E.

Discussion

1542.	The two atomic operations permissible on semaphores are :
A.	wait
B.	stop
C.	hold
D.	none of the mentioned
Answer» B. stop

Discussion

1543.	Semaphore is a/an _______ to solve the critical section problem.
A.	hardware for a system
B.	special program for a system
C.	integer variable
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

1544.	The TestAndSet instruction is executed :
A.	after a particular process
B.	periodically
C.	atomically
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

1545.	An un-interruptible unit is known as :
A.	single
B.	atomic
C.	static
D.	none of the mentioned
Answer» C. static

Discussion

1546.	In the bakery algorithm to solve the critical section problem :
A.	each process is put into a queue and picked up in an ordered manner
B.	each process receives a number (may or may not be unique) and the one with the lowest number is served next
C.	each process gets a unique number and the one with the highest number is served next
D.	each process gets a unique number and the one with the lowest number is served next
Answer» C. each process gets a unique number and the one with the highest number is served next

Discussion

1547.	A minimum of _____ variable(s) is/are required to be shared between processes to solve the critical section problem.
A.	One
B.	Two
C.	Three
D.	Four
Answer» C. Three

Discussion

1548.	Bounded waiting implies that there exists a bound on the number of times a process is allowed to enter its critical section :
A.	after a process has made a request to enter its critical section and before the request is granted
B.	when another process is in its critical section
C.	before a process has made a request to enter its critical section
D.	none of the mentioned
Answer» B. when another process is in its critical section

Discussion

1549.	Mutual exclusion implies that :
A.	if a process is executing in its critical section, then no other process must be executing in their critical sections
B.	if a process is executing in its critical section, then other processes must be executing in their critical sections
C.	if a process is executing in its critical section, then all the resources of the system must be blocked until it finishes execution
D.	none of the mentioned
Answer» B. if a process is executing in its critical section, then other processes must be executing in their critical sections

Discussion

1550.	The following three conditions must be satisfied to solve the critical section problem :
A.	Mutual Exclusion
B.	Progress
C.	Bounded Waiting
D.	All of the mentioned
Answer» E.

Discussion

Explore topic-wise MCQs in Technical Programming.

Which of the following concurrency control protocols ensure both conflict serializability and freedom from deadlock ? I) 2-phase locking II) Timestamp ordering

The shrinking phase is a phase in which :

The growing phase is a phase in which :

The two phase locking protocol consists of :

A locking protocol is one that :

Serializable schedules are ones where :

Consider a transaction T1 that committed prior to checkpoint. The record appears in the log before the record. Any modifications made by T1 must have been written to the stable storage either with the checkpoint or prior to it. Thus at recovery time:

The system periodically performs checkpoints that consists of the following operation(s) :

The undo and redo operations must be _________ to guarantee correct behaviour, even if a failure occurs during recovery process.

An actual update is not allowed to a data item :

In the write ahead logging a _____ is maintained.

Write ahead logging is a way :

The state of the data accessed by an aborted transaction must be restored to what it was just before the transaction started executing. This restoration is known as ________ of transaction.

A terminated transaction that has completed its execution successfully is ____________ otherwise it is __________

A collection of instructions that performs a single logical function is called :

If no process is suspended, the signal operation :

The process invoking the wait operation is :

The operations that can be invoked on a condition variable are :

The monitor construct ensures that :

A procedure defined within a ________ can access only those variables declared locally within the _______ and its formal parameters.

A monitor is characterized by :

A monitor is a type of :

A deadlock free solution to the dining philosophers problem :

The dining – philosophers problem will occur in case of :

To ensure difficulties do not arise in the readers – writers problem, _______ are given exclusive access to the shared object.

In the bounded buffer problem :

In the bounded buffer problem, there are the empty and full semaphores that :

The bounded buffer problem is also known as :

Spinlocks are intended to provide __________ only.

Semaphores are mostly used to implement :

A binary semaphore is a semaphore with integer values :

At a particular time of computation the value of a counting semaphore is 7.Then 20 P operations and 15 V operations were completed on this semaphore.The resulting value of the semaphore is : (GATE 1987)

A mutex :

The two kinds of semaphores are :

A semaphore :

What will happen if a non-recursive mutex is locked more than once ?

The code that changes the value of the semaphore is :

If the semaphore value is negative :

The signal operation of the semaphore basically works on the basic _______ system call.

The main disadvantage of spinlocks is that :

Spinlocks are :

The two atomic operations permissible on semaphores are :

Semaphore is a/an _______ to solve the critical section problem.

The TestAndSet instruction is executed :

An un-interruptible unit is known as :

In the bakery algorithm to solve the critical section problem :

A minimum of _____ variable(s) is/are required to be shared between processes to solve the critical section problem.

Bounded waiting implies that there exists a bound on the number of times a process is allowed to enter its critical section :

Mutual exclusion implies that :

The following three conditions must be satisfied to solve the critical section problem :

A terminated transaction that has completed its execution successfully is __ otherwise it is

A procedure defined within a __ can access only those variables declared locally within the _ and its formal parameters.