Each connection arriving at multi threaded servers via network is generally

is kept in a normal queue and then sent to the blocking queue from where it is dequeued

is directly put into the blocking queue

is wrapped as a task and passed on to a thread pool

is kept in a normal queue and then sent to the blocking queue from where it is dequeued

Thread pools are useful when

when we need to limit the number of threads running in the application as a whole

when we need to limit the number of threads running in the application at the same time

when we need to limit the number of threads running in the application as a whole

when we need to arrange the ordering of threads

In most cases, if a process is sent a signal while it is executing a system call

the system call will continue execution and the signal will be ignored completely

the system call is interrupted by the signal, and the signal handler comes in

the signal has no effect until the system call completes

The usefulness of signals as a general inter process communication mechanism is limited because

they do not work between processes

they cannot carry information directly

When a process blocks the receipt of certain signals?

the signals are received until they are unblocked

the signals are received by the process once they are delivered

Signals that occur at the same time, are presented to the process

one at a time, in a particular order

one at a time, in no particular order

Which of the following is not TRUE?

each signal is maintained by a single bit

processes may send each other signals

kernel may send signals internally

a field is updated in the signal table when the signal is sent

each signal is maintained by a single bit

Cancellation point is the point where

the whole process can be cancelled safely

the thread can be cancelled â€“ safely or otherwise doesnâ€™t matter

the thread can be cancelled safely

the whole process can be cancelled safely

Cancelling a thread asynchronously

frees all the resources properly

When a web page is loading, and the user presses a button on the browser to stop loading the page?

the thread loading the page continues with the loading

the thread loading the page does not stop but continues with another task

the thread loading the page is paused

the thread loading the page is cancelled

What is Thread cancellation?

the task of destroying the thread once its work is done

the task of removing a thread once its work is done

the task of terminating a thread before it has completed

If a process does not call exec after forking

all the threads should not be duplicated

the program specified in the parameter to exec will replace the entire process

all the threads should be duplicated

all the threads should not be duplicated

If exec is called immediately after forking

all the threads will be duplicated

the program specified in the parameter to exec will replace the entire process

all the threads will be duplicated

all the threads may be duplicated

If a thread invokes the exec system call

the exec is ignored as it is invoked by a thread

only the exec executes as a separate process

the program specified in the parameter to exec will replace the entire process

the exec is ignored as it is invoked by a thread

A fork system call will fail if

the limit on the minimum number of processes that can be under execution by a single user would be executed

the previously executed statement is also a fork call

the limit on the maximum number of processes in the system would be executed

the limit on the minimum number of processes that can be under execution by a single user would be executed

In the Many to Many model true concurrency cannot be gained because

other threads only from other processes are allowed to run

other threads are strictly prohibited from running

other threads are allowed to run

other threads only from other processes are allowed to run

When is the Many to One model at an advantage?

when the program has to be multi- threaded

when the program does not need multithreading

when the program has to be multi- threaded

when there is a single processor

Which of the following is the drawback of the One to One Model?

increased concurrency provided by this model

decreased concurrency provided by this model

creating so many threads at once can crash the system

creating a user thread requires creating the corresponding kernel thread

The One to One model allows

increased or decreased concurrency

concurrency equivalent to other models

In the Many to One model, multiple threads are unable to run in parallel on multiprocessors because of

many user threads have access to just one kernel thread

only one thread can access the kernel at a time

many user threads have access to just one kernel thread

there is only one kernel thread

In the Many to One model, if a thread makes a blocking system call

a part of the process will stay blocked, with the rest running

the entire process will be blocked

a part of the process will stay blocked, with the rest running

If a kernel thread performs a blocking system call,

the kernel cannot schedule another thread in the same application for execution

the kernel can schedule another thread in the application for execution

the kernel cannot schedule another thread in the same application for execution

the kernel must schedule another thread of a different application for execution

the kernel must schedule another thread of the same application on a different processor

Because the kernel thread management is done by the Operating System itself

kernel threads are easier to manage as well as create then user threads

kernel threads are faster to create than user threads

kernel threads are slower to create than user threads

kernel threads are easier to manage as well as create then user threads

A process having multiple threads of control implies

it can do only one task at a time, but much faster

it can do more than one task at a time

it can do only one task at a time, but much faster

it has to use only one thread per process

Multithreading on a multi â€“ CPU machine

can have multiple or a single thread for execution

has multiple threads of execution

has a single thread of execution

can have multiple or a single thread for execution

Resource sharing helps

share the memory and resources of the process to which the threads belong

an application have several different threads of activity all within the same address space

reduce the address space that a process could potentially use

A thread shares its resources(like data section, code section, open files, signals) with

other process similar to the one that the thread belongs to

other threads that belong to similar processes

other threads that belong to the same process

Thread synchronization is required because

all threads of a process share the same address space

all threads of a process share the same global variables

all threads of a process can share the same files

Termination of the process terminates

first two threads of the process

The jacketing technique is used to

convert a blocking system call into non blocking system call

557 + Mcqs in Operating System in Computer Science Engineering (CSE) Page 3 McqOptions

101.	Each connection arriving at multi threaded servers via network is generally
A.	is directly put into the blocking queue
B.	is wrapped as a task and passed on to a thread pool
C.	is kept in a normal queue and then sent to the blocking queue from where it is dequeued
D.	none of the mentioned
Answer» C. is kept in a normal queue and then sent to the blocking queue from where it is dequeued

Discussion

102.	Thread pools are useful when
A.	when we need to limit the number of threads running in the application at the same time
B.	when we need to limit the number of threads running in the application as a whole
C.	when we need to arrange the ordering of threads
D.	none of the mentioned
Answer» B. when we need to limit the number of threads running in the application as a whole

Discussion

103.	A process can never be sure that a signal it has sent
A.	has which identifier
B.	has not been lost
C.	has been sent
D.	all of the mentioned
Answer» C. has been sent

Discussion

104.	In most cases, if a process is sent a signal while it is executing a system call
A.	the system call will continue execution and the signal will be ignored completely
B.	the system call is interrupted by the signal, and the signal handler comes in
C.	the signal has no effect until the system call completes
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

105.	Instead of starting a new thread for every task to execute concurrently, the task can be passed to a
A.	process
B.	thread pool
C.	thread queue
D.	none of the mentioned
Answer» C. thread queue

Discussion

106.	In UNIX, the Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â system call is used to send a signal.
A.	sig
B.	send
C.	kill
D.	sigsend
Answer» D. sigsend

Discussion

107.	The usefulness of signals as a general inter process communication mechanism is limited because
A.	they do not work between processes
B.	they are user generated
C.	they cannot carry information directly
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

108.	The usual effect of abnormal termination of a program is
A.	core dump file generation
B.	system crash
C.	program switch
D.	signal destruction
Answer» B. system crash

Discussion

109.	In UNIX, the set of masked signals can be set or cleared using the Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â function.
A.	sigmask
B.	sigmaskproc
C.	sigprocmask
D.	sigproc
Answer» D. sigproc

Discussion

110.	The Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â maintains pending and blocked bit vectors in the context of each process.
A.	cpu
B.	memory
C.	process
D.	kernel
Answer» E.

Discussion

111.	When a process blocks the receipt of certain signals?
A.	the signals are delivered
B.	the signals are not delivered
C.	the signals are received until they are unblocked
D.	the signals are received by the process once they are delivered
Answer» B. the signals are not delivered

Discussion

112.	Signals of a given type
A.	are queued
B.	are all sent as one
C.	cannot be queued
D.	none of the mentioned
Answer» C. cannot be queued

Discussion

113.	Signals are identified by
A.	signal identifiers
B.	signal handlers
C.	signal actions
D.	none of the mentioned
Answer» B. signal handlers

Discussion

114.	Signals that occur at the same time, are presented to the process
A.	one at a time, in a particular order
B.	one at a time, in no particular order
C.	all at a time
D.	none of the mentioned
Answer» C. all at a time

Discussion

115.	The three ways in which a process responds to a signal are
A.	ignoring the signal
B.	handling the signal
C.	performing some default action
D.	all of the mentioned
Answer» E.

Discussion

116.	Which of the following is not TRUE?
A.	processes may send each other signals
B.	kernel may send signals internally
C.	a field is updated in the signal table when the signal is sent
D.	each signal is maintained by a single bit
Answer» D. each signal is maintained by a single bit

Discussion

117.	If multiple threads are concurrently searching through a database and one thread returns the result then the remaining threads must be
A.	continued
B.	cancelled
C.	protected
D.	none of the mentioned
Answer» C. protected

Discussion

118.	Cancellation point is the point where
A.	the thread can be cancelled â€“ safely or otherwise doesnâ€™t matter
B.	the thread can be cancelled safely
C.	the whole process can be cancelled safely
D.	none of the mentioned
Answer» C. the whole process can be cancelled safely

Discussion

119.	When the target thread periodically checks if it should terminate and terminates itself in an orderly manner, it is called?
A.	asynchronous cancellation
B.	systematic cancellation
C.	sudden termination
D.	deferred cancellation
Answer» E.

Discussion

120.	Cancelling a thread asynchronously
A.	frees all the resources properly
B.	may not free each resource
C.	spoils the process execution
D.	none of the mentioned
Answer» C. spoils the process execution

Discussion

121.	When one thread immediately terminates the target thread, it is called
A.	asynchronous cancellation
B.	systematic cancellation
C.	sudden termination
D.	deferred cancellation
Answer» B. systematic cancellation

Discussion

122.	When a web page is loading, and the user presses a button on the browser to stop loading the page?
A.	the thread loading the page continues with the loading
B.	the thread loading the page does not stop but continues with another task
C.	the thread loading the page is paused
D.	the thread loading the page is cancelled
Answer» E.

Discussion

123.	What is Thread cancellation?
A.	the task of destroying the thread once its work is done
B.	the task of removing a thread once its work is done
C.	the task of terminating a thread before it has completed
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

124.	If a process does not call exec after forking
A.	the program specified in the parameter to exec will replace the entire process
B.	all the threads should be duplicated
C.	all the threads should not be duplicated
D.	none of the mentioned
Answer» C. all the threads should not be duplicated

Discussion

125.	If exec is called immediately after forking
A.	the program specified in the parameter to exec will replace the entire process
B.	all the threads will be duplicated
C.	all the threads may be duplicated
D.	none of the mentioned
Answer» B. all the threads will be duplicated

Discussion

126.	If a thread invokes the exec system call
A.	only the exec executes as a separate process
B.	the program specified in the parameter to exec will replace the entire process
C.	the exec is ignored as it is invoked by a thread
D.	none of the mentioned
Answer» C. the exec is ignored as it is invoked by a thread

Discussion

127.	Which of the following system calls transforms executable binary file into a process?
A.	fork
B.	exec
C.	ioctl
D.	longjmp
Answer» C. ioctl

Discussion

128.	A fork system call will fail if
A.	the previously executed statement is also a fork call
B.	the limit on the maximum number of processes in the system would be executed
C.	the limit on the minimum number of processes that can be under execution by a single user would be executed
D.	all of the mentioned
Answer» C. the limit on the minimum number of processes that can be under execution by a single user would be executed

Discussion

129.	Which of the following system calls does not return control to the calling point, on termination?
A.	fork
B.	exec
C.	ioctl
D.	longjmp
Answer» C. ioctl

Discussion

130.	In the Many to Many model true concurrency cannot be gained because
A.	other threads are strictly prohibited from running
B.	other threads are allowed to run
C.	other threads only from other processes are allowed to run
D.	none of the mentioned
Answer» C. other threads only from other processes are allowed to run

Discussion

131.	When is the Many to One model at an advantage?
A.	when the program does not need multithreading
B.	when the program has to be multi- threaded
C.	when there is a single processor
D.	none of the mentioned
Answer» B. when the program has to be multi- threaded

Discussion

132.	Which of the following is the drawback of the One to One Model?
A.	increased concurrency provided by this model
B.	decreased concurrency provided by this model
C.	creating so many threads at once can crash the system
D.	creating a user thread requires creating the corresponding kernel thread
Answer» E.

Discussion

133.	The One to One model allows
A.	increased concurrency
B.	decreased concurrency
C.	increased or decreased concurrency
D.	concurrency equivalent to other models
Answer» B. decreased concurrency

Discussion

134.	In the Many to One model, multiple threads are unable to run in parallel on multiprocessors because of
A.	only one thread can access the kernel at a time
B.	many user threads have access to just one kernel thread
C.	there is only one kernel thread
D.	none of the mentioned
Answer» B. many user threads have access to just one kernel thread

Discussion

135.	In the Many to One model, if a thread makes a blocking system call
A.	the entire process will be blocked
B.	a part of the process will stay blocked, with the rest running
C.	the entire process will run
D.	none of the mentioned
Answer» B. a part of the process will stay blocked, with the rest running

Discussion

136.	The model in which one user-level thread is mapped to many kernel level threads is called
A.	many to one model
B.	one to many model
C.	many to many model
D.	one to one model
Answer» C. many to many model

Discussion

137.	If a kernel thread performs a blocking system call,
A.	the kernel can schedule another thread in the application for execution
B.	the kernel cannot schedule another thread in the same application for execution
C.	the kernel must schedule another thread of a different application for execution
D.	the kernel must schedule another thread of the same application on a different processor
Answer» B. the kernel cannot schedule another thread in the same application for execution

Discussion

138.	Because the kernel thread management is done by the Operating System itself
A.	kernel threads are faster to create than user threads
B.	kernel threads are slower to create than user threads
C.	kernel threads are easier to manage as well as create then user threads
D.	none of the mentioned
Answer» C. kernel threads are easier to manage as well as create then user threads

Discussion

139.	The kernel is Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â of user threads.
A.	a part of
B.	the creator of
C.	unaware of
D.	aware of
Answer» D. aware of

Discussion

140.	The model in which one kernel thread is mapped to many user-level threads is called
A.	many to one model
B.	one to many model
C.	many to many model
D.	one to one model
Answer» B. one to many model

Discussion

141.	A process having multiple threads of control implies
A.	it can do more than one task at a time
B.	it can do only one task at a time, but much faster
C.	it has to use only one thread per process
D.	none of the mentioned
Answer» B. it can do only one task at a time, but much faster

Discussion

142.	Multithreading on a multi â€“ CPU machine
A.	has multiple threads of execution
B.	has a single thread of execution
C.	can have multiple or a single thread for execution
D.	none of the mentioned
Answer» C. can have multiple or a single thread for execution

Discussion

143.	Resource sharing helps
A.	share the memory and resources of the process to which the threads belong
B.	an application have several different threads of activity all within the same address space
C.	reduce the address space that a process could potentially use
D.	all of the mentioned
Answer» E.

Discussion

144.	A thread shares its resources(like data section, code section, open files, signals) with
A.	other process similar to the one that the thread belongs to
B.	other threads that belong to similar processes
C.	other threads that belong to the same process
D.	all of the mentioned
Answer» D. all of the mentioned

Discussion

145.	A thread is also called
A.	light weight process(lwp)
B.	heavy weight process(hwp)
C.	process
D.	none of the mentioned
Answer» B. heavy weight process(hwp)

Discussion

146.	The register context and stacks of a thread are deallocated when the thread?
A.	terminates
B.	blocks
C.	unblocks
D.	spawns
Answer» B. blocks

Discussion

147.	Which one of the following is not a valid state of a thread?
A.	running
B.	parsing
C.	ready
D.	blocked
Answer» C. ready

Discussion

148.	Thread synchronization is required because
A.	all threads of a process share the same address space
B.	all threads of a process share the same global variables
C.	all threads of a process can share the same files
D.	all of the mentioned
Answer» E.

Discussion

149.	Termination of the process terminates
A.	first thread of the process
B.	first two threads of the process
C.	all threads within the process
D.	no thread within the process
Answer» D. no thread within the process

Discussion

150.	The jacketing technique is used to
A.	convert a blocking system call into non blocking system call
B.	create a new thread
C.	communicate between threads
D.	terminate a thread
Answer» B. create a new thread

Discussion

Explore topic-wise MCQs in Computer Science Engineering (CSE).

Each connection arriving at multi threaded servers via network is generally

Thread pools are useful when

A process can never be sure that a signal it has sent

In most cases, if a process is sent a signal while it is executing a system call

Instead of starting a new thread for every task to execute concurrently, the task can be passed to a

In UNIX, the Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â system call is used to send a signal.

The usefulness of signals as a general inter process communication mechanism is limited because

The usual effect of abnormal termination of a program is

In UNIX, the set of masked signals can be set or cleared using the Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â function.

The Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â maintains pending and blocked bit vectors in the context of each process.

When a process blocks the receipt of certain signals?

Signals of a given type

Signals are identified by

Signals that occur at the same time, are presented to the process

The three ways in which a process responds to a signal are

Which of the following is not TRUE?

If multiple threads are concurrently searching through a database and one thread returns the result then the remaining threads must be

Cancellation point is the point where

When the target thread periodically checks if it should terminate and terminates itself in an orderly manner, it is called?

Cancelling a thread asynchronously

When one thread immediately terminates the target thread, it is called

When a web page is loading, and the user presses a button on the browser to stop loading the page?

What is Thread cancellation?

If a process does not call exec after forking

If exec is called immediately after forking

If a thread invokes the exec system call

Which of the following system calls transforms executable binary file into a process?

A fork system call will fail if

Which of the following system calls does not return control to the calling point, on termination?

In the Many to Many model true concurrency cannot be gained because

When is the Many to One model at an advantage?

Which of the following is the drawback of the One to One Model?

The One to One model allows

In the Many to One model, multiple threads are unable to run in parallel on multiprocessors because of

In the Many to One model, if a thread makes a blocking system call

The model in which one user-level thread is mapped to many kernel level threads is called

If a kernel thread performs a blocking system call,

Because the kernel thread management is done by the Operating System itself

The kernel is Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â of user threads.

The model in which one kernel thread is mapped to many user-level threads is called

A process having multiple threads of control implies

Multithreading on a multi â€“ CPU machine

Resource sharing helps

A thread shares its resources(like data section, code section, open files, signals) with

A thread is also called

The register context and stacks of a thread are deallocated when the thread?

Which one of the following is not a valid state of a thread?

Thread synchronization is required because

Termination of the process terminates

The jacketing technique is used to