Utilities are:
Processor registers
Application programs
Opcodes
System programs
The process index register
Contains the index into the process list of process currently controlling the processor.
Contains the staring address of the region of memory occupied by the process.
Define the region in memory occupied by the process
Points to the next isntruction in that process to be executed
The end user views a computer system in terms of:
A set of machine instructions
A set of applications
A set of system programs
Utilities
Choose the storage management responsibility for «The OS can achieve efficiency by assigning memory to jobs only as needed:
Process isolation
Protection and access control
Automatic allocation and management
Long-term storage
Support of modular programming
"The OS as a User/Computer Interface" corresponds to the following objective:
Efficiency
Convenience
Ability to evolve
_____ is generally faster than _____
first fit, best fit
none of the above
best fit, first fit
worst fit, best fit
Memory partitioning algorithm that uses binary tree as a data structure is called:
First-fit algorithm
Buddy system
Next-fit algorithm
Best-fit algorithm
The address of a page table in memory is pointed by:
stack pointer
page table base register
program counter
page register
Which of the following is not true about the memory management?
segmented memory can be paged
virtual memory is used only in multi-user systems
segmentation suffers from external fragmentation
paging suffers from internal fragmentation
Main memory is broken into fixed-size blocks called
None of the above
Segments
Frames
Pages
In operating system each process has its own:
address space and global variables
set of data
program code
all of mentioned
Mutual exclusion can be provided by the:
both
mutex locks
binary semaphores
What is a medium-term scheduler?
It selects which process has to be executed next and allocates CPU
It selects which process has to be brought into the ready queue
It selects which process to remove from memory by swapping
The state of a process is defined by:
The activity to next to be executed by the process
The activity just executed by the process
The current activity of the process
The final activity of the process
What is a ready state of a process?
when process is using the CPU
when process is scheduled to run after some execution
when process is unable to run unitl some task has been completed
Which one of the following is the deadlock avoidance algorithm?
round-robin algorithm
elevator algorithm
banker's algorithm
dinning philosophers problem
A state is safe if:
the system can allocate resources to each process in some order and still avoid a deadlock
all of the above
the state keeps the system protected and safe
the system does not crash due to deadlock occurrence
The initial value of the semaphore, that allows only one of the many processes to enter their critical sections, is:
2
1
0
10
The segment of code in which the process may change common variables, update tables, write into files is known as:
critical section
mutual exclusion
non-critical section
program
A problem encountered in multitasking when a process is perpetually denied necessary resources is called
starvation
aging
inversion
deadlock
A system is in the safe state if:
there exist a safe sequence
both A and B
What is the reusable resource?
that can be used by one process at a time and is not depleted by that use
that can be used by more than one process at a time
that can be shared between various threads
This illustrates the progress of two processes competing for two resources
joint progress diagram
joint ingres diagram.
joint regress diagram.
joint process diagram.
Current allocation of resources to processes where there is at least one sequence that does not result in deadlock is called
Safe state
Ambiguous state
Unsafe state
Alternative state
The resource vector defines:
total amount of each resource in the system
total amount of each resource NOT allocated to any process
total amount of resources required for all processes
total amount of each resource allocated to all processes
"No preemption" condition for deadlock is defined as
No resource can be forcibly removed from process holding it.
Process holds a resources while awaiting for other resource
Only one process may use a resource at a time
Each process holds resource needed by next process in chain
This matrix defines the current allocation to process i of resource j:
Claim matrix
Allocation matrix
Resource matrix
Request matrix
Which of the following cannot be interrupted?
Process
Thread
Atomic operation
Module
A minimum of ____ variables is/are required to be shared between processes to solve critical section problem.
three
two
one
four
For non-sharable resources like a printer, mutual exclusion:
must exist
may exist
must not exist
A monitor is type of:
high-level synchronization construct
low-level synchronization construct
An un-interruptible unit is known as:
atomic.
single
static
Part of program, where the shared memory is accessed and which should be executed invisibly, is called:
semaphores
directory
Current allocation of resources to processes where there is no sequence that does not result in deadlock is called:
Which of the following is not one of the principles of dealing with deadlock?
Initialization
Detection
Prevention
Avoidance
Deadlock inevitable region can be referred to as a:
fatal region
false region
final region
fun region
When each process in the set is blocked awaiting for resource seized by another blocked process:
it is deadlock
it is deadend
it is a softlock
It is a mortallock
What is NOT an example of reusable resource?
I/O channels
Semaphores
Processors
Interrupt
In the non-blocking send, blocking receive:
the sending process sends the message and resumes operation
the sending process keeps sending until it receives a message
sender continues on, receiver is blocked until the requested message arrives
The degree of multi-programming is:
the number of process in memory
the number of processes executed per unit time
the number of process in the ready queue
the number of process in the I/O queue
What controls the process in a single-threaded process model?
Process control block
Kernel stack control block
User address space control block
User stack control block
The context of a process in the PCB of a process DOESN'T contain:
memory-management information
context switch time
the process state
the value of CPU registers
Job control language was used to:
provide instructions to the monitor to improve job setup time.
control the sequence of events as the resident monitor
translate the user's program into object code
execute instructions
The hardware and software used in providing applications to a user can be viewed in a:
sandwich fashion
classified fashion
layered fashion
leveled fashion
Semaphore is a/an _____ to solve critical section problem.
integer variable
special program for a system
complex structure
hardware for a system
A situation where several processes access and manipulate the same data concurrently and the outcome of the execution depends on the particular order in which access takes place is called
data consistency
race condition
«The OS as a resource manager» corresponds to the following objective:
Choose the storage management responsibility for «Programmers should be able to define program modules and to create, destroy and after the size of modules dynamically»:
long-term storage
automatic allocation and management
support of modular programming
process isolation
The first fit, best fit and worst fit are strategies to select a:
free hole from a set of available holes.
processor to run the next process
process from a queue to put in memory
For every process there is a:
page table.
copy of page table
frame table
pointer to page table
The memory allocation scheme subject to "internal" fragmentation is
fixed partitioning.
virtual memory segmentation
pure demand paging
segmentation
In memory systems, boundary registers
are used for temporary program variable storage
are only necessary with fixed partitions
are only necessary with unequal-length partitions
track the beginning and ending of programs
Any program, no matter how small, will occupy an entire partition results in
paging
internal fragmentation
external fragmentation
The Process Control Block is:
a secondary storage section
process type variable
data structure
a block in memory
Which one of the following is synchronization tool?
socket
thread
pipe
semaphore
The link between two processes P and Q to send and receive messages is called:
communication link
message-passing link
synchronization tool
This system handles multiple interactive jobs:
Serial procesing
Simple batch system
Time-sharing system
Multiprogrammed batch system
"Two or more programs hung up waiting for each other". This error is caused by
Improper synchronization
Nondeterminate program operation
Deadlocks
Failed mutual exclusion
"Lost signals, duplicate signals received". This error is caused by:
improper synchronization
nondeterminate program operation
failed mutual exclusion
deadlocks
The principal tool available to system programmers in developing the early multiprogramming and multiuser interactive systems
Job Control Language
Ad hoc Method
Monitor
Fixed-length block of data in secondary memory is called:
frames
segments
pages
When the free memory is split into many unconnected pieces we call it:
Compaction
External fragmentation
Memory distribution
Internal fragmentation
If a page number is not found in the TLB, then it is known as a:
TLB miss
page fault
buffer miss
TLB hit
With paging there is no ______ fragmentation.
either type of
internal
external
If a page table entry is not in a main memory, then it is known as a:
This matrix defines the amount of resources of type j requested by process i:
«Hold and wait» condition for deadlock is defined as:
process holds a resource while awaiting for other resource.
no resource can be forcibly removed from process holding it
only one process may use a resource at a time
each process holds resource needed by next process in chain
«Circular wait» condition for deadlock is defined as:
each process holds a resource needed by next process in chain.
process holds a resource while awaiting for other resource
Four necessary conditions for deadlock to exist are: mutual exclusion, no-preemption, circular wait and _____
hold and wait
deadlock avoidance
race around condition
buffer overflow
This resource can safely be used by only one process at a time and is not depleted by that use:
refreshing resource
replenishing resource
refurbished resource
reusable resource
The available vector defines:
"No preemption" condition for deadlock is defined as:
Process holds a resource while awaiting for other resource
For sharable resources, mutual exclusion
is not required
is required
may be or may not be required
none of the mentioned
In the blocking send, blocking receive:
both sender and receiver are blocked until message is delivered
the sending process sends the message while receiver is blocked
In the non-blocking send, non-blocking receive:
sender continues on, receiver is blocked until the requested message arrives.
neither of processes are required to wait
the sending process keeps sending until the message is received
"More than one attempts to make use of a shared resource at the same time". This error is caused by:
Which of the following state transitions is not possible?
Blocked to running
Blocked to ready
Running to blocked
Ready to running
What is a short-term scheduler?
None of these
What is a long-term scheduler?
What is inter-process communication?
Communication between two threads of same process.
Communication between two process
Communication within the process
None of the mentioned
There were no OS with
Serial processing
Simple batch systems
Time sharing systems
Multiprogrammed batch systems
Inter-process communication
allows processes to communicate and synchronize their actions without using the same address space
allows the processes to only synchronize their actions without communication
allows processes to communicate and synchronize their actions when using the same address space
A sequence of instructions in a computer language to get the desired result is known as:
algorithm
process
instruction
In contiguous memory allocation
each process is contained in a single contiguous section of memory
the memory space is contiguous
all processes is contained in a single contiguous section of memory
A system clock generates an interrupts at a rate of approximately every 0.2 seconds. At each clock interrupt regained control and could assign processor to another user. Technique is known as:
Time scheduling
Time slicing
Time sliding
Time allocating
In internal fragmentation, memory is internal to a partition and
is not being used
is always used
is being used
The operating system maintains a ____ table that keeps track of how many frames have been allocated, how many are there and how many are available
memory
page
frame
segment
The algorithm is slow and may even tend to fill up memory with useless holes
Best fit
Worst fit
First fit
24. Which of the following statements is false?
I\O transfers are more efficient with large pages
a large page size causes instructions and data that will not be referenced brought into primary storage
a small page size causes large page tables
internal fragmentation is increased with small pages
Short-term scheduler, or dispatcher, picks a process. Each process in the queue is given some time in turn. The strategy is called
Round-robin technique
Prioritizing
Carousel technique
Merry-go-round technique
The limit register:
Defines the size of the region of (in bytes or words)
Contains the index into the process list of the process currently controlling the processor
Points to the next instruction in that process to be executed
Contains the staring address of the region of memory occupied by the process
Dispatcher is:
Small program which switches the processor from one process to another
Trace scheduler
Interrupt handler
User account manager
Process spawning is:
Creation of parent process
Creation of child process
Termination of parent process
Termination of child process
The code that changes the value of the semaphore is:
remainder section code
non – critical section code
critical section code
This resource can be created and destroyed
consumable resource
finite resource
restartable resource
resumable resource
What is NOT an example of consumable resource?
Information in I/O buffers.
Signals
Main memory
Messages
A binary semaphore is a semaphore with integer values (multiple choices):
—1
0.5
If more than one user or program attempts to make use of a shared resource at the same time, it may cause the error of
Mutual exclusion means that
if a process is executing in its critical section, then no other process must be executing in their critical sections
if a process is executing in its critical section, then all the resources of the system must be blocked until it finishes exclusion
if a process is executing in its critical section, then other processes must be executing in their critical section
The two kinds of semaphores are:
mutex
counting
binary
decimal
The objective of multi-programming is to:
have multiple programs waiting in a queue ready to run
to maximize CPU utilization
to minimize CPU utilization
A relationship between processes such that each has some part (critical section) which must not be executed while the critical section or another
Mutual exclusion
Multiprogramming
Semaphore
Multitasking
What is a method of memory allocation by which the program is subdivided into equal portions, or pages and core is subdivided into equal portions or blocks? It is a method of allocating processor time?
Paging
Virtual memory
Partition
Segmentation