Chap 5

Question 1

The central themes of operating system design are all concerned with the management of processes and threads.

Answer 1

TRUE

Question 2

It is possible in a single-processor system to not only interleave the execution of multiple processes but also overlap them

Answer 2

FALSE

Question 3

As an extension of the principles of modular design and structured programming, some applications can be effectively programmed as a set of concurrent processes.

Answer 3

TRUE

Question 4

Race condition is a situation in which two or more processes continuously change their states in response to changes in the other process(es) without doing any useful work.

Answer 4

FALSE

Question 5

The sharing of main memory among processes is useful to permit efficient and close interaction among processes because such sharing does not leads to many problems.

Answer 5

FALSE

Question 6

When processes cooperate by communication, the various processes participate in a common effort that links all of the processes.

Answer 6

TRUE

Question 7

Atomicity guarantees isolation from concurrent processes.

Answer 7

TRUE

Question 8

Concurrent processes do not come into conflict with each other when they are competing for the use of the same resource.

Answer 8

FALSE

Question 9

Two or more processes can cooperate by means of simple signals, such that a process can be forced to stop at a specified place until it has received a specific signal.

Answer 9

TRUE

Question 10

The functioning of a process, and the output it produces, must be independent of the speed at which its execution is carried out relative to the speed of other concurrent processes.

Answer 10

TRUE

Question 11

A process that is waiting for access to a critical section does not consume processor time.

Answer 11

FALSE

Question 12

The case of cooperation by sharing covers processes that interact with other processes without being explicitly aware of them.

Answer 12

TRUE

Question 13

It is possible for one process to lock the mutex and for another process to unlock it.

Answer 13

FALSE

Question 14

On of the most common problems faced in concurrent processing is the producer/consumer problem.

Answer 14

TRUE

Question 15

Processes need to be synchronized to enforce mutual exclusion.

Answer 15

TRUE

Question 16

The management of multiple processes within a uniprocessor system is ___________.

Answer 16

multiprogramming

Question 17

A situation in which a runnable process is overlooked indefinitely by the scheduler, although it is able to proceed, is ____________.

Answer 17

starvation

Question 18

The requirement that when one process is in a critical section that access shared resources, no other process may be in a critical section that accesses any of those shared resources is ____________.

Answer 18

mutual exclusion

Question 19

A means for two processes to exchange information is with the use of ____________.

Answer 19

messages

Question 20

A semaphore that does not specify the order in which processes are removed from the queue is a _________ semaphore.

Answer 20

weak

Question 21

A ____________ occurs when multiple processes or threads read and write data items so that the final result depends on the order of execution of instructions in the multiple processes.

Answer 21

race condition

Question 22

A ___________ is an integer value used for signaling among processes.

Answer 22

semaphore

Question 23

__________ is when the sequence of instruction is guaranteed to execute as a group, or not execute at all, having no visible effect on system state.

Answer 23

atomic operation

Question 24

___________ are memory words used as a synchronization mechanism.

Answer 24

event flags

Question 25

The term _________ refers to a technique in which a process can do nothing until it gets permission to enter its critical section but continues to execute an instruction or set of instructions that tests the appropriate variable to gain entrance.

Answer 25

spin waiting

Question 26

A _______ is a data type that is used to block a process or thread until a particular condition is true.

Answer 26

condition variable

Question 27

A semaphore whose definition includes the policy that the process that has been blocked the longest is released from the queue first is called a __________ semaphore.

Answer 27

strong

Question 28

The __________ is a programming language construct that provides equivalent functionality to that of semaphores and is easier to control.

Answer 28

monitor

Question 29

Probably the most useful combination, ________ allows a process to send one or more messages to a variety of destinations as quickly as possible.

Answer 29

nonblocking send, blocking receive

Question 30

A ___________ relationship allows multiple server processes to provide concurrent service to multiple clients.

Answer 30

many-to-many

Question 31

____________ arises in three different contexts: multiple applications, structured application, and operating system structure.

Answer 31

concurrency

Question 32

_________ was invented to allow processing time to be dynamically shared among a number of active applications.

Answer 32

multiprogramming

Question 33

A situation in which two or more processes are unable to proceed because each is waiting for one of the others to do something is a ____________.

Answer 33

deadlock

Question 34

In the case of competing processes three control problems must be faced: mutual exclusion, deadlock, and _________.

Answer 34

starvation

Question 35

A ______________ is a semaphore that takes only the values of 0 and 1.

Answer 35

binary semaphore

Question 36

A situation in which multiple threads or processes read and write a shared data item and the final result depends on the relative timing of their execution is a ___________ .

Answer 36

race condition

Question 37

__________ is a function or action implemented as a sequence of one or more instructions that appears to be indivisible; no other process can see an intermediate state or interrupt the operations.

Answer 37

atomic operation

Question 38

A ___________ is a programming language construct that encapsulates variables, access procedures, and initialization code within an abstract data type.

Answer 38

monitor

Question 39

__________ is a section of code within a process that requires access to shared resources and that must not be executed while another process is in a corresponding section of code.

Answer 39

critical section

Question 40

In the case of _________, processes are sharing resources without being aware of the other processes.

Answer 40

competition

Question 41

A __________ is a mutual exclusion mechanism in which a process executes in an infinite loop waiting for the value of a lock variable to indicate availability

Answer 41

spinlock

Question 42

Only three operations may be performed on a semaphore: initialize, increment, and __________.

Answer 42

decrement

Question 43

A monitor supports synchronization by the use of _________ that are contained within the monitor and accessible only within the monitor.

Answer 43

condition variables

Question 44

In the case of _______, messages are not sent directly from sender to receiver but rather are sent to a shared data structure consisting of queues that can temporarily hold messages.

Answer 44

indirect addressing

Question 45

The classic concurrency problem that involves multiple readers that can read from a shared data area when no single writer is exclusively writing to it is the ___________ Problem.

Answer 45

readers/writers