Chapter 6 - OS2T

Question 1

Deadlock is permanent because none of the events is ever triggered.

Answer

true

Question 2

All deadlocks involve conflicting needs for resources by two or more processes.

Answer

true

Question 3

Interrupts, signals, messages, and information in IO buffers are all examples of reusable resources.

Answer

true

Question 4

A useful tool in characterizing the allocation of resources to processes is the resource allocation graph.

Answer

true

Question 5

For deadlock to occur, there must not only be a fatal region, but also a sequence of resource requests that has led into the fatal region.

Answer

true

Question 6

An indirect method of deadlock prevention is to prevent the occurrence of a circular wait

Answer

true

Question 7

If access to a resource requires mutual exclusion then mutual exclusion must be supported by the OS.

Answer

true

Question 8

The OS may preempt the second process and require it to release its resources if a process requests a resource that is currently held by another process.

Answer

true

Question 9

An unsafe state is one in which there is at least one sequence of resource allocations to process that does not result in a deadlock.

Answer

true

Question 10

An atomic operation executes without interruption and without interference.

Answer

true

Question 11

Deadlock avoidance is more restrictive than deadlock prevention

Answer

true

Question 12

The dining philosophers problem can be representative of problems dealing with the coordination of shared resources which may occur when an application includes concurrent threads of execution.

Answer

true

Question 13

A signal is similar to a hardware interrupt but does not employ priorities

Answer

true

Question 14

Deadlock avoidance requires knowledge of future process resource requests.

Answer

true

Question 15

A mutex is used to ensure that only one thread at a time can access the resource protected by the mutex

Answer

true

Question 16

A set of processes is [blank_start]_________[blank_end] when each process in the set is blocked awaiting an event that can only be triggered by another blocked process in the set.

Accepted Answer

deadlocked

Question 17

Examples of [blank_start]__________[blank_end] include processors, I/O channels, main and secondary memory, devices, and data structures such as files, databases, and semaphores.

Accepted Answer

reusable resources

Question 18

With _________ only one process may use a resource at a time and no process may access a resource unit that has been allocated to another process.

Accepted Answer

mutual exclusion

Answer

circular wait

Answer

hold and wait

Answer

non-pre-emption

Question 19

A closed chain of processes exists, such that each process holds at least one resource needed by the next process in the chain is the condition of [blank_start]__________[blank_end] .

Accepted Answer

circular wait

Question 20

Once the processes have progressed into the [blank_start]__________[blank_end] , those processes will deadlock.

Accepted Answer

fatal region

Question 21

The strategy of deadlock [blank_start]_________[blank_end] is to design a system in such a way that the possibility of deadlock is excluded.

Accepted Answer

prevention

Question 22

The [blank_start]_________[blank_end] condition can be prevented by requiring that a process request all of its required resources at one time and blocking the process until all requests can be granted simultaneously.

Accepted Answer

hold and wait

Question 23

The fastest form of interprocess communication provided in UNIX is [blank_start]__________[blank_end] .

Accepted Answer

shared memory

Question 24

The [blank_start]__________[blank_end] condition can be prevented by defining a linear ordering of resource types.

Accepted Answer

circular wait

Question 25

Requested resources are granted to processes whenever possible with [blank_start]_________[blank_end] .

Accepted Answer

deadlock detection

Question 26

One of the most significant contributions of UNIX to the development of operating systems is the [blank_start]_________[blank_end] .

Accepted Answer

pipe

Question 27

A [blank_start]__________[blank_end] is a software mechanism that informs a process of the occurrence of asynchronous events.

Accepted Answer

signal

Question 28

The most common technique used for protecting a critical section in Linux is the [blank_start]__________[blank_end].

Accepted Answer

spinlock

Question 29

The [blank_start]_________[blank_end] allows multiple threads to have simultaneous read-only access to an object protected by the lock.

Accepted Answer

readers/writer lock

Question 30

The [blank_start]_________[blank_end] is useful in sending a signal to a thread indicating that a particular event has occurred.

Accepted Answer

event object

Question 31

[blank_start]_________[blank_end] can be defined as the permanent blocking of a set of processes that either compete for system resources or communicate with each other.

Accepted Answer

Deadlock

Question 32

A [blank_start]_________[blank_end] resource is one that can be safely used by only one process at a time and is not depleted by that use.

Accepted Answer

reusable

Question 33

A [blank_start]_________[blank_end] resource is one that can be created and destroyed.

Accepted Answer

consumable

Question 34

The [blank_start]_________[blank_end] is a directed graph that depicts a state of the system of resources and processes, with each process and each resource represented by a node.

Accepted Answer

resource allocation graph

Question 35

Three conditions of policy must be present for a deadlock to be possible: mutual exclusion, no preemption, and [blank_start]_________[blank_end] .

Accepted Answer

hold and wait

Question 36

Three general approaches exist for dealing with deadlock: prevent, avoid, and [blank_start]__________[blank_end] .

Accepted Answer

detect

Question 37

[blank_start]__________[blank_end] allows the three necessary conditions but makes judicious choices to assure
that the deadlock point is never reached.

Accepted Answer

deadlock avoidance

Question 38

The strategy of resource allocation denial is referred to as the [blank_start]___________[blank_end] .

Accepted Answer

bankers algorithm

Question 39

The [blank_start]_________[blank_end] of the system reflects the current allocation of resources to processes.

Accepted Answer

state

Question 40

[blank_start]_________[blank_end] strategies are very conservative and solve the problem of deadlock by limiting access to resources and by imposing restrictions on processes.

Accepted Answer

deadlock prevention

Question 41

Inspired by the concept of co-routines, a [blank_start]_________[blank_end] is a circular buffer allowing two processes to communicate on the producer-consumer model.

Accepted Answer

pipe

Question 42

Two types of atomic operations are defined in Linux: integer operations and [blank_start]_______[blank_end].

Accepted Answer

bitmap operations

Question 43

Linux provides three types of semaphore facilities in the kernel: binary semaphores, counting semaphores, and [blank_start]__________[blank_end] .

Accepted Answer

reader-writer semaphores

Question 44

An executable entity within a process is a [blank_start]__________[blank_end] object.

Accepted Answer

thread

Question 45

A program invocation, including the address space and resources required to run the program is a [blank_start]__________[blank_end] object.

Accepted Answer

process

Chapter 6 - OS2T

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