Operating Systems Concepts

Question 1

• Bits are not typically set by the programmer; it is false that they are set as a result of program operation.

Question 2

• A design change in the structure or semantics of the process control block could affect a number of modules in the OS.

Question 3

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

Question 4

• In a pure ULT facility, all thread management is done by the application, and the kernel is not aware of the existence of threads.

Question 5

• Batch processing and time-sharing use multiprogramming.

Question 6

• It is false that interrupts, signals, messages, and information in I/O buffers are all examples of reusable resources.

Question 7

• An OS should be constructed to permit effective development, testing, and introducing new system functions without interfering with service.

Question 8

• A process waiting for access to a critical section does consume consume processor time.

Question 9

• A file server is an example of an application that could make use of threads.

Question 10

• Cooperation by sharing covers processes that interact with other processes, explicitly aware of them.

Question 11

• The principle objective of Batch Multiprogramming is to minimize response time is false.

Question 12

• Deadlock avoidance is not more restrictive than deadlock prevention.

Question 13

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

Question 14

• The unit of dispatching is usually referred to as a task.

Question 15

• Atomicity guarantees isolation from concurrent processes.

Question 16

• A process not in main memory is not immediately available for execution, regardless of whether or not it is awaiting an event:

Question 17

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

Question 18

• The execution of a process is not carried out relative to the speed of other concurrent processes.

Question 19

• Windows is not an example of a user-level thread approach.

Question 20

• The strategy of deadlock avoidance is to design a system in such a way that the possibility of deadlock is excluded.

Question 21

• The process was placed in a suspended state by an agent; either itself, a parent process, or the OS, for the purpose of preventing its execution is characteristic of a suspended process.

Question 22

• A means for two processes to exchange information is with the use of messages

Question 23

• Deadlock detection is characterized by the presence of many single-threaded processes.

Question 24

• Kernel level threads (KLT) requires a mode switch to the kernel to switch thread to another within the same process.

Question 25

• The zombie state is when the thread terminated.

Question 26

• Once the processes have progressed into the fatal region, those processes will deadlock.

Question 27

• Nonblocking send, blocking receive allows a process to send one or more messages to a variety of destinations as quickly as possible.

Question 28

• A process in the blocked state when it is in main memory and awaiting an event.

Question 29

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

Question 30

• Reusable resources include processors, I/O channels, main and secondary memory, devices and data structures such as files, databases, and semaphores.

Question 31

• A total of 9 process states are recognized by the UNIX SVR4 operating system.

Question 32

• With mutual exclusion, 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.

Question 33

• A semaphore is an integer value used for signalling among processes.

Question 34

• A many-to-many relationship allows multiple server processes to provide concurrent service to multiple clients.

Question 35

• The term spin waiting 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.

Question 36

• Kernel threads are the fundamental entities that can be scheduled and dispatched to run on one of the system processors.

Question 37

• Solaris is a good example of an OS using a combined ULT/KLT approach.

Question 38

• The key states for a thread are: Running, ready, and Blocked.

Question 39

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

Question 40

• The process image is the collection of program, data, stack, and attributes defined in the process control block

Question 41

• Deadlock prevention strategies are very conservative and solve the problem of deadlock by limiting access to resources and by imposing restrictions on processes.

Question 42

• A critical section 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.

Question 43

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

Question 44

• Concurrency arises in three different contexts: multiple applications, structured applications, and operating system structure.

Question 45

• The strategy of resource allocation denial is referred to as the banker's algorithm

Question 46

• In the case of indirect addressing, 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.

Question 47

• The earliest computers employed multiprogramming processing, a name derived by the way the users have access to the systems

Question 48

• Multithreading is a technique in which a process, executing an application, is divided into threads that can run concurrently.

Question 49

• The basic form of communication between processes or threads in which process/threads are fully aware of the existence of each other in a microkernel operating system is by sending or receiving messages.

Question 50

• contains sufficient information so that it is possible to interrupt a running process and later resume execution as if the interruption had not occurred: process control block

Question 51

• Tables provide information about the existence of files, their location on secondary memory, their current status, and other attributes: file.

Question 52

• Deadlock avoidance allows the three necessary conditions but makes judicious choices to assure that the deadlock point is never reached

Question 53

• A reusable resource is one that can be safely used by only one process at a time and is not depleted by that use

Windows

• Windows makes use of two types of process-related objects: processes and threads

Question 54

• 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: resource allocation graph

Question 55

• The process control block information can be grouped into three general categories: process identification, processor state information and process control information.

Question 56

• For FCFS job scheduling, the average waiting time is 3.2.
• For SJF (Non-Preemptive) job scheduling, the average waiting time is 3.0.
• For the FCFS or SJF (Preemptive), the average burst Time is 3.0.
• For the FCFS, the average Total Time is 6.2
• For the SJF (Non-Preemptive), what is the average Total Time is 6.0.

Question 57

• Pr(R->R) after 2 Secs is 0.29
• Pr(E->Z) after 2 Secs is 0.51
• Pr(E->R) after 2 Secs is 0.20
• Pr(Z->Z) after 4 Secs is of 1.00
• Pr(Z->R) after 10 Secs is 0.00

Question 58

• In Line 2 of question 63, the value of '?' is is 1.0
• In Line 1 of question 63, value of '?' is 4. 1002

Question 59

• The requested system is in a safe state utilizing the bankers algorithm
• The content of the matrix 'Need'= MAX-Allocation at time T is 1. (0, 7, 5, 0), (1,0, 0, 2), (0, 0, 2, 0), and (0, 6, 4, 2).
• If a request from process P1 arrives for (0,4,2,0), can the request be granted immediately is by answering with 6. denied