Final Exam Multiple Choice Questions

A race condition___. A) results when several threads try to access and modify the same data concurrently B) will result only if the outcome of execution does not depend on the order in which instructions are executed C) results when several threads try to access the same data concurrently D) none of the above

A) results when several threads try to access and modify the same data concurrently

The tracks on a magnetic disk surface are divided into smaller regions called ___. A) sectors B) arms C) tracks D) cylinders E) heads

A) sectors

What are the two largest components of positioning time for a disk? A) seek time + rotational latency B) transfer time + transfer rate C) effective transfer rate - transfer rate D) cylinder positioning time + disk arm positioning time E) none of the above

A) seek time + rotational latency

The default scheduling class for a process in Solaris is ____. A) time sharing B) system C) interactive D) real-time

A) time sharing

To the SYSGEN program of an operating system, the least useful piece of information is____. A) what applications to install B) the CPU being used C) the amount of memory available D) Operating-system operations such as buffer sizes or CPU scheduling algorithms

A) what applications to install.

The ____ occurs in first-come-first-served scheduling when a process with a long CPU burst occupies the CPU. A) dispatch latency paradox B) convoy effect C) system-contention scope problem D) context switch overhead

B) Convoy effect

A(n) ____ refers to where a process is accessing/updating shared data. A) Entry section B) Critical section C) adaptive mutex D) test-and-set

B) Critical section

____ scheduling is approximated by predicting the next CPU burst with an exponential average of the measured lengths of previous CPU bursts. A) Multilevel queue B) SJF C) RR D) FCFS

B) SJF

A surreptitious access mechanism left behind by the creator of a program/system is called ___. A) a backdoor B) a trap door C) a trojan horse D) a worm

B) a trap door

A ____ is an example of a systems program. A) web browser B) command interpreter C) text formatter D) database system

B) command interpreter

In Linux and other UNIX-based operating systems, which of the following isn't considered a classification of users with respect to each file? A) owner B) current user C) group D) universe

B) current user

A ___ is a public key digitally signed by a trusted party. A) key ring B) digital certificate C) message digest D) digital key

B) digital certificate

A deadlocked state occurs whenever___. A) a process is waiting for I/O to a device that does not exist B) every process in a set is waiting for an event that can only be caused by another process in the set C) the system has no available free resources D) a process is unable to release its request for a resource after use

B) every process in a set is waiting for an event that can only be caused by another process in the set

A contiguous chunk of disk blocks is known as a(n) ___. A) disk block group B) extent C) inode D) file allocation table (FAT)

B) extent

A(n) ___ page table has one-page entry for each page frame of physical memory. A) clustered B) inverted C) forward-mapped D) multi-level

B) inverted

A semaphore ___. A) cannot be used to control access to a thread's critical sections B) is accessed through two standard operations C) can be modified simultaneously by multiple threads D) is essentially a real-number variable

B) is accessed through two standard operations

Optimal page replacement ____. A) is the page-replacement algorithm most often implemented in real systems B) is used mostly for comparison with other page-replacement schemes C) can suffer from Belady's anomaly D) requires that the system keep track of previously used pages.

B) is used mostly for comparison with other page-replacement schemes

Another necessary condition for deadlock is ___, which states that at least one resource must be in a non-sharable mode. A) hold and wait B) mutual exclusion C) circular wait D) no preemption

B) mutual exclusion

The ____ multithreading model maps a number of user-level threads to an equal number of kernel threads. A) many-to-one B) one-to-one C) many-to-some D) many-to-many

B) one-to-one

LWP is ____. A) short for "lightweight procedure" B) placed between user and kernel threads C) placed between system and kernel threads D) common in systems implementing one-to-one multithreading models

B) placed between user and kernel threads

The SSTF scheduling algorithm ___. A) services the request with the maximum seek time B) services the request with the minimum seek time C) services the next request in the current direction of head travel D) none of the above

B) services the request with the minimum seek time

In a paired-password system, ____. A) the user specifies two passwords B) the computer supplies one part of a password and the user enters the other part. C) passwords must contain equal amounts of numbers and digits paired together D) two users must enter their own separate password to gain access to the system.

B) the computer supplies one part of a password and the user enters the other part

Consider a system with a page size of 8 KB. How many bits must be used to represent the offset within a page. A) 10 B) 8 C) 13 D) 12

C) 13

How many philosophers may eat simultaneously in the Dining Philosophers problem with 7 philosophers? A) 1 B) 2 C) 3 D) 4 E) 5 F) all 7

C) 3

Which of the following would lead you to believe that a given system is an SMP-type system? A) There is a master-slave relationship between the processors. B) Each processor is assigned a specific task. C) Each processor can perform all tasks within the operating system. D) None of the above.

C) Each processor can perform all tasks within the operating system.

Which of the following scheduling algorithms is never preemptive? A) SJF B) RR C) FCFS D) priority scheduling

C) FCFS

___ is a symmetric stream encryption algorithm A) DES B) AES C) RC4 D) RSA E) SSL

C) RC4

In a system resource-allocation graph, ____. A) a directed edge from a process to a resource is called an assignment edge B) a directed edge from a resource to a process is called request edge C) a directed edge from a process to a resource is called a request edge D) none of the above

C) a directed edge from a process to a resource is called a request edge

A denial of service attack is ___. A) aimed at gaining information B) aimed at stealing resources C) aimed at disrupting legitimate use of a system D) generally not network-based

C) aimed at disrupting legitimate use of a system

A _____ saves the state of the currently running process and restores the state of the next process to run. A) save and restore B) state switch C) context switch D) none of these

C) context switch

In an access matrix, the ___ right allows a process to change the entries in a row. A) owner B) copy C) control D) switch

C) control

____ allows the parent and child processes to initially share the same pages, but when either process modifies a page, a copy of the shared page is created. A) memory mapping B) zero-fill-on-demand C) copy-on-write D) virtual memory fork

C) copy-on-write

A spinlock ___. A) is only advantageous on uniprocessor systems B) will ultimately result in a context switch when a process must wait on a lock. C) does not require a context switch when a process must wait on a lock D) is useful when locks are expected to be held for long amounts of time.

C) does not require a context switch when a process must wait on a lock.

Belady's anomaly is the observation that ___. A) giving more memory to a process will improve its performance B) as the number of allocated frames increases, the page-fault rate may decrease for all page replacement algorithms (PRAs) C) for some PRAs, the page-fault rate may increase as the number of allocated frames increases D) for some PRAs, the page-fault rate may decrease as the number of allocated frames increases

C) for some PRAs, the page-fault rate may increase as the number of allocated frames increases

The file allocation table (FAT) scheme used in MS-DOS and supported by Windows is a modified version of ___. A) contiguous allocation B) indexed allocation C) linked allocation D) multilevel indexed allocation

C) linked allocation

The surface of an individual magnetic disk platter is divided into circular regions called ___. A) sectors B) arms C) tracks D) cylinders E) heads

C) tracks

___ is the dynamic storage-allocation algorithm which results in the largest leftover hole in memory. A) first fit B) best fit C) worst fit D) none of these

C) worst fit

Which of the following is a benefit of allowing a program that is only partially in memory to execute? A) Programs can be written to use more memory than is available in physical memory. B) CPU utilization and throughput is increased. C) Less I/O is needed to load or swap each user program into memory. D) All of the above

D) All of the above

A Java thread may release a lock under which of the following circumstances? A) It exits a synchronized method B) It invokes the notify() method C) It invokes the wait() method. D) Both (A) and (C)

D) Both (A) and (C)

___ is an asymmetric block encryption algorithm. A) DES B) AES C) RC4 D) RSA E) SSL

D) RSA

Embedded computers typically run a _____ operating system. A) Windows B) Network C) Clustered D) Real-Time

D) Real-Time

_____ provide(s) an interface to the services provided by an operating system. A) Communication B) Simulators C) Shared memory D) System calls

D) System Calls

A code segment that misuses its environment is called ____. A) a backdoor B) a trap door C) a worm D) a trojan horse

D) a trojan horse

Which of the following would be an acceptable signal handling scheme for a multithreaded program? A) deliver the signal to the thread to which the signal applies B) deliver the signal to every thread in the process. C) delivers the signal to only certain threads in the process. D) all of the above

D) all of the above

Worms ____. A) use the spawn mechanism to ravage system performance B) can shut down an entire network C) continue to strike as the Internet expands D) all of the above

D) all of the above

A volume control bock ___. A) can contain information needed by the system to boot an operating system from that partition B) is a directory structure used to organize the files C) contains many of the file's details, including file permissions, ownership, size, and location of the data blocks D) contains information such as the number of blocks in a partition, size of the blocks, and free-block and FCB count and pointers.

D) contains information such as the number of blocks in a partition, size of the blocks, and free-blocks and FCB count and pointers.

Which of the following allocation methods ensures that only one access is needed to retrieve data from block belonging to a file on disk when performing direct access? A) linked allocation B) indexed allocation C) hashed allocation D) contiguous allocation

D) contiguous allocation

A(n) ___ is used in many file systems at the end of a file name to indicate the type of the file. A) magic number B) creator name C) hint D) extension E) none of these

D) extension

The Windows CreateProcess() system call creates a new process. What is the equivalent system call in UNIX? A) exec() B) UxCreateProcess() C) process() D) fork()

D) fork()

A process control block ____. A) stores the address of the next instruction to be processed by a different process B) determines which process is to be executed next C) is an example of a process queue D) includes information on the process's state

D) includes information on the process's state

The mapping of a logical address to a physical address is done in hardware by the ___. A) address generation chip B) relocation register C) physical address translation device D) memory-management unit

D) memory-management unit

One necessary condition for deadlock is ____, which states that a resource can be released only voluntarily by the process holding the resource A) hold and wait B) mutual exclusion C) circular wait D) no preemption

D) no preemption

A(n) ___ is a buffer that holds output for a device that cannot accept interleaved data streams. A) escape B) block device C) cache D) spool

D) spool

A ___ virus attempts to avoid detection by modifying parts of the system that could be used to detect it. A) polymorphic B) tunneling C) multipartite D) stealth

D) stealth

A mount point is ___. A) the root of the overall file system B) a location within a shared file system C) only appropriate for shared file systems D) the location within the file structure where the given files system is to be attached.

D) the location within the file structure where a given files system is to be attached.

A ____ uses an existing thread - rather than creating a new one - to complete a task. A) lightweight process B) remote procedure call C) scheduler activation D) thread pool

D) thread pool

Assume a system uses base and limit registers to control access to memory and their current values are 1000 and 850, respectively. Which of the following addresses is legal for the program to access? A) 1200 B) 999 C) 2800 D) all of these E) none of these

A) 1200

_____ is/are not a technique for passing parameters from an application to a system call. A) Cache Memory B) Registers C) Stack D) Special block in memory

A) Cache Memory

Which of the following disk head scheduling algorithms does not take into account the current position of the disk head? A) FCFS B) SSTF C) SCAN D) LOOK

A) FCFS

___ occurs when a process spends more time paging than executing. A) Thrashing B) Memory-mapping C) Swapping D) Demand paging

A) Thrashing

Which of the following is true of the Java programming language in relation to protection? A) When a class is loaded, the JVM assigns the class to a protection domain that gives the permissions of that class. B) It does not support the dynamic loading of untrusted classes over a network. C) It does not support the execution of mutually distrusting classes within the same JVM. D) Methods in the calling sequence are not responsible for requests to access a protected resource.

A) When a class is loaded, the JVM assigns the class to a protection domain that gives the permissions of that class.

To handle deadlocks in application programs, operating systems most often ____. A) assume that deadlocks never occur B) use protocols to prevent or avoid deadlocks C) detect and recover from deadlocks D) none fo the above

A) assume that deadlocks never occur

A shared file lock ____. A) behaves like a reader lock B) ensures that a file can have only on e concurrent shared lock. C) behaves like a writer lock D) can allow selected other processes to access the locked file.

A) behaves like a reader lock.

An exclusive file lock ___. A) behaves like a writer lock B) ensures that file can have only one concurrent shared lock C) behaves like a reader lock D) can allow selected other processes to access the locked file

A) behaves like a writer lock

Mechanism ____. A) determines how to do something. B) determines what will be done. C) should be coupled tightly to policy. D) is likely to change frequently.

A) determines how to do something

The most common technique for writing multithreaded Java programs is ____. A) implementing the Runnable interface and defining its run() method B) extending the thread class and overriding the run() method C) designing your own Thread class D) using the CreateThread() function

A) implementing the Runnable interface and defining its run() method

Thread-specific data is data that ____. A) is copied and not shared with the parent process. B) is not associated with any process. C) has been modified by the thread, but not yet updated to the parent process. D) is created by the parent process and shared with the threads.

A) is copied and not shared with the parent process.

A ___ virus changes each time it is installed to avoid detection by antivirus software A) polymorphic B) tunneling C) multipartite D) stealth

A) polymorphic