Test
Operating Systems Final
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Preguntas del test (82)
1The most common secondary storage device is ____.
- Atape drives
- Bsolid state disks
- Crandom access memory
- Dmagnetic disk
2A ____ can be used to prevent a user program from never returning control to the operating system.
- Aprogram counter
- Btimer
- Cfirewall
- Dportal
3A clustered system ____.
- Ais used when rigid time requirements are present
- Bis an operating system that provides file sharing across a network
- Ccan only operate one application at a time
- Dgathers together multiple CPUs to accomplish computational work
4Which of the following is a property of peer-to-peer systems?
- ASeparate machines act as either the client or the server but not both.
- BThey do not offer any advantages over traditional client-server systems.
- CThey suffer from the server acting as the bottleneck in performance.
- DClients and servers are not distinguished from one another.
5A(n) ________ is the unit of work in a system.
- Amode bit
- Btimer
- Coperating system
- Dprocess
6The two separate modes of operating in a system are
- Auser mode and kernel mode
- Bphysical mode and logical mode
- Ckernel mode and privileged mode
- Dsupervisor mode and system mode
7A _____ is an example of a systems program.
- AWeb browser
- Bdatabase system
- Ccommand interpreter
- Dtext formatter
8If a program terminates abnormally, a dump of memory may be examined by a ____ to determine the cause of the problem.
- Ashell
- Bcontrol card
- Cmodule
- Ddebugger
9 message-passing model is ____.
- Aa network protocol, and does not apply to operating systems
- Bonly useful for small simple operating systems
- Ceasier to implement than a shared memory model for intercomputer communication
- Dfaster than the shared memory model
10Policy ____.
- Adetermines how to do something
- Bdetermines what will be done
- Cis not likely to change over time
- Dis not likely to change across places
11The major difficulty in designing a layered operating system approach is ____.
- Amaking sure each layer is easily converted to modules
- Bdebugging a particular layer
- Cappropriately defining the various layers
- Dmaking sure that each layer hides certain data structures, hardware, and operations from higher-level layers
12A microkernel is a kernel ____.
- Athat is compressed before loading in order to reduce its resident memory size
- Bthat is stripped of all nonessential components
- Ccontaining many components that are optimized to reduce resident memory size
- Dthat is compiled to produce the smallest size possible when stored to disk
13To the SYSGEN program of an operating system, the LEAST useful piece of information is _____.
- Aamount of memory available
- Bthe CPU being used
- Cwhat applications to install
- D
operating-system options such as buffer sizes or CPU scheduling algorithms
14A boot block ____.
- Atypically only knows the location and length of the rest of the bootstrap program
- Bis composed of multiple disk blocks
- Ctypically is sophisticated enough to load the operating system and begin its execution
- Dis composed of multiple disk cylinders
15_____ provide(s) an interface to the services provided by an operating system.
- ACommunication
- BSystem calls
- CSimulators
- DShared memory
16_____ is NOT one of the major categories of system calls.
- AProtection
- BSecurity
- CCommunications
- DProcess control
17_____ allow operating system services to be loaded dynamically.
- AModules
- BVirtual machines
- CFile systems
- DGraphical user interfaces
18Microkernels use _____ for communication.
- Avirtualization
- Bmessage passing
- Cshared memory
- Dsystem calls
19Android runs Java programs _____________
- Anatively.
- Bin the Java virtual machine.
- CAndroid does not run Java programs.
- Din the Dalvik virtual machine.
20______ is a mobile operating system designed for the iPhone and iPad.
- AiOS
- BMac OS X
- CAndroid
- DUNIX
21_____ is/are NOT a technique for passing parameters from an application to a system call.
- ASpecial block in memory
- BCache memory
- CStack
- DRegisters
22An initial bootstrap program is in the form of random-access memory (RAM).
- AVerdadero
- BFalso
23System calls can be run in either user mode or kernel mode.
- AVerdadero
- BFalso
24Application programmers typically use an API rather than directly invoking system calls.
- AVerdadero
- BFalso
25Mac OS X is a hybrid system consisting of both the Mach microkernel and BSD UNIX.
- AVerdadero
- BFalso
26The ____ of a process contains temporary data such as function parameters, return addresses, and local variables.
- Adata section
- Bprogram counter
- Cstack
- Dtext section
27A process control block ____.
- Aincludes information on the process's state
- Bdetermines which process is to be executed next
- Cis an example of a process queue
- Dstores the address of the next instruction to be processed by a different process
28The list of processes waiting for a particular I/O device is called a(n) ____.
- Ainterrupt queue
- Bready queue
- Cdevice queue
- Dstandby queue
29When a child process is created, which of the following is a possibility in terms of the execution or address space of the child process?
- AThe child process runs concurrently with the parent.
- BThe child process has a new program loaded into it.
- CThe child is a duplicate of the parent.
- DAll of the above
- ENone of the above
30A _________________ saves the state of the currently running process and restores the state of the next process to run.
- A
context switch - Bstate switch
- Cmutex switch
- Dsave-and-restore
- A
31A process may transition to the Ready state by which of the following actions?
- ACompletion of an I/O event
- BAwaiting its turn on the CPU
- CNewly-admitted process
- DAll of the above
- EA and C only
32In a(n) ____ temporary queue, the sender must always block until the recipient receives the message.
- Avariable capacity
- Bbounded capacity
- Cunbounded capacity
- Dzero capacity
33A blocking send() and blocking receive() is known as a(n) _________________
- Aasynchronous message
- Bsynchronized message
- Crendezvous
- Dblocked message
34A(n) ______________ allows several unrelated processes to use the pipe for communication.
- Anamed pipe
- Banonymous pipe
- CLIFO
- Dordinary pipe
35Which of the following statements is true?
- AMessage passing is typically faster than shared memory.
- BMessage passing is most useful for exchanging large amounts of data.
- CShared memory is far more common in operating systems than message passing.
- DShared memory is typically faster than message passing.
36Imagine that a host with IP address 150.55.66.77 wishes to download a file from the web server at IP address 202.28.15.123. Select a valid socket pair for a connection between this pair of hosts.
- A150.55.66.77:80 and 202.28.15.123:3500
- B150.55.66.77:80 and 202.28.15.123:80
- C150.55.66.77:2000 and 202.28.15.123:80
- D150.55.66.77:150 and 202.28.15.123:80
37Which of the following statements is true?
- AOnly the parent and child processes can use named pipes for communication.
- BReading and writing to ordinary pipes on both UNIX and Windows systems can be performed like ordinary file I/O.
- CNamed pipes can only be used by communicating processes on the same machine.
- DNamed pipes do not allow bi-directional communication.
38A process that has terminated, but whose parent has not yet called wait(), is known as a ________ process.
- Aterminated
- Bzombie
- Corphan
- Dinit
39The ____ multithreading model multiplexes many user-level threads to a smaller or equal number of kernel threads.
- Aone-to-one model
- Bmany-to-many model
- Cmany-to-some model
- Dmany-to-one model
40Which of the following would be an acceptable signal handling scheme for a multithreaded program?
- ADeliver the signal to the thread to which the signal applies.
- BDeliver the signal to every thread in the process.
- CDeliver the signal to only certain threads in the process.
- DAll of the above
- ENone of the above
41Thread-local storage is data that ____.
- Ais generated by the thread independent of the thread's process
- Bhas been modified by the thread, but not yet updated to the parent process
- Cis unique to each thread
- Dis not associated with any process
42_____ is not considered a challenge when designing applications for multicore systems.
- ADetermining if data can be separated so that it is accessed on separate cores
- BDeciding which activities can be run in parallel
- CIdentifying data dependencies between tasks.
- DEnsuring there is a sufficient number of cores
43A ____ provides an API for creating and managing threads.
- Aset of system calls
- Bmulticore system
- Cmultithreading model
- Dthread library
44The _____ model maps each user-level thread to one kernel thread.
- Amany-to-many
- Btwo-level
- Cmany-to-one
- Done-to-one
45A _____ uses an existing thread — rather than creating a new one — to complete a task.
- Athread pool
- Bscheduler activation
- Clightweight process
- Dasynchronous procedure call
46_________ involves distributing tasks across multiple computing cores.
- ATask parallelism
- BConcurrency
- CData parallelism
- DParallelism
47A ____ provides an API for creating and managing threads.
- Aset of system calls
- Bthread library
- Cmultithreading model
- Dmulticore system
48The _____ model maps many user-level threads to one kernel thread.
- Aone-to-one
- Bmany-to-many
- Ctwo-level
- Dmany-to-one
49A race condition ____.
- Aresults when several threads try to access and modify the same data concurrently
- Bresults when several threads try to access the same data concurrently
- Cwill result only if the outcome of execution does not depend on the order in which instructions are executed
- DNone of the above
50A counting semaphore ____.
- Ais essentially an integer variable
- Bcannot be used to control access to a thread's critical sections
- Cis accessed through only one standard operation
- Dcan be modified simultaneously by multiple threads
51A mutex lock ____.
- Ais not guaranteed to be atomic
- Bis exactly like a counting semaphore
- Ccan be used to eliminate busy waiting
- Dis essentially a boolean variable
52A ___ type presents a set of programmer-defined operations that are provided mutual exclusion within it.
- Atransaction
- Bsignal
- Cmonitor
- Dbinary
53____________ occurs when a higher-priority process needs to access a data structure that is currently being accessed by a lower-priority process.
- AA critical section
- BDeadlock
- CA race condition
- DPriority inversion
54What is the correct order of operations for protecting a critical section using mutex locks?
- Aacquire() followed by release()
- Brelease() followed by acquire()
- Cwait() followed by signal()
- Dsignal() followed by wait()
55A solution to the critical section problem does not have to satisfy which of the following requirements?
- Aprogress
- Bmutual exclusion
- Cbounded waiting
- Datomicity
56A(n) _______ refers to where a process is accessing/updating shared data.
- Aentry section
- Bmutex
- Ctest-and-set
- Dcritical section
57_____ can be used to prevent busy waiting when implementing a semaphore.
- ASpinlocks
- BAllowing the wait() operation to succeed
- CWaiting queues
- DMutex lock
58Race conditions are prevented by requiring that critical regions be protected by locks.
- AVerdadero
- BFalso
59Which of the following is true of cooperative scheduling?
- AA process keeps the CPU until it releases the CPU either by terminating or by switching to the waiting state.
- BIt incurs a cost associated with access to shared data.
- CIt requires a timer.
- DA process switches from the running state to the ready state when an interrupt occurs.
60____ is the number of processes that are completed per time unit.
- AResponse time
- BCPU utilization
- CThroughput
- DTurnaround time
61____ scheduling is approximated by predicting the next CPU burst with an exponential average of the measured lengths of previous CPU bursts.
- AMultilevel queue
- BRR
- CSJF
- DFCFS
62The ____ scheduling algorithm is designed especially for time-sharing systems.
- ARR
- BFCFS
- CMultilevel queue
- DSJF
63Which of the following scheduling algorithms must be nonpreemptive?
- ARR
- BSJF
- CFCFS
- Dpriority algorithms
64Which of the following is true of multilevel queue scheduling?
- AProcesses can move between queues.
- BIt is the most general CPU-scheduling algorithm.
- CA queue cannot have absolute priority over lower-priority queues.
- DEach queue has its own scheduling algorithm.
65______ allows a thread to run on only one processor.
- AProcessor set
- BNUMA
- CProcessor affinity
- DLoad balancing
66__________ involves the decision of which kernel thread to schedule onto which CPU.
- ARound-robin scheduling
- BSystem-contention scope
- CDispatcher
- DProcess-contention scope
67With _______ a thread executes on a processor until a long-latency event (i.e. a memory stall) occurs.
- Afine-grained multithreading
- Bcoarse-grained multithreading
- Cvirtualization
- Dmulticore processors
68A significant problem with priority scheduling algorithms is _____.
- Acomplexity
- Bdetermining the length of the time quantum
- Cstarvation
- Ddetermining the length of the next CPU burst
69The ______ occurs in first-come-first-served scheduling when a process with a long CPU burst occupies the CPU.
- Aconvoy effect
- Bdispatch latency
- Cwaiting time
- Dsystem-contention scope
70Which of the following is true of the rate-monotonic scheduling algorithm?
- ACPU utilization is bounded when using this algorithm.
- BIt uses a dynamic priority policy.
- CThe task with the shortest period will have the lowest priority.
- DIt is non-preemptive.
71Which of the following is true of earliest-deadline-first (EDF) scheduling algorithm?
- ADeadlines are assigned as following: the earlier the deadline, the lower the priority; the later the deadline, the higher the priority.
- BWhen a process becomes runnable, it must announce its deadline requirements to the system.
- CPriorities are fixed; that is, they cannot be adjusted when a new process starts running.
- DIt assigns priorities statically according to deadline.
72The two general approaches to load balancing are __________ and ____________.
- Asoft affinity, hard affinity
- Bcoarse grained, fine grained
- Cpush migration, pull migration
- Dsoft real-time, hard real-time
73A deadlocked state occurs whenever ____.
- Aa process is unable to release its request for a resource after use
- Ba process is waiting for I/O to a device that does not exist
- Cthe system has no available free resources
- Devery process in a set is waiting for an event that can only be caused by another process in the set
- Aa process is unable to release its request for a resource after use
74One necessary condition for deadlock is ____, which states that at least one resource must be held in a nonsharable mode.
- Amutual exclusion
- Bhold and wait
- Ccircular wait
- Dno preemption
75One necessary condition for deadlock is ______, which states that a process must be holding one resource and waiting to acquire additional resources.
- Amutual exclusion
- Bno preemption
- Ccircular wait
- Dhold and wait
76One necessary condition for deadlock is ______, which states that a resource can be released only voluntarily by the process holding the resource.
- Ano preemption
- Bmutual exclusion
- Ccircular wait
- Dhold and wait
77One necessary condition for deadlock is ______, which states that there is a chain of waiting processes whereby P0 is waiting for a resource held by P1, P1 is waiting for a resource held by P2, and Pn is waiting for a resource held by P0.
- Acircular wait
- Bno preemption
- Cmutual exclusion
- Dhold and wait
78In a system resource-allocation graph, ____.
- Aa directed edge from a process to a resource is called an assignment edge
- Ba directed edge from a resource to a process is called a request edge
- Ca directed edge from a process to a resource is called a request edge
- DNone of the above
79A cycle in a resource-allocation graph is ____.
- Aa necessary and sufficient condition for deadlock in the case that each resource has more than one instance
- Ba sufficient condition for a deadlock in the case that each resource has more than once instance
- Ca necessary and sufficient condition for a deadlock in the case that each resource has exactly one instance
- Dis neither necessary nor sufficient for indicating deadlock in the case that each resource has exactly one instance
80In relation to deadlocks, operating systems most often _____.
- Apretend that deadlocks never occur
- Buse protocols to prevent or avoid deadlocks
- Cdetect and recover from deadlocks
- DNone of the above
81Which of the following statements is true?
- AAn unsafe state may lead to a deadlocked state.
- BA safe state may lead to a deadlocked state.
- CA safe state is a deadlocked state.
- DAn unsafe state is necessarily, and by definition, always a deadlocked state.
82Which of the following data structures in the banker's algorithm is a vector of length m, where m is the number of resource types?
- AMax
- BAvailable
- CAllocation
- DNeed
Información
- Descripción
- Test sobre Operating Systems Final, creado por Kyllian Mobley el 13/05/2015.
- Autor
- Kyllian Mobley
- Idioma
- English
- Visitas
- 3
- Valoración
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