OS

The maximum number of bytes that can be allocated to a single file in UNIX is ____.

1,082,201,088

A general rule of thumb for selecting a proper time quantum in Round Robin scheduling is that it should be long enough to allow ____ percent of the CPU cycles to run to completion

80

Assume that four jobs, A-D, are in the READY queue at Time 0 and require the CPU cycles listed below. Using the SJN algorithm, the ____ job is run first. Job: A B C D CPU cycle: 5 2 6 4

B

____ developed the Banker's Algorithm.

Dijkstra

____ is a dynamic-priority preemptive scheduling algorithm built to address the critical processing requirements of real-time systems and their pressing deadlines.

Earliest Deadline First

The ____ is also called a high-level scheduler.

Job Scheduler

In a paged memory allocation scheme, the ____ contains two values for each active job: the size of the job and the memory location where its Page Map Table is stored.

Job Table

The transition from ____ can be initiated by the Process Scheduler or the Job Scheduler.

RUNNING to FINISHED

The Java ____ class is a collection of methods used to start, run, stop, and check the status of a thread.

Thread

Each thread in a process is represented by a data structure called a ____ that contains basic information such as the thread's unique identification, state, and priority.

Thread Control Block

____ allows for faster turnaround of CPU-bound jobs.

Variable time quantum per queue

When using the WAIT and SIGNAL operations, ____ sets the process's process control block to the blocked state and links it to the queue of processes waiting to enter this particular critical region.

WAIT

There is no return from a successful ____ call.

exec

A race introduces the element of chance, which is a highly desirable attribute, in database management.

false

According to the Banker's Algorithm, an unsafe state always leads to deadlock.

false

Cache memory is based on the concept of using a large, fast, and expensive memory to supplement the workings of main memory.

false

Dual core or quad core multi-core chips are larger than a single-processor chip but produce less current leakage and heat.

false

In a demand paging scheme, the first-in first-out (FIFO) page replacement policy chooses the page least recently accessed to be swapped out.

false

In a loosely coupled system, a job may move from one processor to another during execution.

false

In parallel computations, mutual exclusion is achieved automatically because each operation is handled in order, one at a time.

false

In the dining philosophers problem, there are five philosophers and four forks.

false

Starvation is the result of a policy that liberally allocates resources.

false

The Processor Manager is a composite of at least two submanagers: one in charge of job scheduling and the other in charge of program scheduling.

false

The only tangible benefit of parallel processing systems is faster processing.

false

The success of process synchronization hinges on the capability of the operating system to make a resource available to other processes while it is being used by one of them.

false

UNIX can be mastered by novice programmers in a matter of weeks.

false

To access a location in memory when using segmented memory management, the address is composed of two entries: ____.

he segment number and the displacement

No movement between queues is a very simple policy that rewards those who have ____ jobs.

high-priority

The UNIX file management system organizes the disk into blocks of 512 bytes each and divides the disk into four basic regions, the first of which ____.

is reserved for booting

An I/O request is called a(n) ____ wait in multiprogramming environments.

natural

If a program's execution is expected to take a long time, you can start its execution and then log off the system without having to wait for it to finish by using the command ____.

nohup

A ____ is several programs simultaneously processing the same I/O stream.

pipeline

Failure to lock database records before updating them may result in a ____ between processes.

race

The ____ command is used to delete a file or directory.

rm

In demand paging schemes, the ____ in a Page Map Table indicates whether the page is currently in memory.

status bit

For multiprogramming systems, most UNIX operating systems use either ____ management techniques.

swapping or demand paging memory

The first and simplest recovery method, and the most drastic, is to ____.

terminate every job that's active in the system and restart them from the beginning

The operation P in a semaphore scheme requires a(n) ____ sequence to be performed as an indivisible action in a single machine cycle.

test, fetch, decrement, and store

UNIX uses a ____ to keep track of which processes are using shared program code.

text table

Deadlock can occur on a printer when ____.

the printer needs all of a job's output before it will begin printing, but the spooling system fills the available disk space with only partially completed output

A(n) ____ is created by a process, and it can be scheduled and executed independently of its parent process.

thread

____ semaphores are used in the producer and consumer problem.

three

A livelock can be caused by two processes accessing different areas of the same disk.

true

A pipe is the operating system's way to connect the output from one program to the input of another without the need for temporary or intermediate files.

true

Associative memory is a name given to several hardware registers that are allocated to each active job whose task is to associate segment and page numbers belonging to the job being processed with their main memory addresses.

true

Deadlock is a system-wide tangle of resource requests that begins when two or more jobs are put on hold, each waiting for a vital resource to become available.

true

Deadlock was a serious problem for early batch systems.

true

Demand paging introduced the concept of loading only a part of the program into memory for processing

true

In UNIX, swapping uses a round robin memory-management policy.

true

In UNIX, the process table is set up when the process is created and is deleted when the process terminates.

true

Java technology is used for many Web and Internet applications, and it integrates well with browsers that can run Java applets with audio, video, and animation directly in a Web page.

true

Multiprocessing can refer to one job using several processors to execute sets of instructions in parallel.

true

Once starvation has been detected, an algorithm can be implemented in which the system blocks new jobs until the starving jobs have been satisfied.

true

Resource holding, where a job holds on to one resource while waiting for another one that's not yet available, can be sidestepped by forcing each job to request, at creation time, every resource it will need to run to completion.

true

Shortest job next (SJN) is a nonpreemptive scheduling algorithm (also known as shortest job first, or SJF) that handles jobs based on the length of their CPU cycle time.

true

The classic problem of producers and consumers is one in which one or more processes produce some data that one or more processes consume later.

true

The exec family of commands—execl, execv, execle, execlp and execvp—is used to start execution of a new program from another program.

true

The key to the successful implementation of demand paging is the use of a high-speed CPU.

true

The primary advantage of storing programs in noncontiguous page frames (in a paged memory allocation scheme) is that main memory is used more efficiently because an empty page frame can be used by any page of any job.

true

Virtual memory can be implemented with both paging and segmentation.

true

When a programmer indicates in the code which instructions can be executed in parallel in a program (for example, using COBEGIN and COEND), it is called implicit parallelism.

true

In a paged memory allocation scheme, a page size that is too small will generate ____.

very long Page Map Tables

When the UNIX Processor Manager is deciding which process from the READY queue will be loaded into memory to be run first, it chooses the process ____.

with the longest time spent on the secondary storage

In demand paging, the collection of pages residing in memory that can be accessed directly without incurring a page fault is called the ____.

working set

In a paged memory allocation scheme, a simple ____ has one entry for each page frame that shows its location and its free/busy statu

Memory Map Table

Fill in the missing event that causes deadlock in a database. There are two processes (P1 and P2), each of which needs to update two records (R1 and R2) and the following sequence leads to a deadlock: 1. P1 accesses R1 and locks it. 2. P2 accesses R2 and locks it. 3. ____ 4. P2 requests R1, which is locked by P1.

P1 requests R2, which is locked by P2.

____ is a family of IEEE standards that define a portable operating system interface to enhance the portability of programs from one operating system to another.

POSIX

__ are the device drivers that provide the interface to I/O hardware.

Special files

____ is when, in modern printing systems, a disk accepts output from several users and acts as a temporary storage area for all output until the printer is ready to accept it.

Spooling

Fill in the missing event that causes livelock. At an insurance company, the system performs many daily transactions. One day, the following series of events ties up the system: 1. Process P1 wishes to show a payment, so it issues a command to read the balance, which is stored in cylinder 20 of a disk pack. 2. ____ 3. P2 gains control of the I/O channel and issues a command to write someone else's payment to a record stored in cylinder 310. If the command is not "locked out," P2 will be put on hold while the control unit moves the arm to cylinder 310. 4. Because P2 is "on hold," the channel is free to be captured again by P1, which reconfirms its command to "read from cylinder 20." 5. Since the last command from P2 had forced the arm mechanism to cylinder 310, the disk control unit begins to reposition the arm to cylinder 20 to satisfy P1. The I/O channel would be released because P1 is once again put on hold, so it could be captured by P2, which issues a WRITE command only to discover that the arm mechanism needs to be repositioned.

While the control unit is moving the arm to cylinder 20, P1 is put on hold and the I/O channel is free to process the next I/O request.

An algorithm designed to detect starvation by tracking how long each job has been waiting for resources is using the concept of ____.

aging

The first-come, first-served (FCFS) algorithm is fine for most ____ systems.

batch

The command, ____ , will copy the contents of chapt1 and chapt2 into a file named section_a.

cat chapt1 chapt2 > section_a

A ____ of processing must be handled as a single unit.

critical region