CH3

Question 1

a program in execution; process execution must progress in sequential fashion

Answer 1

Process

Question 2

_________ is the part of the process which is the program code.

Answer 2

Text section

Question 3

_________ is the process part which contains temporary data such as function parameters, return addresses, and local variables.

Answer 3

Stack

Question 4

__________ is the process part which contains global variables, arrays, etc.

Answer 4

Data section

Question 5

________ is the process part which contains the memory dynamically allocating during run time.

Answer 5

Heap

Question 6

Program is (passive/active) entity stored on disk (executable file), process is (passive/active).

Answer 6

Program is passive.
process is active.

Question 7

Program becomes ________ when executable file loaded into memory.

Answer 7

process

Question 8

T/F: Execution of program started via GUI mouse clicks, command line entry of its name, etc.

Answer 8

True

Question 9

T/F: Each program can only be one process.

Answer 9

f, one program can be several processes; consider multiple users executing the same program

Question 10

A process needs to consist of four segments to be in memory: ________ segment, _______ segment, ________ segment, and __________ segment.

Answer 10

stack, heap, data, text.

Question 11

In a single-CPU system, only one process may be in ________ state.

Answer 11

running; many processes may be in ready and waiting states.

Question 12

As a process executes, it changes state into ________ when the process in being created.

Answer 12

new

Question 13

As a process executes, it changes state into ________ when instructions are being executed.

Answer 13

running

Question 14

As a process executes, it changes state into ________ when the process is waiting for some event to occur.

Answer 14

waiting

Question 15

As a process executes, it changes state into ________, when the process is waiting to be assigned to a processor.

Answer 15

ready

Question 16

As a process executes, it changes state into ________, when the process has finished execution.

Answer 16

terminated

Question 17

Process state change cycle continues until the process exists, falls, or is terminated, moves to _________ state.

Answer 17

terminated

Question 18

If the process is running and the core is needed (say for an interrupts), the process will return back to the __________ state.

Answer 18

ready

Question 19

The process is scheduled onto a core, when the core is available, it is now in a __________ state.

Answer 19

running

Question 20

Information associated with each process is called ___________

Answer 20

Task Control Block

Question 21

The Process Control Block (PCB) includes information about each process such as the process state, program ________, CPU _______, CPU ________ information, ___________ information, ____________ information, and ___________ status information.

Answer 21

program counter, CPU registers, CPU scheduling information, memory-management information, accounting information, I/O status information.

Question 22

The _________ indicates the location of the instruction to next execute.

Answer 22

Program Counter

Question 23

The ___________ shows the memory allocated to the process.

Answer 23

Memory-management information

Question 24

The __________ are the contents of all process-centric registers.

Answer 24

CPU registers

Question 25

The ____________ includes the priorities, scheduling queue pointers.

Answer 25

CPU scheduling information

Question 26

The ______________ indicates how much CPU used, clock time elapsed since start, and time limits.

Answer 26

Accounting information.

Question 27

The ______________ includes I/O devices allocated to process, and list of open files.

Answer 27

I/O status information

Question 28

___________ occurs when the CPU switches to another process, so the system must save the state of the old process, and load the saved state for the new process.

Answer 28

Context Switch

Question 29

T/F: The context of a process is represented in the PCB.

Answer 29

True.

Question 30

Context-switch time is _________.

Answer 30

Overhead. (meaning the system does no useful work while switching.)

Question 31

T/F: The higher complex the OS and the PCB, the faster the context switch.

Answer 31

F, the more complex the longer (slower) context switch.

Question 32

T/F: Context switching is time dependent on hardware support.

Answer 32

True. (Some hardware providdes multiple sets of registers per CPU, which leads to multiple contexts loaded at once.)

Question 33

During a context switch from P0 to P1, P0 will receive a _____________ or ________ while executing, which leads P1 to change from an idle state to a state of execution.

Answer 33

System call, interruption

Question 34

During a context switch from P0 to P1, the OS will _____________ into PCB__ and ___________ from PCB__.

Answer 34

save state into PCB0, and reload state from PCB1.

Question 35

During a context switch between P0 and P1, when P1 receives a system call or gets interrupted, it will save state into ______ and reload state from ________.

Answer 35

PCB1, PCB0.

Question 36

During the context switch between P0 and P1, when P1 is executing P0 will be ________ core and idle. Then the OS will put _______ onto the core, for it to continue execution while P1 is idle.

Answer 36

off, P0

Question 37

If there are multiple program counters per process, multiple locations can execute at once. There will be a need for multiple ________ of control.

Answer 37

Threads

Question 38

T/F: In case a process has multiple threads of execution, there MUST be storage for thread details, multiple program counters in PCB.

Answer 38

True.

Question 39

_____________________ is used to maximize CPU use, it quickly switches processes onto CPU for time sharing.

Answer 39

Process Scheduling

Question 40

__________ selects among available processes for next execution on CPU.

Answer 40

Process Scheduler.

Question 41

Process Scheduling maintains scheduling queues of processes, which are ________________, _____________, and __________.

Answer 41

Job queue, Ready queue, Device queue

Question 42

_______ queue includes the set of processes waiting for an I/O device.

Answer 42

Device

Question 43

__________ queue includes the set of all processes in the system.

Answer 43

Job

Question 44

_______ queue includes the set of all processes residing in main memory, ready, and waiting to execute.

Answer 44

Ready

Question 45

T/F: Processes cannot migrate among the various queues.

Answer 45

F, they can and they do.

Question 46

_______________ selects which process should be executed next and allocates CPU.

Answer 46

Short-term Scheduler

Question 47

Short-term scheduler is also called __________ scheduler

Answer 47

CPU

Question 48

T/F: Sometimes the longterm scheduler is the only scheduler in a system.

Answer 48

F, Short-term scheduler not long-term

Question 49

T/F: Short-term scheduler is invoked frequently (milliseconds) therefore it must be fast.

Answer 49

True.

Question 50

______________ selects which processes should be brought into the ready queue.

Answer 50

Long-term Scheduler

Question 51

Long-term scheduler is also called _________ scheduler.

Answer 51

Job

Question 52

Long-term scheduler is invoked (frequently/infrequently)

Answer 52

infrequently (seconds, minutes) so it may be slow.

Question 53

The long-term scheduler controls the degree of ______________.

Answer 53

multiprogramming.

Question 54

The number of processors in memory is the ___________________.

Answer 54

degree of multiprogramming

Question 55

______________ is the execution of the program in CPU between two I/O requests (i.e. time period during which the process wants to continuously run in the CPU without making I/O.)

Answer 55

CPU burst

Question 56

Processes can be described as either _____________ process or _________ process.

Answer 56

I/O bound, CPU-bound

Question 57

(I/O bound, CPU-bound) process spends more time doing computations; few very long CPU bursts.

Answer 57

CPU-bound

Question 58

(I/O bound, CPU-bound) process spends more time doing I/O than computations, many short CPU bursts.

Answer 58

I/O bound

Question 59

T/F: Long-term scheduler strives for good process mix.

Answer 59

True.

Question 60

_______________ scheduler can be added if degree of multiple programming needs to decrease.

Answer 60

Medium-term

Question 61

__________ occurs when a process is removed from memory, stored on disk, brought back in from disk to continue execution.

Answer 61

Swapping

Question 62

T/F: The medium-term scheduler performs swapping.

Answer 62

True.

Question 63

A _______ process creates children processes, which, in turn create other processes, forming a _______ of processes

Answer 63

Parent, tree.

Question 64

Generally, process identified and managed via a _______________.

Answer 64

process identifier (pid)

Question 65

T/F: Parent and children process can either share all resources or no resources at all.

Answer 65

True

Question 66

T/F: Parent process can share a subset of children's resources.

Answer 66

F, Child process shares a subset of PARENT's resources.

Question 67

T/F: Parent and child process cannot execute concurrently.

Answer 67

F, They do.

Question 68

T/F: Parent process waits until children terminate, so it can execute.

Answer 68

True.

Question 69

_________ is a system call used after a fork() to replace the process' memory space with a new program.

Answer 69

exec()

Question 70

______ is a system call creates new process.

Answer 70

fork()

Question 71

During process Termination, the process executes its last statement and then asks the operating system to delete it using the _________ system call.

Answer 71

exit()

Question 72

Process termination returns status data from child to parent via _______ system call.

Answer 72

wait()

Question 73

T/F: Process Termination results in the process’ resources being deallocated by the operating system.

Answer 73

True.

Question 74

Parent may terminate the execution of children processes using the ______ system call.

Answer 74

abort()

Question 75

T/F: Parent process may abort child process because child has exceeded allocated resources.

Answer 75

True.

Question 76

T/F: Parent process may abort child process because task assigned to child is no longer required.

Answer 76

True.

Question 77

T/F: Some operating systems do not allow child to exists if its parent has terminated. If a process terminates, then all its children must also be terminated.

Answer 77

True.

Question 78

_______________ occurs when all children, grandchildren, etc. are terminated.

Answer 78

cascading termination

Question 79

Cascading termination is initiated by the (parent process/operating system).

Answer 79

operating system.

Question 80

The parent process may wait for termination of a child process by using the _______ system call.

Answer 80

wait()

Question 81

When the parent process waits for the process termination of a child, the wait() system call returns ____________ and ___________ of the terminated process.

Answer 81

status information, the pid.

Question 82

(Independent/Cooperating) process cannot affect or be affected by the execution of another process. (Independent/Cooperating) process can affect or be affected by the execution of another process.

Answer 82

Independent Cooperating

Question 83

T/F: Processes within a system may be independent or cooperating.

Answer 83

True.

Question 84

_____________ and ____________ are the two models of IPC.

Answer 84

Shared memory, Message passing.

Question 85

Cooperating processes require a facility/mechanism for ________________________ (IPC)

Answer 85

interprocess communication

Question 86

During shared memory IPC, A region of shared memory is established among ____________ processes.

Answer 86

two or more

Question 87

During shared memory IPC, the establishment of that shared region is done via the help of the _________(via a system call).

Answer 87

kernel

Question 88

T/F: During Shared memory IPC, processes read and write shared memory region indirectly as ordinary memory access.

Answer 88

False, directly.

Question 89

T/F: During shared memory IPC, the kernel is NOT involved when the processes are reading and and writing the shared memory.

Answer 89

T, communication is under the control of the users processes not the operating system

Question 90

T/F: Message passing is faster than shared memory IPC.

Answer 90

F, Shared memory is faster.

Question 91

When solving the Producing-Consumer problem using shared memory IPC, there can be two types of buffers used; _________ which places no practical limit on the size of the buffer and ________ which assumes that there is a fixed buffer size.

Answer 91

unbounded-buffer, bounded-buffer.

Question 92

When an unbounded buffer is used for shared memory IPC, both the consumer and producer must wait.

Answer 92

False, when an bounded buffer is used the consumer must wait if the buffer is empty, produce will wait if the buffer is full. Only the consumer may have to wait for new items when the an unbounded buffer is used.

Question 93

T/F: During shared memory IPC, the producer and consumer do not need to be synchronized.

Answer 93

F, The producer and consumer must be synchronized, so that the consumer does not try to consume an item that has not yet been produced.