OPERATING SYSTEMS QUIZ 2

process

a _______ is a program in execution; execution must progress in a sequential fashion. no parallel execution of instructions of a single ______.

text section

program counter

stack

data section

heap

multiple parts of a process

text section

the program code part of the process

program counter

part of the process; current activity including _____, processor registers

stack

part of the process; contains temporary data; function parameters, return addresses, local variables

data section

part of the process; contains global variables

heap

part of the process; containing memory dynamically allocated during run time

passive, active

prorgam is ______ entitty stored on disk (executable file); process is _______

loaded into memory

program becomes process when an executable file is ___________

GUI mouse clicks, command line entry of name

execution of program can start with _____________________, _____________, etc.

one, several

______ can be ________ processes

stack, heap, data, text

argc, argv

stack

heap

uninitialized data

initialized data

text

new, running, waiting, ready, terminated

as a process executes, it changes states:

new

process state; the process is being created

running

process state; instructions are being executed

waiting

process state; the process is waiting for some event to occur

ready

process state; the process is waiting to be assigned to a processor

terminated

process state; the process has finished execution

new, ready, waiting, running, terminated

diagram of process state

task control block

information associated with each process

process state

program counter

CPU registers

CPU scheduling information

memory-management information

accounting information

I/O status information

process control blocks

process state

process control block

running, waiting, etc.

program counter

process control block

location of instruction to next execute

CPU registers

process control block

contents of all process-centric registers

CPU scheduling information

process control block

priorities, scheduling, queue pointers

memory-management information

process control block

memory allocated to the process

accounting information

process control block

CPU used, clock time elapsed since start, time limits

I/O status information

process control block

I/O devices allocated to process, list of open file

single thread

so far, process has a _____ of execution

process representation in linux

process scheduler

selects among available processes for next execution on CPU core

maximize CPU use and quickly switch processes onto CPU core

ready queue

wait queue

role of process scheduling;

maintains the scheduling queues of processes

ready queue

set of all processes residing in main memory, ready, and waiting to execute

wait queue

set of processes waiting for an event (i.e. I/O)

ready and wait queues

representation of process scheduling

CPU switch from process to process

save the state

save state

context switch

when the CPU switches to another process, the sustem must _________ of the old process and load the _______ for the new process via a __________.

foreground process

controlled via user interface

background processes

in memory, running but not on the display, and with limits

process creation

process termination

systems must provide mechanisms for

parent

children

tree

_____ process create _______ process which, in turn, create other processes, forming a ______ of processes

process identifier (PID)

process is identified and managed via ________

UNIX process creation

linux tree processes

cascading termination

if a process terminates, then all of its children must also be terminated

all children, grandchildren, etc are terminated initiated by the OS

foreground

visiible

service

background

empty

most to least important android process importance hierarchy

independent or cooperating

processes within a system

information sharing

computation speedup

modularity

convenience

reasons for cooperating processes

interprocess communication (IPC)

cooperating processes need

shared memory

message passing

two models of interprocess communication (IPC)

shared memory

message passing

unbounded buffer

places no practical limit on the size of the buffer:

producer never waits

consumer waits if there is no buffer to consume

bounded-buffer

assumes that there is a fixed buffer size:

producers must wait if all buffers are full

consumer waits if there is no buffer to consume