Operating Systems Ch 1

Front 1

Two units in a CPU

Back 1

1) Control Unit

2) Arithmetic and Logic Unit

Front 2

What connects to a CPU

Back 2

Input/Output, secondary and primary memory (RAM)

Front 3

Interrupt

Back 3

a signal that tells of a change in a program or hardware

Front 4

clock

Back 4

regular pulse that signals the beginning of an action

Front 5

address

Back 5

location within memory in bytes

Front 6

kinds of multiprocessor

Back 6

1) tightly coupled (shared clock & memory)

2) loosely coupled (each CPU is autonomous)

Front 7

kinds of tightly coupled processor

Back 7

1) symmetric multiprocessing: all working on same program

2) asymmetric multiprocessing: all working on one program

Front 8

goal of multiprogramming

Back 8

keep CPU busy at all times by swapping jobs in and out

Front 9

timesharing

Back 9

swap users in and out of CPU so all users can work seemingly simultaneously

Front 10

what does OS keep track of for process management?

Back 10

-address of program

-location of next instruction

-process table (current values)

-child processes

Front 11

mounting

Back 11

add (usually external) file system to current file system

Front 12

virtual machines

Back 12

run code independent of platform, like JVM (java virtual machine)

Front 13

two main functions of an operating system

Back 13

1) provide a layer of abstraction to users and applications to make them easier to use

2) handle resource allocation and usage, such as memory, processors, and input/output devices

Front 14

on early computers, every byte of data read or written was handled by CPU. what implications does this have for multiprogramming?

Back 14

multiprogramming would not be possible as we wouldn't be able to save midway values within memory, so we'd have to run everything sequentially

Front 15

two CPUs, each with two threads. Three programs, P0, P1, and P2, which each take 5, 10, and 20 msec, respectively. How long will execution of all three take?

Back 15

P0 and P1 on one CPU and P2 on the second, will take 20 msec

Front 16

Why are part of interrupt handlers written in assembly language?

Back 16

certain actions required of input handlers are unable to be performed by high level languages, and so must be done in assembly language. these actions include saving registers into the process table and setting the stack pointer

Front 17

formula for CPU utilization

Back 17

1-p^n where p = % time spent waiting for I/O to complete and n = number of processes

Front 18

.h files

Back 18

lists of declarations of variables and methods used in code files which can then be imported by compiler.

improves organization and removes redundancy in code

Front 19

.o files

Back 19

translated binary instructs of C++ code to be executed by CPU

Front 20

what does the preprocessor do when compiling C++ files?

Back 20

puts header files into .c files and turns into .o files

Front 21

what does the linker do when compiling C++ files?

Back 21

combines all .o files into one file, and makes adjustments so the output a.out file will be executable