Operating Systems and Software Development Concepts

Vocabulary flashcards reviewing core topics on operating systems, utility software, program libraries, language translators, and IDE features.

Why a computer system requires an Operating System

Provides an environment in which applications can run and acts as an interface between hardware and the user.

Five key management tasks of an OS

Memory management, File management, Security management, Hardware management, Process management.

Memory management

Allocates and protects memory so two applications cannot use the same memory locations at the same time.

File management

Maintains directory structures, file naming conventions and access rights.

Security management

Ensures integrity, confidentiality and availability of data using passwords, access rights and updates.

Hardware management

Controls input/output devices using device drivers, queues and buffers.

Process management

Allocates resources and schedules processes so they can run without conflict.

Six utility programs provided by an OS

Disk formatter, virus checker, defragmentation software, disk contents analysis/repair software, file compression, back-up software.

Disk formatter

Prepares a disk for use by creating partitions and detecting bad sectors.

Defragmentation software

Rearranges scattered file blocks into contiguous sectors so that access is faster.

Virus checker

Detects, quarantines and removes malware. Uses a database of known viruses and heuristic checking.

Program library

A collection of pre-written and tested routines that programmers can use in their own programs.

Benefits of using library routines

Saves development time and the routines are already tested (fewer errors).

DLL (Dynamic Link Library)

A library routine that is linked to a program only at run-time.

Benefits of using DLL files

Main program is smaller and the same DLL can be shared by many programs.

Drawback of using DLL files

If the DLL is missing or changed, the program may not run or may crash.

Assembler

Translates assembly language into machine code (one-to-one translation).

Compiler

Translates a whole high-level language program into machine code (or object code) before it is run.

Interpreter

Translates and executes a high-level language program line by line.

Advantages of a compiler over an interpreter

Faster execution and the source code is protected (user only receives the executable).

Advantages of an interpreter over a compiler

Easier to debug (stops at the first error) and useful during development and testing.

How Java programs are translated

Partially compiled into bytecode, then interpreted (or JIT-compiled) by a virtual machine.

Four useful features of an IDE

1. Context-sensitive prompts 2. Dynamic syntax checking 3. Prettyprinting / expand-collapse code blocks 4. Single-stepping, breakpoints and variable report window