what are the key management tasks of an OS
- provision of a user interface
- provision of a software platform
- memory management
- file management
- security management
- process management
- hardware management
- error checking and recovery
how does the os manage memory
- allocates memory to processes and keeps track of memory locations
- manages paging, segmentation, and virtual memory // moves data from secondary storage when needed
- reclaims unused blocks of memory (RAM)
- prevents two programs from occupying the same area of RAM at the same time.
a user interface allows…
a user to communicate with the hardware
file management
- creates files/folders
- renames files
- controls access
security management
- Creates accounts/passwords
- Checks access rights and prevents unauthorized access
- Provides recovery for lost data
- Ensures data privacy
- Provide anti-malware
process management
- Decides which process to run next
- Supports multitasking
- Handles priorities
utility software
- disk formatter
- virus checker
- disk repair software / disk contents analysis
- back-up software
- disk defragmenter
- file compression
virus checker
- Checks for and then removes any viruses found
- Constantly checks all incoming and outgoing files
disk formatter
- Prepare a disk for initial use
- checks all sectors and marks bad sectors.
- Makes existing data inaccessible
disk repair
- To check for and fix inconsistencies on a disk
- Checks for and marks any errors/bad sectors on the disk
- Resolves any errors on the disk
back-up software
- to make a copy of data at regular intervals
- so that if it lost it can be retrieved
defragmentation software
- Reorganizes disk contents into contiguous memory sectors
- Improve disk access times // Data/files can be loaded faster
- defragmentation also creates larger contiguous free space regions
fragmentation
contents of file scattered across multiple sectors. fragmentation slows down computer performance and speed of file access
what is a DLL?
- A shared library file
- Code is saved separately from the main .EXE files
- Code is only loaded into main memory when required at run-time
- The DLL file can be made available to several applications at the same time.
features of an IDE
- Context sensitive prompts
- Syntax checking
- Pretty printing
- Single-stepping
- Breakpoints
- report/watch window
- compiler/interpreter
context sensitive prompts
Displays a list of keywords or prompts that could be used
dynamic syntax checks
errors are underlined by the IDE
prettyprinting
involves color coordinated code, indentation, and built-in functions like def(). is used to make the groups of code more identifiable, and easier to code.
collapsing code blocks
collapsing massive chunks of code
single-stepping
you can execute a single node at a time, causing the program to pause after the node completes
breakpoints
The breakpoint ends the program
report window
shows how variables change in the program
assembler
translates low-level code (assembly language) into machine code
compiler benefits
these are also the features
Produces an executable file
User does not have access to source code
It will (probably) be faster to run the executable code
Code does not have to be compiled each time it is run
Does not need the compiler to be present at run-time
