CSE 330 Exam 1

Operating System

-Controls and coordinates use of hardware among various applications and users -Interrupt-driven

Process Management Activities

-Creating and deleting both user and system processes -Suspending and resuming processes -Providing mechanisms for process synchronization -Providing mechanisms for process communication -Providing mechanisms for deadlock handling

Operating System Goals

-Execute user programs and make solving user problems easier -Make the computer system convenient to use -Use the computer hardware in an efficient manner

Memory Management Activities

-Keeping track of which parts of memory are currently being used and by whom -Deciding which processes (or parts thereof) and data to move into and out of memory -Allocating and deallocating memory space as needed

Bootstrap Program

-Loaded at power-up or reboot -Typically stored in firmware -Initializes al aspects of the system -Loads operating system kernel and starts execution

Resource Allocator

-Manages all resources -Decides between conflicting requests for efficient and fair resource use

Process

-Program in execution -Active Entity

Direct Memory Access Structure

-Used for high-speed I/O devices able to transmit information at close to memory speeds -Device controller transfers blocks of data from buffer storage directly to main memory without CPU intervention -Only one interrupt is generated per block, rather than the one interrupt per byte

Hardware, Operating System, Application Programs, and Users

4 Components of the Computer

Jobs

A batch system executed by the operating system

Process

A program in execution; execution must progress in sequential fashion

Operating System

A program that acts as an intermediary between a user of a computer and the computer hardware.

I/O operations

A running program may require I/O, which may involve a file or an I/O device

User programs/tasks

A time-shared system executed by the operating system

Pipes

Acts as a conduit allowing two processes to communicate

Dual-mode operation

Allows OS to protect itself and other system components

Virtual Memory

Allows execution of processes not completely in memory

Communication Link

Allows two process to communicate with one another

Privilege escalation

Allows user to change to effective ID with more rights

Protection

Any mechanism for controlling access of processes or users to resources defined by the OS

Bounded-buffer

Assumes that this a fixed buffer size

Named Pipes

Can be accessed without a parent-child relationship. Provided on both UNIX and Windows systems

Independent Processes

Cannot affect or be affected by the execution of another process

Ordinary Pipes

Cannot be accessed from outside the process that created it. Typically, a parent process creates a pipe and uses it to communicate with a child process that it created.

Stubs

Client-side proxy for the actual procedure on the server

Grub

Common bootstrap loader that allows a section of kernel from multiple disks, versions, or kernel options

Device-status Table

Contains entry for each I/O device indicating its type, address, and state

Data section

Contains global variables of a process

Heap

Contains memory dynamically allocated during run time

Stack

Contains temporary data of process: function parameters, return addresses, and local variables

Control Program

Controls execution of programs to prevent errors and improper use of the computer

Caching

Copying information into faster storage system; main memory can be viewed as a cache for secondary storage

Security

Defense of the system against internal and external attacks

Application Programs

Define the ways in which the system resources are used to solve the computing problems of the users -Word processors, compilers, web browsers, database systems, video games

Socket

Defined as an endpoint for communication. Concatenation of IP address and Port

Polling/vectored interrupt system

Determines which type of interrupt has occurred

Executable File

Disk that stores passive entity (program); process is active

Asymmetric Multiprocessing

Each processor is assigned a specific task

Symmetric Multiprocessing

Each processor performs all tasks

Secondary storage

Extension of main memory that provides large nonvolatile storage capacity

Solid-state disks

Faster than hard disks, nonvolatile

Performance Tuning

Improve performance by removing bottlenecks

Non-blocking

Is considered asynchronous where the sender or receiver is able to send and receive messages

Blocking

Is considered synchronous where the sender or the receiver is blocked

UNIX

Limited by hardware functionality. Consists of two separable parts: System programs and the kernel

Time-Sharing

Logical extension in which CPU switches jobs so frequently that users can interact with each job while it is running, creating interactive computing

Ports

Mailboxes form which messages are directed and received

Microkernel System

Moves as much from the kernel into user space.

Multiprogramming (Batch system)

Needed for efficiency

Sysgen Program

Obtains information concering the specific configuration of the hardware system

Main Memory

Only large storage media that the CPU can access directly

Layered Approach

Operating systems divided into layers. Starts at bottom layer(hardware) and goes up to user interface

Program

Passive Entity

Users

People, machines, other computers

Profiling

Periodic sampling of instruction pointer to look for statistical trends

Unbounded-buffer

Places no practical limit on the size of the buffer

Cooperating Processes

Process can affect of be affected by the execution of another process

Communication

Processes may exchange information, on the same computer or between computers over a network

Text Section

Program code of a process

Hardware

Provides basic computing resources -CPU, memory, I/O devices

Device Driver

Provides uniform interface between controller and kernel

Matchmaker

Rendezvous service to connect client and server

System Call

Request to the OS to allow user to wait for I/O completion

Hard Disk

Rigid metal or glass platters covered with magnetic recording material

Trap/Exception

Software-generated interrupt caused either by an error or a user request

Loopback

Special IP address to refer to system on which process is running

-Speed -Cost -Volatility

Storage Hierarchy

File-system manipulation

The file system is of particular interest. Programs need to read and write files and directories, create and delete them, search them, list file Information, permission management.

Program Execution

The system must be able to load a program into memory and to run that program, end execution, either normally or abnormally (indicating error)

Convenience, ease of use, and good performance

What do users want operating systems to do?

MS-DOS

Written to provide the most functionality in the least space -Not divided into modules