Processes Flashcards
What does a multiprogramming system, from a high level context, do?
In the space of a second, the CPU is able to switch and work on multiple different things.
What word is used to describe the apparent appearance of parallelism? What does it describe?
Pseudo-parallelism.
It describes the appearance of actual parallelism whereby multiple processes are being handled by multiple CPUs
What is a process? What three things does it contain?
An executing program.
Contains registers, program counter and variables.
What’s the difference between a process and a program?
Cooking.
A recipe, a set of instructions, is a program.
The process are the activities which feed into (eyyy) the recipe.
Give an analogy for a process switch for baking
Cook's son comes into kitchen with bee sting. Cook bookmarks recipe page. Cook sorts out son. Cook gets back to recipe page. Cook continues cooking.
What four things cause a process to be created?
System initilsation
Execution of a process creation system call by a running process
A user request to create a new process
Initiation of a batch job
What are daemons?
Processes that ‘stay in the background’.
Give examples of daemon processes
Accepting incoming email.
Accepting incoming requests for a website.
What is system initilisation processes?
The first processes when starting a computer.
Give an example of when a process might be created by another process?
Large amount of data being collected through a network.
Setting up a process that takes the data and places it in a shared buffer.
Setting up another process and having that work upon the data.
How might you make a process created by another process run faster?
On a multiprocessor system, running a process that is independent of but related to (in a holistic sense) the first process on another CPU could make the program run faster.
Give an example of an interactive system process being created?
User typing a command or clicking an icon.
Give four examples of how processes terminate
Normal exit
Error exit
Fatal error
Killed by another process
Which two process termination examples are voluntary
Normal exit
Error exit
Which two process termination examples are involuntary
Fatal error
Killed by another process