problems with insufficient resources Flashcards
what is batch processing
computer operation where some programs are batched together and executed as a group
how do programs run in batch processing
only one program runs at a time whilst others wait for their turn
what is multiprogramming
early form of parallel processing where several programs are run at the same time on a single processor
CPU executes the entire process before to execute the next waiting
what takes place in the memory during multiprogramming
two or more programs are loaded in the main memory - only one program is executed by the CPU at a time
what is the purpose of multiprogramming
to maximise the use of CPU time
what is a problem that has to be dealt with multiple programs residing in the main memory
memory fragmentation as programs are moved into and out of the memory
what is multitasking
tasks or processes (instead of programs) are run simultaneously and they share a common resource (eg. CPU)
how is multitasking quicker than multiprogramming
tasks are smaller than programs - this makes it appear as if the programs are all running at the same time
how does multitasking make best use of CPU resources
uses program fragments called processes
what is multiprocessing
means that a computer has more than one CPU core - refers to hardware
what is multithreading
ability of a program to execute different parts of the program (threads) at the same time
what do several threads of a single process share
they share the CPU in a single CPU system
they run in parallel in a multi core system
what is multiaccess
operation where a lot of users can interact with a one computer system using their terminals
what does multiaccess system require (4)
multiline communication capabilities that supports simultaneous dialogues with remote terminals
ability to instantly switch from executing one client’s program to executing another
ability to protect all data from unauthorized access
ability to quickly find and make all the data stored on the hard disk available
