Process Management in Multi-tasking Operating Systems
A multitasking operating system may just switch between processes to give the appearance of many processes executing concurrently or simultaneously, though in fact only one process can be executing at any one time on a single-core CPU (unless using multithreading or other similar technology).
It is usual to associate a single process with a main program, and 'daughter' ('child') processes with any spin-off, parallel processes, which behave like asynchronous subroutines. A process is said to own resources, of which an image of its program (in memory) is one such resource. (Note, however, that in multiprocessing systems, many processes may run off of, or share, the same reentrant program at the same location in memory— but each process is said to own its own image of the program.)
Processes are often called "tasks" in embedded operating systems. The sense of "process" (or task) is "something that takes up time", as opposed to 'memory', which is "something that takes up space".
The above description applies to both processes managed by an operating system, and processes as defined by process calculi.
If a process requests something for which it must wait, it will be blocked. When the process is in the Blocked State, it is eligible for swapping to disk, but this is transparent in a virtual memory system, where blocks of memory values may be really on disk and not in main memory at any time. Note that even unused portions of active processes/tasks (executing programs) are eligible for swapping to disk. All parts of an executing program and its data do not have to be in physical memory for the associated process to be active.
Read more about this topic: Process (computing)
Famous quotes containing the words process, management, operating and/or systems:
“Because her instinct has told her, or because she has been reliably informed, the faded virgin knows that the supreme joys are not for her; she knows by a process of the intellect; but she can feel her deprivation no more than the young mother can feel the hardship of the virgin’s lot.”
—Arnold Bennett (1867–1931)
“This we take it is the grand characteristic of our age. By our skill in Mechanism, it has come to pass, that in the management of external things we excel all other ages; while in whatever respects the pure moral nature, in true dignity of soul and character, we are perhaps inferior to most civilised ages.”
—Thomas Carlyle (1795–1881)
“I love meetings with suits. I live for meetings with suits. I love them because I know they had a really boring week and I walk in there with my orange velvet leggings and drop popcorn in my cleavage and then fish it out and eat it. I like that. I know I’m entertaining them and I know that they know. Obviously, the best meetings are with suits that are intelligent, because then things are operating on a whole other level.”
—Madonna [Madonna Louise Ciccione] (b. 1959)
“The skylines lit up at dead of night, the air- conditioning systems cooling empty hotels in the desert and artificial light in the middle of the day all have something both demented and admirable about them. The mindless luxury of a rich civilization, and yet of a civilization perhaps as scared to see the lights go out as was the hunter in his primitive night.”
—Jean Baudrillard (b. 1929)