Nonpreemptive multitasking
Encyclopedia
Nonpreemptive multitasking is a style of computer multitasking
in which the operating system never initiates a context switch
from a running process
to another process. Such systems are either statically scheduled
, most often periodic systems, or exhibit some form of cooperative multitasking, in which case the computational tasks can self-interrupt and voluntarily give control to other tasks.
When non preemptive is used, a process that receives such resources can not be interrupted until it is finished.
Cooperative multitasking is a type of multitasking in which the process currently controlling the CPU must offer control to other processes. It is called “cooperative” because all programs must cooperate for it to work. In contrast, preemptive multitasking interrupts applications and gives control to other processes outside of an application's control.
Computer multitasking
In computing, multitasking is a method where multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for...
in which the operating system never initiates a context switch
Context switch
A context switch is the computing process of storing and restoring the state of a CPU so that execution can be resumed from the same point at a later time. This enables multiple processes to share a single CPU. The context switch is an essential feature of a multitasking operating system...
from a running process
Process (computing)
In computing, a process is an instance of a computer program that is being executed. It contains the program code and its current activity. Depending on the operating system , a process may be made up of multiple threads of execution that execute instructions concurrently.A computer program is a...
to another process. Such systems are either statically scheduled
Scheduling (computing)
In computer science, a scheduling is the method by which threads, processes or data flows are given access to system resources . This is usually done to load balance a system effectively or achieve a target quality of service...
, most often periodic systems, or exhibit some form of cooperative multitasking, in which case the computational tasks can self-interrupt and voluntarily give control to other tasks.
When non preemptive is used, a process that receives such resources can not be interrupted until it is finished.
Cooperative multitasking is a type of multitasking in which the process currently controlling the CPU must offer control to other processes. It is called “cooperative” because all programs must cooperate for it to work. In contrast, preemptive multitasking interrupts applications and gives control to other processes outside of an application's control.
See also
- SchedulingScheduling (computing)In computer science, a scheduling is the method by which threads, processes or data flows are given access to system resources . This is usually done to load balance a system effectively or achieve a target quality of service...
- PreemptionPreemption (computing)In computing, preemption is the act of temporarily interrupting a task being carried out by a computer system, without requiring its cooperation, and with the intention of resuming the task at a later time. Such a change is known as a context switch...