[1] : The Free On-line Dictionary of Computing (27 SEP 03)

pre-emptive multitasking
     
         a type of multitasking where
        the scheduler can interrupt and suspend "swap out" the
        currently running task in order to start or continue running
        "swap in" another task.  the tasks under pre-emptive
        multitasking can be written as though they were the only task
        and the scheduler decides when to swap them.  the scheduler
        must ensure that when swapping tasks, sufficient state is
        saved and restored that tasks do not interfere.
     
        the length of time for which a process runs is known as its
        "time slice" and may depend on the task's priority or its
        use of resources such as memory and i/o.
     
        os/2, unix and the amiga use pre-emptive multitasking.
     
        this contrasts with cooperative multitasking where each task
        must include calls to allow it to be descheduled
        periodically.
     
        1995-03-20
     
     
see also:
multitasking scheduler time slice os/2 unix amiga 
cooperative multitasking deschedule 

Pre-Emptive >> P Words
Pre-Emptive, definition of term: Pre-Emptive
pre-emptive_pag1.html

Multitasking >> M Words
Multitasking, definition of term: Multitasking
multitasking_pag1.html