pre-emptive multitasking

1 definition found

pre-emptive multitasking - Free On-line Dictionary of Computing (26 May 2007) :

  pre-emptive multitasking
  
     <operating system, parallel> 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)