(Emlak) A pre-emption right is a right to acquire certain property in preference to any other person. It usually refers to property newly coming into existence; a right to acquire existing property in preference to any other person is usually referred to as a right of first refusal
Involuntary switching of a CPU from one task to another User-space is pre-empted by interrupts, which can then either return to the process, or schedule another process (a process switch will also occur when the process "voluntarily" gives up the CPU by e g waiting for a disk block in kernel mode) Kernel mode tasks are never pre-empted (except by interrupts) - they are guaranteed use of the CPU until they sleep or yield the CPU Some kernel code runs with interrupts disabled, meaning nothing except an NMI can interrupt the execution of the code
A federal agency voiding a local ordinance or state law, asserting that the federal government, not the state or locality, has ultimate jurisdiction on the matter
interruption of execution of process or thread during time-sharing execution before its time-slice has expired in order to context switch to another process or thread which has been given execution priority over it