Definition of pre-emption in English English dictionary
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
a prior appropriation of something; "the preemption of bandwidth by commercial interests"
a judicial principle which states that certain federal laws apply over certain state laws
(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
A feature of the HUD Code which states that it may not be modified in any way by local or state building codes The HUD Code preempts all other building codes with regard to manufactured housing
In general, the doctrine that certain matters, either implicitly or by explicit expression of Congress, are of such a national, as opposed to local, character, that Federal laws supercede or take precedence over State laws ERISA has a very broad explicit preemption of any State law that "relates to" an employee benefit plan, whether or not the State law conflicts with ERISA (ERISA §514(a), 29 USC 1144(a))
The seizure, usually automatic, of military system facilities that are being used to serve a lower precedence call in order to serve immediately a higher precedence call (188)
The act of suspending the execution of one thread and starting (or resuming) another The suspended thread is said to have been "preempted" by the new thread In QNX, whenever a lower-priority thread is actively consuming the CPU, and a higher-priority thread becomes READY, the lower-priority thread is immediately preempted by the higher-priority thread
If a process becomes ready to execute and it has a higher priority than the currently executing process, the “new” process preempts the current process That is, the operating system saves the current process's context and switches to the context of the higher-priority process See also process state transition
U.S. policy that allowed the first settlers, or squatters, on public land to buy the land they had improved. Since improved land, coveted by speculators, was often priced too high for squatters to buy at auction, temporary preemptive laws allowed them to acquire it without bidding. The Pre-Emption Act (1841) gave squatters the right to buy 160 acres at $1.25 per acre before the land was auctioned. The Homestead Act (1862) made preemption an accepted part of U.S. land policy. See also Homestead Movement
the right to purchase something in advance of others the right of a government to seize or appropriate something (as property) the judicial principle asserting the supremacy of federal over state legislation on the same subject