JargonFile/entries/atomic.txt

atomic

adj. [from Gk. atomos , indivisible] 1. Indivisible; cannot be split up. For
example, an instruction may be said to do several things atomically , i.e.,
all the things are done immediately, and there is no chance of the
instruction being half-completed or of another being interspersed. Used esp.
to convey that an operation cannot be screwed up by interrupts. This routine
locks the file and increments the file's semaphore atomically. 2. [primarily
techspeak] Guaranteed to complete successfully or not at all, usu. refers to
database transactions. If an error prevents a partially-performed
transaction from proceeding to completion, it must be backed out , as the
database must not be left in an inconsistent state. Computer usage, in
either of the above senses, has none of the connotations that atomic has in
mainstream English (i.e. of particles of matter, nuclear explosions etc.).