First-in first-out
<algorithm> (FIFO, or "queue") A data structure or hardware buffer from which items are taken out in the same order they were put in.
Also known as a "shelf" from the analogy with pushing items onto one end of a shelf so that they fall off the other.
A FIFO is useful for buffering a stream of data between a sender and receiver which are not synchronised - i.e. not sending and receiving at exactly the same rate. Obviously if the rates differ by too much in one direction for too long then the FIFO will become either full (
blocking the sender) or empty (
blocking the receiver).
A
Unix pipe is a common example of a FIFO.
A FIFO might be (but isn't ever?) called a LILO - last-in last-out.
The opposite of a FIFO is a LIFO (last-in first-out) or "
stack".
