TACL Reference Manual

Glossary
HP NonStop TACL Reference Manual—429513-018
Glossary-9
redefinition.
redefinition. A STRUCT declaration that gives a new definition, such as a different data
type or a different alignment, to an existing STRUCT or STRUCT item. All definitions
are valid concurrently, allowing a STRUCT or STRUCT item to be used in a variety of
ways.
reply. A response to a requester process by a server process. Contrast with request.
request. A message formatted and sent to a server by a requester. Requests also include
status messages such as CPU up and CPU down messages, which are placed on the
intended recipient’s process message queue ($RECEIVE file) by the operating system.
Contrast with reply.
requester. A process that initiates interprocess communication by sending a request to
another process. Contrast with server.
response. See reply.
retryable error. An error condition returned by the file system that can be corrected by
repeating the operation that caused the error. Sometimes operator intervention is
required before the retry; for example, to put paper into an empty printer. Contrast with
nonretryable error.
secondary extent. A contiguous area of disk storage allocated to a file. A file is made up of
one or more extents; the first extent is the primary extent, and other extents are
secondary extents. The secondary extents are all the same size for a specific file; the
primary extent can be a different size. See also primary extent.
segment. A unit of storage consisting of up to 64 pages of 1,024 words each.
segment file. As used by TACL, a file accessible by TACL that can contain TACL code and
data.
server. The process that receives, acts upon, and replies to messages from requesters.
Contrast with requester.
shared data segment. An extended data segment that can be accessed by more than one
process.
simple data item. A STRUCT item that contains a single value of a specific type.
slice. A portion of one or more logical processors and one part of a processor complex. A
slice consists of a chassis, processor board containing one or more processor
elements and memory, I/O interface board, midplane, optics adapters, fans, and power
supplies. Also called a processor slice. Also known as a blade element.
space-separated list. A list whose entries are separated from each other by a space.
Several built-in functions accept space-separated lists of values.