6760 ServerNet/DA Manual

Glossary
6760 ServerNet/DA Manual—424879-003
Glossary-84
set-user-ID program
set-user-ID program. In the Open System Services (OSS) environment, a program file that
has the
S_ISUID bit set in its file mode.
shared memory. An interprocess communication mechanism that allows two or more
processes to share a given region of memory.
shared run-time library (SRL). An object file that the operating system links to a program
file at run time. SRLs use direct addressing and can load and execute only at a specific
assigned virtual memory address (the same address in all processes). TNS processes
and TNS/R processes use different forms of SRLs.
shell. In the Open System Services (OSS) environment, a program that interprets
sequences of text input as commands. A shell can operate on an input stream, or it
can interactively prompt and read commands from a terminal.
shielded twisted pair (STP). A transmission medium consisting of two twisted conductors
with a foil or braid shield. Contrast with unshielded twisted pair (UTP)
.
shutdown file. A file invoked by the local operator or by another shutdown file that contains
commands to shut down system devices, communications lines, and system and
application software. Contrast with startup file
.
SID. See system image disk (SID) or source ServerNet ID (SID).
signal. The method by which an environment notifies a process of an event. Signals are
used to notify a process when an error that is not related to input or output has
occurred. See also Open System Services (OSS) signal
.
signal delivery. The time when Open System Services (OSS) takes the action appropriate
for a specific process and a specific signal.
signal generation. The time when an event occurs that causes a signal for a process.
signal handler. A function or procedure that is executed when a specific signal is delivered
to a specific process.
Signaling System Number 7 (SS7). The protocol used in public networks to establish
connections between switches.
signal mask. The set of signals that are currently blocked from delivery to a specific
process.
signal reference grid. A series of conductors, constructed of pure or composite metals (for
example, copper) with good surface conductivity. A superior signal reference grid is
installed on the subfloor of a computer room and connected to the raised-floor
structure to establish constant and equal potential for all equipment in the computer
room that is connected to it.