Guardian Programmer's Guide

Table Of Contents
Glossary
Guardian Programmer’s Guide 421922-014
Glossary - 5
completion code
completion code. A value used to return information about a process to its ancestor
process when the process is deleted. This value is returned in the Process deletion
message, system message -101.
complex instruction-set computing (CISC). A CPU architecture based on a large
instruction set, characterized by numerous addressing modes, multicycle machine
instructions, and many special-purpose instructions. Contrast with reduced instruction-
set computing (RISC).
concurrency control. The use of locking mechanisms to prevent data corruption due to
concurrent access.
condition code. A status returned in the Environment Register by some file-system
procedure calls to indicate whether the call was successful. A condition-code-greater-
than (CCG) indicates a warning, a condition-code-less-than (CCL) indicates an error,
and a condition-code-equal (=) indicates successful execution.
context-free server. A server process that does not retain any information about previous
processing. It knows only about the processing of the current request message.
conversational mode. A mode of communication between a terminal and its I/O process in
which each byte is transferred from the terminal to the CPU I/O buffer as it is typed.
Each data-transfer operation finishes when a line-termination character is typed at the
terminal. Contrast with page mode.
CPU. A functional unit of a NonStop server that is composed of one or more instruction
processing units (IPUs) and memory. Each CPU has its own copy of the NonStop
operating system.
cpu, pin. In the Guardian environment, a number pair that uniquely identifies a process
during the lifetime of the process, consisting of the CPU number and the process
identification number (PIN).
creator. The process that causes a process to be built from a program file of another
pr
ocess. Compare with
mom and ancestor.
creator access ID (CAID). A process attribute that identifies, by user ID, the user who
initiated the process creation. Contrast with process access ID (PAID).
current selectable segment. The selectable segment that can be accessed by a process.
A process specifies the current selectable segment by calling the USESEGMENT or
SEGMENT_USE_ procedure to select one of a set of alternative selectable segments.
D-series system. A system that is running a D00 or later version of the operating system.
data segment. A virtual memory segment holding data. Every process begins with its own
data segments for program global variables and runtime stacks (and for some libraries,
instance data). Additional data segments can be dynamically created. See also flat
segment and selectable segment.