Reference Guide

ZCOM Tables and Data Structures
ZLU Tables
Chapter 3 59
ZLU Tables
The ZCOM logical unit table relates a terminal device or a program
queue with a number or logical unit. The ZCOM logical units are called
ZLUs to distinguish them from the HP-UX logical units (LUs).
Each ZLU entry structure contains 40 bytes of data.
The ZLU table is split into two logically distinct parts. The first part is
the physical terminal area, and the second the dynamically assignable
program ZLUs. The latter are used for program input queues. The ZLUs
can be mapped so that a particular ZLU can point to any other ZLU.
Individual ZLU Entries
The individual ZLU data structure (zlu_type) layout is shown in
Table 3-7.
Table 3-7 Individual ZLU Data Structure (zlu_type)
Field Name Field Description Field Type
Size
(Bytes)
zcksum ZLU checksum uns.short 2
zlttype ZLU type uns.short 2
zpoint ZLU pointer or mapped node nmbr uns.short 2
zmpzlu Mapped ZLU number uns.short 2
zmpzcs Mapped ZLU checksum uns.short 2
zlname ZLU Name (8 bytes) char [8] 8
zowner PID number of owner uns.short 2
ztimer Timeout interval (seconds) short 2
zclock Timeout clock short 2
zlock ZLU lock pointer pointer 8
refcnt Lock reference count unns.int 4