Reference Guide

ZCOM C I/F Library Routines
ZLTQUEUE (3X)
Chapter 4 249
PAR AMETER S
NOTES The data queue returned should only be used for terminals within the
specified application group (there is NO queue ownership validation
when it is used in ltqdget and ltqdput). An application value of zero
means terminals in ALL application groups. This zero application value
allows the queue to be used to store global data for all terminals in the
system.
Routine zltqueue returns an already assigned queue if the queue label
matches a previously assigned queue (in this case the specified
application number is not used or validated). This provides a facility to
share a data queue between different programs and enables program
restartability.
The following example illustrates the queue allocation algorithm:
appln Application number of terminal group.
label Queue label name.
queuep
(Return
Param)
Data queue number (or ZCOM error, if negative)
Appln
Progra
m
Appl
n
Nmb
r
Appln
Label
Queue
Queue
No.
Returned
A30USAGE
1
1 <-- first allocation
B 0 GLOBA
L
2 <-- global allocation
C 40 CCCCC
C
1 <-- different appln group
D30USAGE
2
3 <-- same appln, diff usage
E30USAGE
1
1 <-- data queue sharing