ACC Programmer's Reference Guide

ZCOM Tables and Data Structures
Queue Header
Chapter 3102
QNMSG - Number on queue
Counter of the number of messages on the queue. When this is zero the
queue is empty.
QALLOC - Number of allocated messages
This field is used in the free queue header to keep track of the number of
buffer segments allocated for ZCOM subsystem use. A value of zero
means that no buffers have been allocated for use by the ZCOM
subsystem. A large value indicates heavy usage of the buffer pool.
QLIMIT - Queue limit
The maximum number of messages or bytes that may be linked to this
queue. If the ZCOM_QFLAG_BLT bit in qflag is not set, this field is a
limit on the number of messages. Otherwise, this value is a limit on the
number of bytes that can be linked to this queue. The default queue limit
Table 3-28 Queue Header Structure (zqhd_type)
Field Name Field Description Field Type
Size
(Bytes)
QNMSG Number of messages on queue uns.int 4
QLIMIT Max messages/bytes allowed on queue uns.int 4
QHEAD Pointer to first message on queue pointer 8
QTAIL Pointer to last message on queue pointer 8
QMMAX Historical max number of messages uns.int 4
QTMSG Total messages through queue uns.int 4
QBYTES Number of bytes on queue uns.int 4
QWAITER Number of waiters on this queue uns.short 2
QFLAG Queue flags uns.short 2
QFDATA Queue function data uns.int 4
SPARE1 Reserved, not used int 4
QFUNC Queue function pointer 8