ZCOM Tables and Data Structures

Queue Header

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

 

 

 

 

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

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Chapter 3

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HP Advanced Communications Controllers (ACC) manual Queue Header Structure zqhdtype, Qlimit, Qfdata, Qfunc