ACC Programmer's Reference Guide

126 Chapter3

ZCOM Tables and Data Structures

ZCOM Kernel Data

TheHP(PointertoZCOMsystemheader)structureisapointertoZCOM

subsystem header. It is set up by the LDM during ZCOM subsystem

startup. The ZCOM subsystem memory tables are accessed through this

pointer.

LINFO

The LINFO structure (Lock Information, struct z l info)containsthe

ZCOM locks used globally in the ZCOM subsystem. It is initialized by

the LDM during system bootup. The locks are used to provide exclusive

access to the sharable data structures in the ZCOM subsystem. The

fields are described in Table 3-51.

ZC_GLOCK -Globalspinlock

This is the highest lock order in the ZCOM subsystem. It protects the

ZCOM system header zheader_type in global memory (with some

exception, see ZC_RLOCK below), and the LDM static data such as the

interface request queue and ZCOM message log buffer.

ZC_MLOCK - Memory pool spinlock

This protects the ZCOM buffer pool. Used in buffer management

routines, such as buffer allocation and buffer freeing.

ZC_RLOCK -RemoteZLUspinlock

This lock protects the following ZCOM system header data fields. They

are connected with remote nodes or remote API processing:

hrdataq, hpntbl, hndpid, hndsig, hndmax, hnidle, hnhigh, hnlow, hnwait

Table 3-51 LINFO Structure Fields

Field Name Field Description Field Type Size

(Bytes)

ZC_GLOCK Global spinlock struct 16

ZC_MLOCK Memory spinlock struct 16

ZC_RLOCK Remote ZLU spinlock struct 16

ZC_SLOCK Super IFT spinlock struct 16