HP UX 11i v1 I/O Cards manual Zcglock, Zcmlock, Zcrlock, Zcslock

ZCOM Tables and Data Structures

ZCOM Kernel Data

HP

The HP (Pointer to ZCOM system header) structure is a pointer to ZCOM 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 zlinfo) contains the 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.

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

ZC_GLOCK - Global spinlock

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 - Remote ZLU spinlock

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

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