Programming Interface Information: This information is NOT intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only.

IDSBK

Prolog  

Control Block Contents  

IDSBK DSECT

IDSEGENT DSECT

IDSLTENT DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

IDSBK Prolog

 NAME       : HCPIDSBK
 DESCRIPTION: ISFC ID segment table
 DSECT      : IDSBK
 FUNCTION   : A simple segment-page table to locate address of a
              PTHBK or generate a unique ID for an ISFC resource.
 LOCATED BY : HCPBTB    contains an anchor for each table.
 CREATED BY : HCPBTB    as new entries are needed.
 DELETED BY : HCPBTB    as old entries are discarded.
 SERIALIZED : The ISFC global lock (HCPBDSGL).

 

IDSBK Control Block Content


IDSBK DSECT

Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IDSBK ISFC ID segment table 0000 0 Signed 4 IDSCOUNT Total count of IDs in this table 0004 4 Signed 4 IDSHMARK High water mark for this table 0008 8 Dbl-Word 8 * Reserved The value of (IDSMAXSG*IDSEGBLN) for BLOCKMAP is 64*8 = 512 0010 16 Bitstring 0 IDSSTART Reserve IDSEGENT space 00000042 IDSSIZE (*-IDSBK+7)/8 Size of IDSBK in doublewords FUNCTION : This is the format for a single 'Segment Entry' in the IDSBK. LOCATED BY : IDSSTART contains IDSEGENT entries.

IDSEGENT DSECT

Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IDSEGENT ISFC ID segment table 0000 0 Signed 4 IDSEGCNT Count of IDs in this segment 0004 4 Address 4 IDSEGADD Address of segment page 00000008 IDSEGBLN *-IDSEGENT Length of segment entry in bytes FUNCTION : This is the format for a single 'Slot Entry' in the IDSBK. LOCATED BY : IDSSTART contains IDSLTENT entries.

IDSLTENT DSECT

Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure IDSLTENT ISFC ID segment table 0000 0 Address 4 IDSLTADD Address of slot entry 0=>available 1=>allocated, not a pointer >1=>allocated, pointer to entry 00000004 IDSLTBLN *-IDSLTENT Length of slot entry in bytes IUCV is limited to 64K paths, so each of these tables can only have 64K entries. Each "slot" in a segment consists of a fullword, so each segment (4K page) can hold 1K slots. Therefore, the maximum number of segment entries per table is 64 and the maximum number of slots per segment is 1024. 00000040 IDSMAXSG 64 Maximum segment entries per table 00000400 IDSMAXSL 1024 Maximum slots per segment 00000001 IDSLTFUL 1 Zero implies slot available Non-zero implies slot allocated

 

IDSBK Storage Layout

*** IDSBK - ISFC ID segment table
*
*     +---------------------------+---------------------------+
*   0 |         IDSCOUNT          |         IDSHMARK          |
*     +---------------------------+---------------------------+
*   8 |///////////////////////////////////////////////////////|
*     +-------------------------------------------------------+
*  10 |                                                       |
*     =                       IDSSTART                        =
*     |                                                       |
*     +-------------------------------------------------------+
*
*** IDSBK - ISFC ID segment table
*** IDSEGENT - ISFC ID segment table
*
*     +---------------------------+---------------------------+
*   0 |         IDSEGCNT          |         IDSEGADD          |
*     +---------------------------+---------------------------+
*   8
*
*** IDSEGENT - ISFC ID segment table
*** IDSLTENT - ISFC ID segment table
*
*     +---------------------------+
*   0 |         IDSLTADD          | 4
*     +---------------------------+
*
*** IDSLTENT - ISFC ID segment table

 

IDSBK Cross Reference

(contains links to field and bit definitions)
Symbol         Dspl Value
-------------- ---- -----

IDSCOUNT 0000

IDSEGADD 0004

IDSEGBLN 0004 00000008

IDSEGCNT 0000

IDSHMARK 0004

IDSLTADD 0000

IDSLTBLN 0000 00000004

IDSLTFUL 0000 00000001

IDSMAXSG 0000 00000040

IDSMAXSL 0000 00000400

IDSSIZE 0010 00000042

IDSSTART 0010


This information is based on VM/ESA 2.4.0.
Last updated on 3 Aug 1999 at 12:05:26 EDT.
Copyright IBM Corporation, 1990, 1999