Programming Interface Information:
This information is NOT intended to be used as Programming Interfaces of z/VM. |
SHRBK
Control Block Contents
SHRBK DSECT
Cross Reference (Contains links to field and bit definitions)
SHRBK Prolog
NAME : HCPSHRBK DESCRIPTION: SHARE BLOCK DSECT : SHRBK FUNCTION : This block is used to keep track of each NSS or DCSS that a user is attached to. LOCATED BY : All SHRBKs for the NSS and/or DCSSs that the virtual machine user is accessing are chained together in a list anchored off the VMDBK. VMDSHRPT is the pointer to the first SHRBK for this user. A zero pointer indicates that the user's chain is empty. SHRFWDPT is the pointer to the next SHRBK in the user's chain. The chain end is indicated when SHRFWDPT is zero. - All SHRBKs for users using a specific SNTBK are chained together in a doubly linked list anchored off the SNTBK. This list represents all users who have loaded the NSS or DCSS. SNTSHRPT is the pointer to the first SHRBK in the chain for this SNTBK. A zero pointer indicates that the chain is empty. SHRQUEFW is the pointer to the next SHRBK in the chain for this SNTBK. The chain end is indicated when SHRQUEFW is zero. SHRQUEBK is the pointer to the previous SHRBK in the chain for this SNTBK. CREATED BY : HCPNSL when loading an NSS or DCSS. DELETED BY : HCPNSP - when the user purges the DCSS. HCPNSP - when the user IPLs a system, all SHRBKs for that user are purged. COMMENTS : None.
SHRBK Control Block Content
SHRBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure SHRBK SHARE BLOCK 0000 0 Address 4 SHRFWDPT Forward pointer to this user's next SHRBK. 0004 4 Address 4 SHRSNTPT Pointer to the SNTBK for this NSS or DCSS. 0008 8 Character 8 SHRNAME The name for this NSS or DCSS. 0010 16 Signed 4 SHRFLAGS (0) Flags for SHRBK. 0010 16 Bitstring 1 SHRTYPE Type information byte. .... ...1 SHREXCL X'01' This bit indicates that the NSS or DCSS is an exclusive copy. 0011 17 Bitstring 1 * (3) Reserved for IBM use. 0014 20 Address 4 SHRVMDBK @ of VMDBK that owns this SHRBK. 0018 24 Address 4 SHRQUEFW Next SHRBK on a chain of SHRBKs associated with a specific SNTBK. 001C 28 Address 4 SHRQUEBK Prev.SHRBK on a chain of SHRBKs associated with a specific SNTBK. 0020 32 Address 4 SHRLSSA Address of the SNTBK defining the segment space through which the named member segment was loaded. When this field is equal to SHRSNTPT, SHRNAME is not a member segment. It is a named saved segment or segment space. 0024 36 Signed 4 * Reserved for IBM use 00000005 SHRSIZE ((*-SHRBK+7)/8) Block in double words.
SHRBK Storage Layout
*** SHRBK - SHARE BLOCK * * +---------------------------+---------------------------+ * 0 | SHRFWDPT | SHRSNTPT | * +---------------------------+---------------------------+ * 8 | SHRNAME | * +------+--------------------+---------------------------+ * 10 |:TYPE |////////////////////| SHRVMDBK | * +------+--------------------+---------------------------+ * 18 | SHRQUEFW | SHRQUEBK | * +---------------------------+---------------------------+ * 20 | SHRLSSA |///////////////////////////| * +---------------------------+---------------------------+ * 28 * *** SHRBK - SHARE BLOCK
SHRBK Cross Reference
Symbol Dspl Value -------------- ---- ----- SHREXCL 0010 01 SHRFLAGS 0010 SHRFWDPT 0000 SHRLSSA 0020 SHRNAME 0008 SHRQUEBK 001C SHRQUEFW 0018 SHRSIZE 0024 00000005 SHRSNTPT 0004 SHRTYPE 0010 SHRVMDBK 0014
Copyright IBM Corporation, 1990, 2001