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Programming Interface Information:
This information is NOT intended to be used as Programming Interfaces of z/VM. |
FORBK
Control Block Contents
FORBK DSECT
FORCTBL DSECT
Cross Reference (Contains links to field and bit definitions)
FORBK Prolog
NAME : HCPFORBK
DESCRIPTION: The FOR control block.
DSECT : FORBK
FUNCTION : Provides a mapping of the FORBK control block containing
the *ASYNCMD connection table for a virtual configuration.
LOCATED BY : The VMDFORBK field in the base VMDBK points to the FORBK
CREATED BY : Entry point HCPASYCN will create the FORBK on the first connection
to the *ASYNCMD system service.
DELETED BY : The following entry points:
HCPFORSP - End of FOR command handler
HCPFORRT - Reset handler
REFERENCES : FORCTBL - mapping of a single *ASYNCMD connection table entry
SERIALIZED : When accessing the FORBK, the lock hierarchy is
as follows: first obtain the IUCV lock, then
get the FOR lock.
NOTES : None
FORBK Control Block Content
FORBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure FORBK The FOR control block. 0000 0 Dbl-Word 8 FORLOCK (3) FOR Lock 0018 24 Bitstring 1 FORFLAG Flag byte 1... .... FORORPHN X'80' This FORBK is orphaned .1.. .... FORALLSP X'40' All slots in use are sever-pending 0019 25 Bitstring 1 * Reserved for future IBM use 001A 26 Signed 2 FORNXFRE The next available slot number in the *ASYNCMD connection table. Slots are numbered 0-7, if the FORNXFRE is 8, then the table is full. 001C 28 Signed 2 FORMRCON The most recently connected slot number in the *ASYNCMD connection table that is not sever-pending 001E 30 Signed 2 * Reserved for future IBM use 0020 32 Bitstring 8 FORTBL (2) *ASYNCMD connection table 0000000C FORSIZE (*-FORBK+7)/8 Size of FORBK in double words 00000060 FORBSIZE FORSIZE*8 Size of FORBK in bytes 00000008 FORECNT 8 Number of entries in the *ASYNCMD connection table
FORCTBL DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure FORCTBL The FOR control block. 0000 0 Signed 2 FORCUPTH User side path ID 0002 2 Signed 2 FORCAPTH *ASYNCMD side path ID 0004 4 Signed 2 FORCUCTR Count of outstanding FOR commands 0006 6 Bitstring 1 FORCFLAG Flag byte 1... .... FORCSEVP X'80' Path is sever-pending 0007 7 Bitstring 1 * Reserved for future IBM use 00000001 FORCSIZE (*-FORCTBL+7)/8 Size in FORCTBL in double words 00000008 FORCSIZB FORCSIZE*8 Size in FORCTBL in bytes
FORBK Storage Layout
*** FORBK - The FOR control block. * * +-------------------------------------------------------+ * 0 | | * = FORLOCK = * | | * +------+------+-------------+-------------+-------------+ * 18 |:FLAG |//////| FORNXFRE | FORMRCON |/////////////| * +------+------+-------------+-------------+-------------+ * 20 | FORTBL | * | | * +-------------------------------------------------------+ * 30 * *** FORBK - The FOR control block. *** FORCTBL - The FOR control block. * * +-------------+-------------+-------------+------+------+ * 0 | FORCUPTH | FORCAPTH | FORCUCTR |:CFLAG|//////| * +-------------+-------------+-------------+------+------+ * 8 * *** FORCTBL - The FOR control block.
FORBK Cross Reference
Symbol Dspl Value -------------- ---- ----- FORALLSP 0018 40 FORBSIZE 0020 00000060 FORCAPTH 0002 FORCFLAG 0006 FORCSEVP 0006 80 FORCSIZB 0007 00000008 FORCSIZE 0007 00000001 FORCUCTR 0004 FORCUPTH 0000 FORECNT 0020 00000008 FORFLAG 0018 FORLOCK 0000 FORMRCON 001C FORNXFRE 001A FORORPHN 0018 80 FORSIZE 0020 0000000C FORTBL 0020
This information is based on z/VM V5R2.0. Last updated on 24 Mar 2006 at 07:06:31 EDT.
Copyright IBM Corporation, 1990, 2005