Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM. |
ACABK
Control Block Contents
ACABK DSECT
Cross Reference (Contains links to field and bit definitions)
ACABK Prolog
Name : HCPVEXBK Description: Map CASBKs at beginning of VEXBK. DSECT : ACABK Notes : The following maps the area at the beginning of the VEXBK which contains the CASBKs. Hence, this DSECT is called the ACABK (Area for Contiguous Available Slots). The ACABK is used to avoid checking for page or spool slots numerous times.
ACABK Control Block Content
ACABK DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure ACABK Map CASBKs at beginning of VEXBK. 0000 0 Signed 4 ACACAS (16) Contains 16 CASBKS used by slot allocation. 0040 64 Signed 4 ACACURSL Current slot number in EXTBK (start search for new CASBK here) 0044 68 Signed 4 ACALSTSL Last slot in current cylinder 0048 72 Signed 4 ACACURCY Current cylinder in EXTBK 004C 76 Signed 4 ACAEXTBK Pointer to current EXTBK 0050 80 Bitstring 1 ACAFIRST Index into ACABK of first CASBK 0051 81 Bitstring 1 ACALAST Index into ACABK of last CASBK 0052 82 Bitstring 1 ACAFLAG Flags 1... .... ACAREDO X'80' Slots were allocated by a method other than slot alloc. (PGC or PGTDA) Redo CASBKs before slot allocation. .1.. .... ACAANYRP X'40' No minimum size when searching for a replacement CASBK. (space is fragmented) ..1. .... ACAANYAL X'20' Take any size CASBK when searching for a block for allocation. (this is set temporarily for large block requests) ...1 .... ACAINIT X'10' CASBKs have been initialized 0053 83 Bitstring 1 * (5) Reserved for IBM use 00000058 ACASIZE *-ACABK Size of area for CASBKs.
ACABK Storage Layout
*** ACABK - Map CASBKs at beginning of VEXBK. * * +-------------------------------------------------------+ * 0 | | * = ACACAS = * | | * +---------------------------+---------------------------+ * 40 | ACACURSL | ACALSTSL | * +---------------------------+---------------------------+ * 48 | ACACURCY | ACAEXTBK | * +------+------+------+------+---------------------------+ * 50 |:FIRST|:LAST |:FLAG |//////////////////////////////////| * +------+------+------+----------------------------------+ * 58 * *** ACABK - Map CASBKs at beginning of VEXBK.
ACABK Cross Reference
Symbol Dspl Value -------------- ---- ----- ACAANYAL 0052 20 ACAANYRP 0052 40 ACACAS 0000 ACACURCY 0048 ACACURSL 0040 ACAEXTBK 004C ACAFIRST 0050 ACAFLAG 0052 ACAINIT 0052 10 ACALAST 0051 ACALSTSL 0044 ACAREDO 0052 80 ACASIZE 0053 00000058
Last updated on 5 Jun 2001 at 17:10:55 EDT.
Copyright IBM Corporation, 1990, 2001