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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. |
RSHBK
Cross Reference (Contains links to field and bit definitions)
RSHBK Prolog
Name : HCPRSHBK
Description: RSPBK Header Block
DSECT : RSHBK
Function : Contains RSPBK chain header (there are three
RSPBK chains) and locks.
Located by : SYSPRTT field in SYSCM
SYSPUNT field in SYSCM
SYSRDRT field in SYSCM
Created by : HCPRIO
Deleted by : Never deleted
RSHBK Control Block Content
RSHBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure RSHBK RSPBK Header Block 0000 0 Signed 4 RSHCOUNT Count of number of RSPBKs 0004 4 Address 4 RSHANCH Pointer to first RSPBK Notes : There will be three versions of the RSHBK present on any system. One will represent the head of the reader RSPBKs, one will represent the head of the printer RSPBKs and one will represent the head of the punch RSPBKs. They will be anchored in SYSCM at SYSRDRT, SYSPRTT and SYSPUNT, respectively. No attempt should be made to acquire the lock represented by RSHLOCK while an RDEV lock is held. Furthermore, if more than one of these locks needs to be acquired, they should be acquired in the order of reader, printer and punch and released in the oppposite order to prevent possible dead-locks. These locks may be acquired by threads that are holding an RDEV lock. 0008 8 Dbl-Word 8 RSHLOCK (3) Lockwords used by HCPLCK to allow . us to manipulate RSPBK chains 0020 32 Signed 4 * Reserved for future IBM Use 0024 36 Signed 4 * Reserved for future IBM Use 00000028 RSHBKLEN *-RSHBK Length of RSHBK area
RSHBK Storage Layout
*** RSHBK - RSPBK Header Block * * +---------------------------+---------------------------+ * 0 | RSHCOUNT | RSHANCH | * +---------------------------+---------------------------+ * 8 | | * = RSHLOCK = * | | * +---------------------------+---------------------------+ * 20 |///////////////////////////|///////////////////////////| * +---------------------------+---------------------------+ * 28 * *** RSHBK - RSPBK Header Block
RSHBK Cross Reference
(contains links to field and bit definitions)Symbol Dspl Value -------------- ---- -----RSHANCH 0004
RSHBKLEN 0024 00000028
RSHCOUNT 0000
RSHLOCK 0008
Last updated on 3 Aug 1999 at 12:28:24 EDT.
Copyright IBM Corporation, 1990, 1999