RSHBK Back to Index page
 
Prolog 
Control Block Contents 
   RSHBK DSECT
Storage Layout 
Cross Reference (Contains links to field and bit definitions)
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.


  RSHBK Prolog Top of page
 
 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 Top of page
 

 RSHBK DSECT Top of page
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 Top of page
 
          
*** RSHBK - RSPBK Header Block
*
*     +---------------------------+---------------------------+
*   0 |         RSHCOUNT          |         RSHANCH           |
*     +---------------------------+---------------------------+
*   8 |                                                       |
*     =                       RSHLOCK                         =
*     |                                                       |
*     +---------------------------+---------------------------+
*  20 |///////////////////////////|///////////////////////////|
*     +---------------------------+---------------------------+
*  28
*
*** RSHBK - RSPBK Header Block
 
 
  RSHBK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
RSHANCH        0004
RSHBKLEN       0024 00000028
RSHCOUNT       0000
RSHLOCK        0008
 
This information is based on z/VM 7.3.0 Last updated on 22 Jun 2022 at 15:54:30 EDT.
Copyright IBM Corporation, 1990, 2022