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Prolog 
Control Block Contents 
   DCHBK 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.


  DCHBK Prolog Top of page
  
 NAME       : HCPDCHBK
 DESCRIPTION: Diagnose Control Header
 DSECT      : DCHBK
 FUNCTION   : The Diagnose Control Header serializes use of the
              diagnose control block locator array, as well as
              locates the diagnose control block locator array.
 LOCATED BY : SYSCM.SYSDCHBK
 CREATED BY : HCPHVAIN
 DELETED BY : None.
 REFERENCES : None.
 SERIALIZED : The DCHBK is created during system initialization;
              no further serialization is required.
              The DCHLOCK is obtained exclusive in order to
              serialize additions to the array of addresses of
              DGNBKs.  Since an address in the array is never
              deleted, there is no conflict between searching and
              adding.  Therefore, there is no need to obtain the
              DCHLOCK for searching.
 RELOCATION CONSIDERATIONS : None
 
 
  DCHBK Control Block Content Top of page
  




 DCHBK DSECT
Top of page


Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      DCHBK          Diagnose Control Header
0000    0 Dbl-Word     8 DCHLOCK (3)    Lock for serializing actions on
                                        the DCHDGNIX array of addresses.
0018   24 Address      4 DCHDGNIX       Address of the array of addresses
                                        of DGNBKs.
001C   28 Address      4 *              Reserved
0020   32 Dbl-Word     8 DCH$END (0)    The end
 
 
  DCHBK Storage Layout Top of page
  
          
*** DCHBK - Diagnose Control Header
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       DCHLOCK                         =
*     |                                                       |
*     +---------------------------+---------------------------+
*  18 |         DCHDGNIX          |///////////////////////////|
*     +---------------------------+---------------------------+
*
*** DCHBK - Diagnose Control Header
 
 
  DCHBK Cross Reference Top of page
  
 
Symbol         Dspl Value
-------------- ---- -----
DCH$END        0020
DCHDGNIX       0018
DCHLOCK        0000
 
This information is based on z/VM 7.3.0 Last updated on 22 Jun 2022 at 15:48:50 EDT.
Copyright IBM Corporation, 1990, 2022