LATBK Back to Index page
 
Prolog 
Control Block Contents 
   LATBK 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.


  LATBK Prolog Top of page
 
 NAME       : HCPLATBK
 DESCRIPTION: C System Services Latch block
 DSECT      : LATBK
 FUNCTION   : C System Services Latch block used to describe the
              suspend lock used by platform specific C Services
 LOCATED BY : Passed as argument on latch, unlatch, testLatch
              and eventWait services
 CREATED BY : allocateLatch service
 DELETED BY : deallocateLatch service
 SERIALIZED : None
 RELOCATION CONSIDERATIONS : None
 NOTES      : This COPY file is modeled after HCPLKWRD so
              existing CP lock routines could be utilized.
 
 
  LATBK Control Block Content Top of page
 

 LATBK DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure LATBK C System Services Latch block 0000 0 Dbl-Word 8 LATCSWAP (0) Doubleword updated by Compare and Swap 0000 0 Signed 4 LATSTATE Current lock state. 0004 4 Address 4 LATQUEUE Pointer to chain of deferred CPEBK's 0008 8 Signed 8 LATQQTOD TOD saved at last enqueue/dequeue. (Only stamped if there's a queue.) 0010 16 Bitstring 1 LATFLG1 Miscellaneous lock flags (not used in C code - for CP compatibility) 0011 17 Bitstring 3 LATDQLEN Current length of defer queue. 0014 20 Signed 4 LATDYTOD TOD saved at start of last "delay" 0018 24 Address 8 LATTHRED Pointer to thread which holds latch 00000020 LATBSIZE *-LATBK size in bytes 00000004 LATSIZE (*-LATBK+7)/8 size in double words
 
 
  LATBK Storage Layout Top of page
 
          
*** LATBK - C System Services Latch block
*
*     +---------------------------+---------------------------+
*   0 |         LATSTATE          |         LATQUEUE          |
*     +---------------------------+---------------------------+
*   8 |                       LATQQTOD                        |
*     +------+--------------------+---------------------------+
*  10 |:FLG1 |     LATDQLEN       |         LATDYTOD          |
*     +------+--------------------+---------------------------+
*  18 |                       LATTHRED                        |
*     +-------------------------------------------------------+
*  20
*
*** LATBK - C System Services Latch block
 
 
  LATBK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
LATBSIZE       0018 00000020
LATCSWAP       0000
LATDQLEN       0011
LATDYTOD       0014
LATFLG1        0010
LATQQTOD       0008
LATQUEUE       0004
LATSIZE        0018 00000004
LATSTATE       0000
LATTHRED       0018
 
This information is based on z/VM 7.3.0 Last updated on 22 Jun 2022 at 15:51:55 EDT.
Copyright IBM Corporation, 1990, 2022