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Prolog 
Control Block Contents 
   NSUBK 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.


  NSUBK Prolog Top of page
 
 NAME       : HCPNSUBK
 DESCRIPTION: Auxillary Storage Management utility data
 DSECT      : NSUBK
 FUNCTION   : This block will map the ASM data module HCPNSUDA.
 LOCATED BY : This block is located in HCPNSUDA.
 RELOCATION CONSIDERATIONS : None
 NOTES      :
                  Data Queue Definitions
                  ----------------------
  Saved Segment SNTBK queue: The Saved Segment SNTBK queue is
  a list of SNTBKs that represents each DCSS and Segment Space
  that is currently loaded by at least one user. Its header
  is NSUSGQAN.
  Named Saved System SNTBK queue: The Named Saved System SNTBK
  queue is a list of SNTBKs that represents each Named Saved
  System that is IPL'd by at least one user. Its header is
  NSUSYQAN.
  *NSS SDF queue: The *NSS SDF queue is a list of all Saved
  Segment and Named Saved System SDF files. Whenever a Saved
  Segment or Named Saved System is defined a spool file is
  created and put onto this queue. When the first DIAG X'64'
  Load or CP IPL command is processed for the Saved Segment
  or Named Saved System, the SDF file is opened, the SNTBK
  description page is read into storage and put onto the
  Saved Segment SNTBK or Named Saved System SNTBK queue
  respectively. If the Saved Segment is a member segment then
  the Segment Space SNTBK will be put onto the Saved Segment
  SNTBK queue. The SDF file remains open for read as long as
  at least one user has the Saved Segment loaded or the Named
  Saved System IPLed. The header of the *NSS SDF queue is
  located in the FILID table (reserved entry *NSS).
  VMDBK/SHRBK queue: The VMDBK/SHRBK is a queue of SHRBKs
  that represents a DIAG X'64' Load or CP IPL command for
  the owner of the VMDBK. Each time a Saved Segment or Named
  Saved System is loaded a SHRBK is added to this queue. It
  is removed by a DIAG X'64' Purge request or a system reset.
  The header of the VMDBK/SHRBK is VMDSHRPT.
  SNTBK/SHRBK queue: The SNTBK/SHRBK is a queue of SHRBKs that
  represents a DIAG X'64' Load or CP IPL command for this
  Saved Segment or Named Saved System. Each time a Saved
  Segment or Named Saved System is loaded a SHRBK is added to
  this queue. It is removed by a DIAG X'64' Purge request or
  a system reset. The header of the SNTBK/SHRBK is SNTSHRPT.
  SAVESEG SNTBK queue: The SAVESEG SNTBK queue is a list of
  SNTBKs that represents each Saved Segment that is currently
  being saved. This queue should be referenced by any CP
  function (such as Query or Purge NSS) that needs to obtain
  information about a Saved Segment that is currently being
  saved. The header of the SAVESEG queue is NSUSSGAN.
  SAVESYS SNTBK queue: The SAVESYS SNTBK queue is a list of
  SNTBKs that represents each Named Saved System that is
  currently being saved. This queue should be referenced by
  any CP function (such as Query or Purge NSS) that needs to
  obtain information about a Named Saved System that is
  currently being saved. The header of the SAVESYS queue is
  NSUSSYAN.
  Lock Hierarchy for Saved Segment or Named Saved System
  ------------------------------------------------------
  Level 1 Locks: VMDBK/SHRBK queue lock (VMDSHRLK)
                 DEFSEG/SAVESEG exclusive command lock
                   (NSUDSGLK)
                 DEFSYS/SAVESYS symbolic command lock
                   (NSUDSYAN)
  Level 2 Lock:  *NSS SDF queue lock (NSUSDFLK)
  Level 3 Lock:  Named Saved System SNTBK queue lock
                 (NSUSYQLK)
  Level 4 Lock:  Saved Segment SNTBK queue lock (NSUSGQLK)
  Level 5 Lock:  SNTBK/SHRBK queue lock (SNTSHRLK) for one of
                   Member Saved Segment, DCSS, or Named Saved
                   System
  Level 6 Lock:  SNTBK/SHRBK queue lock (SNTSHRLK) for Segment
                   Space
  Note: 1) The level 1 locks are the hightest level locks and
           the level 6 locks are the lowest level locks.
        2) If locks need to be obtained from different levels,
           then the higher level lock needs to be obtained
           first.
        See the definition and description of each individual
        lock for more detailed information.
  Saved Segment or Named Saved System serialization matrix
  --------------------------------------------------------
          +-----------------+-----+-----+-----+-----+-----+
          |      LVL1       | LVL2| LVL3| LVL4| LVL5| LVL6|
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  | Func- | VMD | Def | Def | *NSS| NSS | Sseg| SNT | SNT |
  | tion  | SHR | Save| Save| SDF |  Q  |  Q  | SHR | SHR |
  |       |  Q  | seg | SYS |  Q  | lock| lock|  Q  |  Q  |
  |       | lock| cmd | cmd | lock|     |     | Lock| Lock|
  |       |     | lock| lock|     |     |     |     |(SSP)|
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |DEFSEG |     | exc |     | exc |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |SAVESEG|     | exc |     | exc |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |DIAG 64|     |     |     |     |     | shr |     |     |
  |Find-1 |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |DIAG 64|     |     |     | exc |     |     |     |     |
  |Find-2 |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |DIAG 64| exc |     |     |     |     | shr | exc | exc |
  |Load-1 |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |DIAG 64| exc |     |     | exc |     | exc |     |     |
  |Load-2 |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |DIAG 64| exc |     |     |     |     | shr | exc | exc |
  |Purge1 |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |DIAG 64| exc |     |     | exc |     | exc |     |     |
  |Purge2 |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |Q NSS  |     |     |     | exc |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |Q NSS  |     |     |     |     | shr | shr | shr | shr |
  |USERS  |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |Inter  | exc |     |     |     | shr | shr | exc | exc |
  |Purge-1|     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |Inter  | exc |     |     | exc | exc | exc |     |     |
  |Purge-2|     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |DEFSYS |     |     | exc | exc |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |SAVESYS|     |     | exc | exc |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  | IPL   | exc |     |     | shr | shr |     | exc |     |
  | NSS-1 |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  | IPL   | exc |     |     | exc | exc |     |     |     |
  | NSS-2 |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |Monitor|     |     |     |     | shr | shr |     |     |
  |Sample |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |Monitor| shr |     |     |     |     |     |     |     |
  | IUCV  |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  | Purge |     |     |     | exc | exc | exc |     |     |
  | Cmd   |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  | Indi- |     |     |     |     | shr | shr |     |     |
  | cate  |     |     |     |     |     |     |     |     |
  | NSS   |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |VMdump | exc |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  |Mig-   |     |     |     |     | shr | shr |     |     |
  |rator  |     |     |     |     |     |     |     |     |
  +-------+-----+-----+-----+-----+-----+-----+-----+-----+
  Notes:
  DIAG 64 Find-1 : Find a Saved Segment from the Saved Segment
                   SNTBK queue
  DIAG 64 Find-2 : Find a Saved Segment from the *NSS SDF
                   queue
  DIAG 64 Load-1 : Load a Saved Segment from the Saved Segment
                   SNTBK queue.
  DIAG 64 Load-2 : Load a Saved Segment from the *NSS SDF
                   queue
  DIAG 64 Purge1 : 'use-count' > 1, not the last user.
  DIAG 64 Purge2 : 'use-count' = 1, last user of the Saved
                   Segment.
  Inter Purge-1  : 'Internal' Purge, 'use-count' > 1, not the
                   last user.
  Inter Purge-2  : 'Internal' Purge, 'use-count' = 1, last
                   user of the Saved Segment.
  IPL NSS-1      : IPLing a Named Saved System from the Named
                   Saved System SNTBK queue
  IPL NSS-2      : IPLing a Named Saved System from the *NSS
                   SDF queue
 
 
  NSUBK Control Block Content Top of page
 

 NSUBK DSECT Top of page
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure NSUBK Auxillary Storage Management utility data Saved Segment SNTBK Queue lock (NSUSGQLK) Lock type: This is a formal shared or exclusive lock Resource serialized: This lock will serialize the Saved Segment SNTBK queue. The lock will be obtained shared when scanning the Saved Segment SNTBK queue and exclusive when adding to, or deleting from, the queue. Notes : If the *NSS SDF queue lock is held exclusively then the Saved Segment SNTBK queue can be scanned without holding the queue lock. This is because the *NSS SDF queue lock must be held exclusively to add or remove a SNTBK from the Saved Segment SNTBK queue. 0000 0 Dbl-Word 8 NSUSGQLK (3) Shared/exclusive defer lock to serialize the queue of Saved Segment SNTBKs anchored at NSUNSGAN Saved Segment SNTBK Queue anchors 0018 24 Dbl-Word 8 NSUNSGAN (0) Anchors to queue of Saved Segment SNTBKs 0018 24 Address 4 NSUNSGFW Foward pointer of Saved Segment SNTBKs 001C 28 Address 4 NSUNSGBK Backward pointer of Saved Segment SNTBKs Named Saved System SNTBK Queue lock (NSUSYQLK) Lock type: This is a formal shared or exclusive lock Resource serialized: This lock will serialize the Named Saved System SNTBK queue. The lock will be obtained shared when scanning the Named Saved System SNTBK queue and exclusive when adding to, or deleting from, the queue. Notes : If the *NSS SDF queue lock is held exclusively then the Named Saved System SNTBK queue can be scanned without holding the queue lock. This is because the *NSS SDF queue lock must be held exclusively to add or remove a SNTBK from the Named Saved System SNTBK queue. 0020 32 Dbl-Word 8 NSUSYQLK (3) Shared/exclusive defer lock to serialize the queue of NSS SNTBKs anchored at NSUNSYAN NSS SNTBK Queue anchors 0038 56 Dbl-Word 8 NSUNSYAN (0) Anchors to queue of NSS SNTBKs. 0038 56 Address 4 NSUNSYFW Foward pointer of NSS SNTBKs. 003C 60 Address 4 NSUNSYBK Backward pointer of NSS SNTBKs. IMG SNTBK Queue anchors and queue lock 0040 64 Dbl-Word 8 NSUIMGLK (6) Lockword for image SNTBK queue lock. 0070 112 Dbl-Word 8 NSUIMGAN (0) Anchors to image HCPSNTBK queue. 0070 112 Address 4 NSUIMGFW Foward pointer of HCPSNTBK image queue. 0074 116 Address 4 NSUIMGBK Backward pointer of HCPSNTBK image queue. NLS SNTBK Queue anchors and queue lock 0078 120 Dbl-Word 8 NSUNLSLK (6) Lockword for NLS SNTBK queue lock. 00A8 168 Dbl-Word 8 NSUNLSAN (0) Anchors to queue of NLS SNTBKs. 00A8 168 Address 4 NSUNLSFW Foward pointer of NLS SNTBKs. 00AC 172 Address 4 NSUNLSBK Backward pointer of NLS SNTBKs. Saveseg SNTBK Queue anchors Notes : This queue is serialized by *NSS SDF queue lock NSUSDFLK. 00B0 176 Dbl-Word 8 NSUSSGAN (0) Anchors to queue of SAVESEG SNTBKs 00B0 176 Address 4 NSUSSGFW Foward pointer of SAVESEG SNTBKs 00B4 180 Address 4 NSUSSGBK Backward pointer of SAVESEG SNTBKs Savesys SNTBK Queue anchors Notes : This queue is serialized by *NSS SDF queue lock NSUSDFLK. 00B8 184 Dbl-Word 8 NSUSSYAN (0) Anchors to queue of SAVESYS SNTBKs 00B8 184 Address 4 NSUSSYFW Foward pointer of SAVESYS SNTBKs 00BC 188 Address 4 NSUSSYBK Backward pointer of SAVESYS SNTBKs 00C0 192 Signed 4 * (2) Reserved for future IBM use DEFSEG/SAVESEG exclusive command lock (NSUDSGLK) Lock type: This is a formal exclusive lock Resource serialized: This lock serializes the DEFSEG and SAVESEG commands. Only one DEFSEG or SAVESEG command can be processed at one time. 00C8 200 Dbl-Word 8 NSUDSGLK (3) Exclusive defer lock to serialize the DEFSEG/SAVESEG command DEFSYS/SAVESYS symbolic command lock (NSUDSYAN) Lock type: This is a formal exclusive symbolic name lock. Resource serialized: This lock serializes the DEFSYS and SAVESYS commands for the Named Saved System that is being defined or saved. Only one DEFSYS or SAVESYS can be processed for a particular Named Saved System at any given time. 00E0 224 Dbl-Word 8 NSUDSYAN Symbolic queue lock anchor to serialize the DEFSYS/SAVESYS command *NSS SDF queue lock (NSUSDFLK) Lock type: This is a formal shared or exclusive lock Resource serialized: This lock will serialize the *NSS SDF queue, the SAVESEG SNTBK queue, and the SAVESYS SNTBK queue. Functions serialized: This lock must be obtained exclusive to open any "*NSS" spool file for read or write. It is also used to add or remove SNTBKs from the SAVESEG SNTBK queue and the SAVESYS SNTBK queue. Notes : If the *NSS SDF queue lock is held exclusively then the Named Saved System SNTBK queue or Saved Segment SNTBK queue can be scanned without holding the queue lock. This is because the *NSS SDF queue lock must be held exclusively to add or remove a SNTBK from the Named Saved System SNTBK queue or the Saved Segment SNTBK queue. 00E8 232 Dbl-Word 8 NSUSDFLK (3) Exclusive defer lock to serialize the queue of SDFs owned by user *NSS SDF multiple symbolic lock manager (NSUMSLKM) Lock type: This is a formal exclusive lock Functions serialized: This lock will be obtained by any CP function (such as "Purge IMG/NLS ALL") that needs to obtain multiple symbolic name locks for NLS/IMG files. 0100 256 Dbl-Word 8 NSUMSLKM (3) Exclusive defer lock to serialize entry points that obtain multiple symbolic locks IMG/NLS SDF symbolic queue lock anchor 0118 280 Dbl-Word 8 NSUSYMAN Symbolic queue lock anchor for IMG and NLS system data files.
 
 
  NSUBK Storage Layout Top of page
 
          
*** NSUBK - Auxillary Storage Management utility data
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       NSUSGQLK                        =
*     |                                                       |
*     +---------------------------+---------------------------+
*  18 |         NSUNSGFW          |         NSUNSGBK          |
*     +---------------------------+---------------------------+
*  20 |                                                       |
*     =                       NSUSYQLK                        =
*     |                                                       |
*     +---------------------------+---------------------------+
*  38 |         NSUNSYFW          |         NSUNSYBK          |
*     +---------------------------+---------------------------+
*  40 |                                                       |
*     =                       NSUIMGLK                        =
*     |                                                       |
*     +---------------------------+---------------------------+
*  70 |         NSUIMGFW          |         NSUIMGBK          |
*     +---------------------------+---------------------------+
*  78 |                                                       |
*     =                       NSUNLSLK                        =
*     |                                                       |
*     +---------------------------+---------------------------+
*  A8 |         NSUNLSFW          |         NSUNLSBK          |
*     +---------------------------+---------------------------+
*  B0 |         NSUSSGFW          |         NSUSSGBK          |
*     +---------------------------+---------------------------+
*  B8 |         NSUSSYFW          |         NSUSSYBK          |
*     +---------------------------+---------------------------+
*  C0 |///////////////////////////////////////////////////////|
*     +-------------------------------------------------------+
*  C8 |                                                       |
*     =                       NSUDSGLK                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  E0 |                       NSUDSYAN                        |
*     +-------------------------------------------------------+
*  E8 |                                                       |
*     =                       NSUSDFLK                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 100 |                                                       |
*     =                       NSUMSLKM                        =
*     |                                                       |
*     +-------------------------------------------------------+
* 118 |                       NSUSYMAN                        |
*     +-------------------------------------------------------+
* 120
*
*** NSUBK - Auxillary Storage Management utility data
 
 
  NSUBK Cross Reference Top of page
 
 
Symbol         Dspl Value
-------------- ---- -----
NSUDSGLK       00C8
NSUDSYAN       00E0
NSUIMGAN       0070
NSUIMGBK       0074
NSUIMGFW       0070
NSUIMGLK       0040
NSUMSLKM       0100
NSUNLSAN       00A8
NSUNLSBK       00AC
NSUNLSFW       00A8
NSUNLSLK       0078
NSUNSGAN       0018
NSUNSGBK       001C
NSUNSGFW       0018
NSUNSYAN       0038
NSUNSYBK       003C
NSUNSYFW       0038
NSUSDFLK       00E8
NSUSGQLK       0000
NSUSSGAN       00B0
NSUSSGBK       00B4
NSUSSGFW       00B0
NSUSSYAN       00B8
NSUSSYBK       00BC
NSUSSYFW       00B8
NSUSYMAN       0118
NSUSYQLK       0020
 
This information is based on z/VM 7.1.0 Last updated on 22 Jun 2018 at 11:51:13 EDT.
Copyright IBM Corporation, 1990, 2018