VTAM locks

Table 1 includes a description of each VTAM® lock, and Figure 1 provides information on VTAM lock pointers.

Table 1. VTAM locks

 
Name

Lock
ID

 
Lvl

Hex
value

Control
block

 
Field name

 
Quantity

 
Function
8SLOCK 1 3 04 MPNCB MPN8SLK One per multipath channel (MPC) line represented by an MPNCB Serializes MPC outbound scheduling in a VTAM operating under MVS™ with multiple CPUs and System/390® or System z® hardware. Ensures single remover for TPREMEL macros.
ADJLOCK 4 5 10 ADJSA ATCADJLK One per VTAM Protects users of CIDCTL when adding or deleting an adjacent node.
AHHCLOCK 71 11 400 ISTTSEXT TSEXT_LK One per VTAM Serializes access to the AHNCB queue in the TSEXT.
AHNCBLOK 31 5 10 AHNCB AHNLOCK One per active APPN host-to-host channel PU Serializes AHNCB PU PAB with AHNCB PC PAB.
ASBREG 53 7 40 MNPS MNPS_ALK One per MNPS application Serializes use of the pending registered CFS user's queue.
AULINLOK 63 8 80 AULIN AULINLOK One per VTAM Serialize updates and references to list of Enterprise Extender lines.
AUVTLOCK 68 7 40 ISTAUVT AUVTLOK One per VTAM Serializes access to two Enterprise Extender resources. One is a control block which represents a local IPADDR and the other is a control block which represents a resolved HostName.
BPBLOCK 38 3 04 BPB BPBLOCK One BPB per boundary function NCB Protects BSB PCID and BSBSA tree for SNA/IP and rapid-transport protocol (RTP).
BSBLOCK 39 4 08 BSB BSBLOCK One per session using VTAM boundary Protects updates and references of the BSB.
CIDLOCK 32 8 80 CIT CITLOCK One per session Serializes changes to or deletion of FMCB.
CLKLOCK 69 9 100 ISTCLK CLK_LOCK One per VTAM Serializes ISTRPCTM with HPRTIMER invokers.
CLWLOCK 70 9 100 ISTCLW CLW_LOCK One per VTAM Serializes ISTAUCTM with IPTTIMER invokers.
CMMEMLOK 48 10 200 CMDAT CMMEMLPT One per VTAM Serializes access to list of large buffers allocated by CMIP.
CMPLLOCK 46 5 10 CMPVT CMP_LLNK One per VTAM Serializes access to list of active CMIP applications.
CMRPLOCK 45 5 10 CMDAT CMRPLPTR One per VTAM Serializes access to data owned by CMIP replication and management information base (MIB) controller.
CONVLOCK 33 9 100 CONVT CONVTLOK One per APPC conversation Serializes deletions of RAB.
CRYTOKLK 26 8 80 ATCVT ATCRYKLW One per VTAM Serializes use of the session key token chain.
DEBX2LOK 27 6 20 DEBX DEBX2_LK One per ACB index table entry Serializes queuing of an application API requests with the closing of an ACB.
DEBLOCK 6 5 10 ACDEB ACDLOCK One per OPEN application program

1. Protects FMCB queue
off ACDEB.
2. Held by TSC and by
OPEN or CLOSE.
DESCQLOK 62 7 40 INSTANC
EDATA		 DESCQ_LOCK One per VTAM Synchronizes removing of list descriptors from the list descriptor queue.
DWALOCK 15 8 80 DWA DWALOCK One per VTAM Used by certain disabled TSC modules to serialize use of the disabled work area (DWA).
FSEXTPLK 66 11 400 ISTFSEXT FSEXTPLK One per VTAM Serializes queuing and dequeuing of the CFUSR block to PSTCFUSR queue. Serializes release of PST storage.
GENRSDEF 61 7 40 ISTGENRS GENRS_LK One per VTAM Synchronizes queueing to the defer queue from RVM and the processing of the defer queue.
HITLOCK 41 3 04 HIT HITLOCK One per FID5 session address Protects users of HPRCTL when assigning or deleting a FID5 address or when acquiring a BSB address through FID5 address lookup.
HNTELOCK 5 7 40 HNTE HNTELOCK One per minor node (per host element address) Serializes updates and references to control blocks based off the HNTE (RDTE, NCB, LUCB, FMCB).
HNTERBLK 23 8 80 HNT HNTERBLK One per minor node Serializes APPC conversion data in the RAB.
HNTLOCK 7 6 20 HNT ATCHNTLK One Protects updates and references to HNT during most CIDCTL functions.
HPRPSLOK 74 9 100 HPRPS HPRPS_LOK One per VTAM Serialize access of the HPRPS control block.
HSQCHAIN 19 5 08 ATCVT ATCHSQLK One per VTAM Serializes usage of the HSQH queues. One lock is used to protect all of the queues.

IAPTREE

 40 2 02 SAACB SAAIAPLK One per VTAM Serializes modifications and references to the IAP tree.
INNLOCK 17 9 100 ATCVT ATCINNLK One per VTAM Ensures that PIUs that are going to a node that is in slowdown mode are sent in FIFO order.
IPNCBDIA 64 5 10 IPNCB IPNCBDIA One per VTAM Serialize access to the list of dial-in lines for Enterprise Extender.
IUSAPLOK 57 11 10 ISTPST IUSAPLOK One per PST Serializes APSINIT/APSTERM.
LKLNKSG 42 9 100 CMDAT CMDLKLNK One per VTAM Serializes access to certain control blocks of internal CMIP applications.
LMELLOCK 21 6 20 LME LMELLOCK One for every partner LU entry for every APPC application Used to serialize access to partner LU information in the APPC logical unit mode (LM) Table.
LMHTLOCK 22 5 10 LMHDR LMHTLOCK One per APPC application Used to serialize access to the APPC logical unit mode (LM) Table.
LSNLOCK 24 3 04 LSNCB LSNLOCKW One per PU connection to an IBM® 3172 Interconnect Nways Controller Serializes the LSNCB PU PAB with the LSNCB PC PAB.
LSVQLOCK 65 9 100 LSVT LSVQLOCK One per VTAM Serialize access of LSNCBs pending deallocation queue.
LUTABLOK 43 8 80 LUTAB LUTABLOK One per slot in the LU/NCE hash table Protects HPRCTL users when adding, deleting, updating, or finding LU entries in the LU/NCE table.
NCBQ 25 9 100 ATCVT ATCLNLOK One per VTAM Serializes access to the queue of LSA NCBs anchored at ATCLNNCB.
NODATLOK 72 9 100 NODAT NODAT_LOK One per VTAM Serializes adding/deleting NODAT_EEDisplay control blocks on the NODAT_EEDisplayQ.
PDBUFLK 18 9 100 ATCVT ATCBUFLK One per VTAM Allows the user to move in problem diagnosis trace data before the data is processed.
PSTIMERQ 59 7 40 CFSMNP PSTQ_LOK One per MNPS coupling facility structure represented by an MNPS structure object Serializes use the outstanding PSTimer queue.
PSTLOCK 8 8 80 ATCVT ATCPSTLK One per VTAM Serializes queuing and dequeuing of FMCB to PSTFMCB queue. Serializes release of PST storage.
QDCBLOCK 28 5 10 APNVT APNQDCBL One per VTAM Serializes access to the queue of QDCBs attached to the APNVT.
QUEUE 16 9 100 PAB PABLOCK One per extended PAB Serializes queuing and dequeuing of work elements to an extended PAB.
RDTLOCK 2 2 04 ATCVT ATCRDTLK One per VTAM Protects users of CIDCTL (PAFIND). Obtained by PUNS when a network-addressable unit is to be added or deleted, or a use count decremented.
RMCBLOK 58 5 10 IUTRMCB RMCSAPLK One per VTAM Serializes access to RM global IUSAP queue.
RMLCBLOK 56 7 40 RMLCB RMLCBLOK One per HPDT DLC Serializes NCBCMPAB work queues.
RPDCBLOK 55 7 40 ISTRPDCB RPDCBLOK One per RTP connection that a Performance Monitor (PMI) is monitoring Serializes the adding and deleting from the unsolicited data queue for RTP path switch and RTP deactivation.
RPNPMILC 54 5 10 ISTRPNCB RPNPMILK One per RTP connection that a Performance Monitor (PMI) is monitoring Serializes the collection of RTP data with the stop collection of data.
RTPHSQUE 49 5 10 RPNCB RPN_HSLK One per RPNCB Serializes access to each rapid-transport protocol (RTP) NCB's (RPNCB) half-session queue.
RTPTBLOK 47 8 80 RTPTB RTPTBLOK One per slot in the rapid transport protocol (RTP) hash table Protects HPRCTL users when adding, deleting, or finding RTPs in the RTP table.
RTPTBNLK 73 6 20 RTPTB RTPTBNLK One per VTAM Serializes access to all ISTRTPNIs and their ISTFRTPs. Protects HPRCTL find with wildcard against HPRCTL add and delete.

SKTASGN

 37 6 20 SAACB SAA_ASGN One per VTAM Serializes assignment of sessions to the socket tasks.

SKTLOCK

 36 8 80 SOTCB SOT_LOCK One per socket task (SOTCB) Protects SOCCB chain off the SOTCB.
SLENTLOK 29 5 10 SLENT SLE_LOCK One per session list entry Protects updates and references to the session list entry state indicators and to the sequential list of the TP work queue.
SSVCBLCK 67 11 400 ISTSSVCB CFSSSVLK 1024 per Sysplexports structure Serializes access to a list in the coupling facility Sysplexports structure.

TASKLOCK

 35 7 40 SAACB SAA_TASK One per VTAM Protects SOTCB chain off the SAACB.
TCEXTLOK 60 7 40 ISTTCEXT TCEXTLOK One per VTAM Serializes access to TLNCB list.
TOKENCOL 52 7 40 TOKENCOL COL_LOCK One per collection object Serializes access to the collection object.

TREELOCK

 34 6 20 SAACB SAA_TREE One per VTAM Protects the SOCCB tree.
VDLOCK 13 9 100 ATCVT ATCVDLOK One per VTAM Serializes directed load processor.
VOCLOCK 1 2 02 ATCVT ATCVOCLK One per VTAM
  1. Serializes OPEN/CLOSE with VARY.
  2. Serializes VARY Activate, VARY Deactivate, and VARY ERP.
VRLOCK 20 3 04 VRBLK VRBLOK One per virtual route Serializes usage of the VRBLK.
XCFCBLOK 50 9 100 XCFCB XCFCBLOK One (per VTAM) Serializes access to the XCF NCB AVL tree.
XFNCBLOK 51 5 10 XFNCB XFNCBLOK One per other VTAM node in the sysplex Serializes access to the XFNCB outbound data queues.
XHOTLOCK 44 9 100 CMPVT XHOTLPTR One per VTAM Serializes calls to a nonreentrant module that allocates autodata for C PABs.
Figure 1. Pointers to VTAM locks
Diagram that provides information on VTAM lock pointers.
Parent topic: Wait