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 zSeries® 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	Serializes OPEN/CLOSE with VARY. 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.