USER DIRECTORY ROUTINES D8KUDRFU -- Entry after CP detected LOGON command. DMKSYSPL points to
directory. Determine length of userid, if valid call D8KLOCKQ. Lock the directory in storage. the
Bring in each directory
buffer) until a UDIRBLOK detected.
page and return each page (and clear the
match occurs or directory's last page is DMKU DR, FIN DU S ER ---on-userId-fonnd, move UDIRBLOK to caller's area. DMKLQ£!2 Unlock the directory in storage • .......... n'r"\.n 'OVTm,...,...n Return to caller. DMKUDRFD from calling routine to find the addressed (cuu) device UDEVBLOK in users directory and move it to the caller. Via UMACBLOK locate the UDEVBLOKs. DMKUDR, FINDDEV -- if the user device address is the same as in the UDEVBLOK. Search the chain until match or end of chain occurs. DMKUDR, For found condition, post condition code zero in user's VMPSW. DMKUDRRD from calling routine to read the UDEVBLOK addressed into the
caller's buffer. Using the DASD and the user displacement from the UMACBLOK, bring in the buffer page to storage. Determine if the
virtual directory page address (UDBFVIDD) exists in the user
directory buffer blocks. If not call- DKKPGTVG ---and-get a virtual page. DMKRPIGT ---Por-DASD address does not match the UMICBLOK, point to the D1SD page
and bring in the virtual buffer page. Move UDEVBLOK into callers area
and set cc=O in VMPSW. Return to caller. Entry to return a virtual page USed as a buffer. Determine if UDBFBLOK contains a virtual buffer page pointer (UDBFVADD). If not,
exit with cc=1 set in the VKPSW. If a buffer exists, check to see if
it is resident; if it is, clear it to zeros. Return the real page to the system. Return the virtual page to the system. DMKtJDRRV -- Set-cc=O and return to caller. DMKUDRBV -- Entry from DMKDIRCT or DKKCPINT to build page buffers for each UDIRBLOK. Get storage for the virtual buffer page list. Call DMKPGTVG and DMKRPIGT to get the virtual and real buffer. Save the virtual buffer address in the page list. Encountered 1/0 error, free the virtual buffer page list, post fatal
message, set cc=3 and return to caller. DKKUDR, ENDLIST ---swap the-new virtual buffer page list with the old list. Anchor the
new list to DKKSYSPL. CP Method of Operation and Program Organization 1-223

If there was a previous buffer page list, free it. Save the start of
the user directory pointer in DMKSYSUD, and return to caller with a cc=O in the VMPSi. SAVE THE 3704/3705 CONTROL PROGRAM IMAGE PROCESS Entry from DMKHVC and DIAGNOSE code 50. Per the system VMBLOK, locate the DftKRNTBL. The CCPARM virtual address is contained in R1 of
the DIAGNOSE instruction. Match via search CCPARM; CCPNAME with DMKRNTBL entries. Verify DASD space requirements for 3704/3705 control program and
resource data. The volume required to save (NCPVOL) as indicated in
the NCPTBL entry must be available and mounted on the system, on a CP owned and supported paging device. Save resource data on the NCPVOL device. CCPARM supplies the starting
address and size parameters for this write operation. 12!1KS!!£, SVN£fl!! Save 3704/3705 control program image on NCPVOL device. CCPARM also
provides the parameters for this similar operation. Store cc=O on no errors and return to caller. SPOOL PILE CHECKPOINT AND RECOVERY Entry from CP initializer, DMKCPI to initialize the checkpoint
cylinders. Per DMKSYSCH, get a virtual page for the checkpoint
cylinder and set up the device code in the system residence device.
In addition, set up local data areas such as pages per cylinder and
checkpoint cylinders. Loop through each SPBLOK in the system and checkpoint it in a slot on
the checkpoint cylinder. Then loop through each remaining slot and
mark it empty. Place the map delimiter of the last non-empty slot in the aap. DMKPTRUL -- Unlock the map page. Return to caller. DMKCKSPL from any routine that adds, deletes, changes, the status of
closed spool files. Lock the routine, or wait until it becomes
unlocked. Bring the aap page into storage and set up the device code
of the system residence volume.
1-224 IBM VM/370 System Logic and Problem Determination--Voluae 1