Type ASSEMBLE
Source Lines : 439
Fixes Applied : 7
Most Recent Version : Thursday, December 7, 1978
Last Fix ID : [HRC039DK]

Module

       DMKVDR

Function

       TO PERFORM THE NECESSARY FUNCTIONS TO RELEASE A REAL OR
       VIRTUAL DEVICE FROM A VIRTUAL MACHINE.

Attributes

       REENTRANT, PAGEABLE, CALLED VIA SVC

Operation

       1.  A CALL IS MADE TO DMKCFPRD TO RESET THE DEVICE AND
       CLEAR ANY ACTIVE IOBLOK OR PENDING I/O INTERRUPTS.

       2.  CHECKS ARE THEN MADE TO SEE IF THE DEVICE IS DEDICATED,
       A DISK STORAGE DEVICE, A UNIT RECORD DEVICE, A SPECIAL
       DEVICE, OR A CONSOLE DEVICE.  (IF NONE OF THESE, AN ABEND
       VIA SVC 0 IS GENERATED, INDICATING AN INTERNAL CODING ERROR.)

       3.  DEDICATED DEVICE:  THE RDEVBLOK ADDRESS IS OBTAINED FROM
       THE VDEVBLOK, AND ITS ADDRESS IS THEN CLEARED.  IF THE DEVICE
       IS A TAPE, AN IOBLOK TO REWIND AND UNLOAD THE TAPE IS BUILT,
       AND DMKIOSQR IS CALLED TO START THE OPERATION.  IN ANY EVENT,
       THE DMKACODV ACCOUNTING ROUTINE IS CALLED, THE DEDICATED FLAG
       BITS IN THE RDEVBLOK AND VDEVBLOK ARE CLEARED, THE OPERATOR IS
       SENT A MESSAGE THAT THE DEVICE HAS BEEN RELEASED (BY WHAT
       USER), AND RETURN IS MADE.

       4.  DISK STORAGE DEVICE:  THE RDEVBLOK ADDRESS IS OBTAINED
       FROM THE VDEVBLOK, AND ITS ADDRESS (VDEVREAL) IS THEN CLEARED.
       IF THE DEVICE IS A T-DISK, DMKACODV IS CALLED TO BUILD AN
       ACCOUNTING RECORD.  THEN DMKTDKRL IS CALLED TO RETURN THE
       T-DISK SPACE TO THE SYSTEM, AND RETURN IS MADE.  IF NOT, THE
       COUNT OF LINKS TO THE DISK IN THE RDEVBLOK IS DECREMENTED, AND
       THE CHAIN OF LINKS TO THE DISK ACCESSIBLE VIA THE VDEVBLOK IS
       ADJUSTED TO DELETE THE CALLER'S USERID.  RETURN IS THEN MADE.

       5.  UNIT RECORD DEVICE:  IF NO FILES ARE OPEN, RETURN IS MADE.
       IF YES, THEN DMKVSPCO IS CALLED TO CLOSE THE PRINTER OR PUNCH,
       OR DMKVSPCR IS CALLED TO CLOSE THE READER, AND RETURN IS MADE.

       6.  SPECIAL DEVICE:  IF THE DEVICE IA A VIRTUAL CHANNEL-
       TO-CHANNEL ADAPTER (CTCA), DMKVCARS IS CALLED TO RESET THE
       UNIT AND DISCONNECT IT FROM ANOTHER ADAPTER, IF NEEDED.
       IF IT IS NOT A VIRTUAL CTCA, RETURN IS IMMEDIATE.

       7.  CONSOLE DEVICE: IF THE DEVICE IS NOT A 1052 TYPE DEVICE,
       EXIT IS IMMEDIATELY MADE TO THE CALLER.  IF CONSOLE SPOOL
       FILE IS ACTIVE; CALL DMKVSPCO TO CLOSE THE FILE.
       RETURN IS THEN MADE TO THE CALLER.

Calls to Other Routines

       DMKCFPRD
       DMKACODV
       DMKCVTBH
       DMKQCNWT
       DMKFREE
       DMKSCNRD
       DMKSCNRN
       DMKIOSQR
       DMKTDKRL
       DMKVSPCR
       DMKVSPCO
       DMKVCARS
       DMKFRET
       DMKPTRPW