Type ASSEMBLE
Source Lines : 1,534
Fixes Applied : 16
Most Recent Version : Thursday, December 14, 1978
Last Fix ID : [HRC106DK]
Module
DMKVDC
Function
TO ACQUIRE FREE STORAGE IN ADVANCE FOR VIRTUAL BLOCKS
FOR ALL THOSE DEVICES WHICH ARE LIKELY TO BE ATTACHED
ON THIS COMMAND EXECUTION.
Attributes
REENTRANT, PAGEABLE, CALLED VIA SVC
Operation
1. ACQUIRE FREE STORAGE WORK AREA FOR COUNTERS ETC.
2. FIND RDEVBLOK FOR SPECIFIED ADDRESS
IF THE DEVICE IS OFFLINE OR ALREADY DEDICATED, PROCESS
NEXT ADDRESS.
3. ACQUIRE IOBLOK AND CPEXBLOK AND SCHEDULE TIO TO THE
DEVICE BY CALLING DMKIOSQR. IF THE DEVICE DOES NOT EXIST,
SKIP TO PROCESS NEXT ADDRESS.
4. SEE IF VIRTUAL DEVICE IS ALREADY DEFINED (DMKSCNVU).
IF THE DEVICE IS ALREADY DEFINED, SKIP TO PROCESS NEXT
ADDRESS. IF THE CHANNEL IS DEDICATED, SKIP TO PROCESS
NEXT DEVICE. OTHERWISE, KEEP A COUNTER FOR THE NUMBER
OF VCHBLOKS/VCUBLOKS/VDEVBLOKS WHICH ARE LIKELY TO BE
CREATED IN THIS COMMAND EXECUTION. PERFORM THIS FUNCTION
FOR ALL ADDRESSES IN THE RANGE/ALL MULTIPLE DEVICE ADDRESSES.
5. RELEASE IOBLOK AND CPEXBLOK AFTER THIS PHASE IS COMPLETE.
6. DETERMINE NUMBER OF UNUSED (EMPTY SLOTS) IN CURRENT
TABLES OF VCHBLOKS/VCUBLOKS/VDEVBLOKS.
7. SUBTRACT NUMBER OF BLOCKS OF EACH TYPE WHICH WILL BE
CREATED AS A RESULT OF THIS COMMAND EXECUTION FROM THE NUMBER
OF CURRENTLY AVAILABLE BLOCKS OF EACH TYPE TO DETERMINE THE
EXACT NUMBER OF NEW VCHBLOKS/VCUBLOKS/VDEVBLOKS WHICH MUST BE
CREATED IN THIS COMMAND EXECUTION.
8. ACQUIRE STORAGE FOR NEW VIRTUAL BLOCKS REQUIRED BY
CALLING DMKFRERC. IF STORAGE CANNOT BE OBTAINED, RETURN TO
DMKVDA WITH GPR2=32. DMKVDA WILL THEN ISSUE ERROR MESSAGE
DMKVDA131E. MOVE OLD TABLE OF VCHBLOKS/VCUBLOKS/VDEVBLOKS
TO NEWLY ACQUIRED TABLES AND MARK ALL ADDITIONAL BLOCKS AS
EMPTY SLOTS. @VA13217
9. RELEASE WORK AREA AND EXIT.
Calls to Other Routines
DMKFRERC - ACQUIRE FREE STORAGE WITH RETURN CODE IN REQUEST
CANNOT BE SATISFIED.
DMKSCNRU - FIND RDEVBLOK
DMKIOSQR - SCHEDULE I/O REQUEST FOR TIO
DMKSCNVU - FIND VIRTUAL BLOCKS
DMKVIOMK - ADDRESS OF MASK TABLE