Type ASSEMBLE
Source Lines : 2,127
Fixes Applied : 13
Most Recent Version : Thursday, December 14, 1978
Last Fix ID : [HRC106DK]
Module
DMKMON
Function
TO PROCESS COMMANDS AND REQUESTS ASSOCIATED WITH THE
MONITOR, INCLUDING MONITOR CALL INTERRUPTS WITHIN THE
CONTROL PROGRAM.
Attributes
REENTRANT, PAGABLE,
CALLED VIA:
BRANCH FROM DMKPRG
RE-ENTERED VIA:
IOBLOK IRA AFTER MONITOR TAPE I/O INTERRUPT.
TRQBLOK IRA AFTER TIME LAPSE EXPIRATION.
Operation
MONITOR CALL INTERRUPT PROCESSING
DMKMONMI:
THE MONITOR CALL CLASS AND CODE ARE RETREIVED FROM
PSA AND A BRANCH IS MADE TO THE APPROPRIATE MONITOR
CLASS ROUTINE.
FROM THE APPROPRIATE MONITOR CLASS ROUTINE A BRANCH
IS MADE TO THE APPROPRIATE MONITOR CODE ROUTINE
(THE DATA COLLECTION ROUTINE).
EACH ROUTINE COLLECTING DATA CALLS THE BUFFER
MANAGEMENT ROUTINE FOR THE AMOUNT OF SPACE NEEDED
TO CONTAIN THE SPECIFIC RECORD.
THE FOLLOWING IS A SUMMARY OF WHAT DATA EACH OF THE
VARIOUS ROUTINES COLLECTS, AND THE COLLECTION
VEHICLE.
CLASS 0 - PERFORM (TIMER DRIVEN)
CODE 0 - COLLECT SYSTEM CLOCKS AND
COUNTERS.
CODE 1 - COLLECT APU CLOCKS AND COUNTERS.
CODE 97 - MONITOR TAPE HEADER RECORD,
CREATED BY DMKMONTH.
CODE 98 - MONITOR TAPE TRAILER RECORD,
CREATED BY DMKMONIO.
CODE 99 - MONITOR SUSPENSION DUE TO TAPE
BUSY, CREATED BY DMKMONIO.
CLASS 1 - RESPONSE (MONITOR CALL)
CODE 0 - BEGIN A CONSOLE READ.
CODE 1 - CONSOLE OUTPUT.
CODE 2 - END A CONSOLE READ.
CODE 3 - BEGIN SLEEP WITH TIME OUT.
CODE 4 - USER LOGON
CODE 5 - USER LOGOFF
CLASS 2 - SCHEDULER (MONITOR CALL)
CODE 2 - DROP USER FROM Q.
CODE 3 - ADD USER TO Q.
CODE 4 - ADD USER TO ELIGABLE LIST.
CLASS 3 - RESERVED (MONITOR CALL)
CLASS 4 - USER (TIMER DRIVEN)
CODE 0 - COLLECT VIRT. MACH STATISTICS.
CLASS 5 - INSTRUCTION SIMULATION (MONITOR CALL)
CODE 0 - BEGIN INSTRUCTION.
CLASS 6 - DASTAP (TIMER DRIVEN)
CODE 0 - INITIALIZE AND CREATE DASTAP
HEADER, CALLED FROM DMKMONTH.
CODE 1 - COLLECT DEVICE INFORMATION.
CLASS 7 - SEEKS (MONITOR CALL)
CODE 0 - DASD SEEK CHANNEL PROGRAM ISSUED.
CLASS 8 - SYSPROF (MONITOR CALL - VIA CLASS 2)
CODE 2 - COLLECT DEVICE I/O COUNTS AND
SYSTEM CLOCKS.
AFTER THE APPROPRIATE MONITOR DATA IS COLLECTED THE
GENERAL REGISTERS ARE RESTORED FROM DMKPRG AND
SYSTEM PROCESSING RESUMES FROM THE PROGRAM OLD
PSW.
BUFFER MANAGEMENT:
THE BUFFER MANAGEMENT ROUTINE MAINTAINS A POINTER
TO THE BUFFER CURRENTLY COLLECTING DATA. IF A RECORD
IS REQUESTED WHICH OVERFLOWS THE BUFFER, OR IF ONLY ONE
BUFFER IS BEING USED AND THE NEXT RECORD WOULD OVERFLOW
THE BUFFER, THEN A POINTER TO THE NEXT AVAILABLE BUFFER
IS GOTTEN, AND CONTROL IS PASSED TO THE TAPE MANAGEMENT
ROUTINE TO WRITE OUT THE BUFFER.
TAPE I/O MANAGEMENT:
THE TAPE MANAGEMENT ROUTINE KEEPS TRACK OF THE
CURRENT STATUS OF THE TAPE. IF THE TAPE IS NOT
BUSY THEN A CPEXBLOK IS STACKED WHICH WILL CALL
DMKIOSQR TO WRITE THE BUFFER TO TAPE. AFTER THE
CPEXBLOK IS STACKED, RETURN IS MADE FROM WHENCE WE
CAME.
IF THE TAPE IS BUSY, INDICATION IS MADE THAT I/O IS
PENDING, SO THAT THE I/O INTERRUPT HANDLER WILL RE-START
THE TAPE WHEN THE CURRENT I/O FINISHES.
NOTE: WHEN THE CPEXBLOK IS UNSTACKED BY THE
DISPATCHER A CALL IS MADE TO DMKFREE TO REPLACE THE
BACK POCKET CPEXBLOK. THIS WILL NOT CAUSE AN
EXTEND SINCE THE DISPATCHER JUST UNSTACKED AND
FRETED THE CPEXBLOK. ALTHOUGH THE DISPATCHER FRET
MAY HAVE CAUSED A DIS-EXTEND, RESULTING IN AN
EXTEND ON THIS CALL; THIS EXTEND WOULD NOT INVOLVE
I/O.
SUSPENSION:
IF NO BUFFERS ARE AVAILABLE THEN MONITORING IS SUSPENDED.
IN THIS CASE, EACH BUFFER IS EITHER BEING WRITTEN TO
TAPE, OR WAITING TO BE WRITTEN. A COUNT IS MAINTAINED
IN THIS CASE, THERE ARE 2 FULL BUFFERS OF DATA.
ONE HAS BEEN SCHEDULED TO GO TO TAPE BUT THE TAPE
I/O HAS NOT COMPLETED AND THE OTHER BUFFER IS FULL
AND WAITING TO GO TO TAPE. A COUNT IS MAINTAINED
OF THE NUMBER OF TIMES THAT THIS CONDITION
OCCURRS. A NOTE IS MADE THAT THE MONITOR IS
SUSPENDED, ALONG WITH THE CURRENT TOD CLOCK VALUE.
AT THIS POINT THE REASON FOR ENTRY INTO DMKMON IS
IGNORED AND EXIT IS MADE BACK TO DMKPRG IF ENTRY
WAS VIA AN MC INSTRUCTION OR TO THE DISPATCHER IF
ENTRY WAS MADE VIA A TIMER INTERRUPT. THE MONITOR
IS LEFT DISABLED FOR MC INTERRUPTS. IF A MONITOR
TIMER INTERRUPT SHOULD OCCUR, THEN THE TIMER
ROUTINE WILL BE DECEIVED INTO THINKING THAT THERE
ARE NO EVENTS TO MONITOR. HOWEVER, THE NEXT TIMER
INTERRUPT IS SET UP BEFORE HE EXITS TO THE
DISPATCHER, SO THE TIMER INTERRUPT PROCESS IS NOT
FORGOTTEN.
THE MONITOR I/O INTERRUPT HANDLER WILL DETECT THE
SUSPEND CONDITION AND DO WHAT IS NECESSARY TO
RESUME MONITORING. SEE THE I/O INTERRUPT HANDLER
FOR DETAILS OF THAT FUNCTION.
Calls to Other Routines
DMKIOSQR - TO INITIATE I/O FOR JUST FILLED DATA PAGE