Type ASSEMBLE
Source Lines : 705
Fixes Applied : 9
Most Recent Version : Wednesday, December 13, 1978
Last Fix ID : [HRC004DK]
Module
DMKPSA
Function
TO PERFORM THE APPROPRIATE ACTIONS FOR VARIOUS
TYPES OF EXTERNAL INTERRUPT CODES.
Attributes
SERIALLY REUSABLE, RESIDENT
Operation
EXTERNAL INTERRUPTIONS ARE HANDLED AS FOLLOWS:
1. IF THE EXTERNAL INTERRUPT WAS FROM THE RED "INTERRUPT"
KEY ON THE 370 SYSTEM CONTROL PANEL, THE NECESSARY STEPS
(INCLUDING A CALL TO DMKQCNCL) ARE TAKEN TO CLEAR AND
DISCONNECT THE SYSTEM OPERATOR'S TERMINAL (IF HE IS LOGGED
ON, AND NOT ALREADY DISCONNECTED). THE SYSTEM OPERATOR IS
THEN ABLE TO LOG ON OR BE RECONNECTED AT ANY OTHER TERMINAL,
VIA THE 'LOGON' COMMAND. THE BUTTON INTERRUPT IS IGNORED FOR
ANY PROCESSOR OTHER THAN THE MAIN PROCESSOR IN AP SYSTEMS.
2. IF THE EXTERNAL INTERRUPT WAS DUE TO A TIMER INTERRUPT,
THE MACHINE MODE IS DETERMINED, AND ACTION TAKEN AS FOLLOWS:
A. IF THE MACHINE WAS IN PROBLEM MODE, THE ADDRESS OF
CURRENT USER'S VMBLOK IS OBTAINED FROM RUNUSER. THE
USER'S VIRTUAL PSW (VMPSW) IS UPDATED FROM THE EXTERNAL
INTERRUPT OLD PSW AND THE ADDRESS OF THE CURRENT VMBLOK
IS LOADED INTO GPR-11.
B. IF THE EXTERNAL INTERRUPT IS FROM THE CPU TIMER
AND THE VIRTUAL CPU TIMER IS CONTAINED IN THE REAL CPU
TIMER, A CALL IS MADE TO DMKTMRVT TO PROCESS THE
INTERRUPT. IF THE REAL CPU TIMER DOES NOT CONTAIN THE
VIRTUAL CPU TIMER, A FLAG IS SET IN THE VMBLOK INDICATING
THAT THIS USER'S TIME SLICE HAS BEEN EXCEEDED. CONTROL IS
THEN PASSED TO THE DISPATCHER.
3. IF THE EXTERNAL INTERRUPT WAS DUE TO THE TIME OF DAY
CLOCK COMPARATOR, THE ACTIVE TIMER REQUEST QUEUE BLOCK
(TRQBLOK) IS STACKED FOR EXECUTION VIA DMKSTKIO. FOR A
UNIPROCESSOR SYSTEM THE CLOCK COMPARATOR IS RESET FROM THE
FIRST TRQBLOK ON THE QUEUE. FOR AN ATTACHED PROCESSOR SYSTEM
THE COMPARATOR IS RESET FROM THE FIRST TRQBLOK NOT ALREADY
ACTIVE ON THE OTHER PROCESSOR. CONTROL THEN TRANSFERS TO
THE DISPATCHER.
4. FOR EXTERNAL INTERRUPTS DUE TO EXTERNAL CALL, EMERGENCY
SIGNAL, TOD SYNC CHECK AND MALFUNCTION ALERT, CONTROL IS
TRANSFERRED TO DMKEXTSL.
THE DMKPSARX, DMKPSARS, DMKPSARR, AND DMKPSAID
ENTRY POINTS ARE DESCRIBED IN A FOLLOWING SECTION.