Type ASSEMBLE
Source Lines : 317
Fixes Applied : 0
Most Recent Version : Thursday, December 7, 1978
Last Fix ID : [Unmodified]
Module
DMTASY
Function
DMTASY IS A SUPERVISOR SERVICE ROUTINE MODULE
WHICH INITIATES AND TERMINATES ASYNCHRONOUS EXIT
REQUESTS FOR TASK PROGRAMS. ASYNCHRONOUS EXIT
REQUESTS FOR ASYNCHRONOUS I/O INTERRUPT, EXTERNAL
INTERRUPT, AND ALERT EXIT REQUESTS ARE HANDLED BY
THIS ROUTINE.
Attributes
REUSABLE
Operation
DMTASY BEGINS BY UNCONDITIONALLY SUSPENDING THE
CALLING TASK'S EXECUTION WITH A FREEZE SVC. FOR AN
INITIATE EXIT REQUEST, THE APPROPRIATE QUEUE IS
SCANNED FOR AN EXISTING SIMILAR REQUEST FOR THE SAME
TASK. IF NONE IS FOUND, A SUPERVISOR STATUS QUEUE
ELEMENT IS GOTTEN BY A CALL TO DMTQRQ, THE NEW EXIT
ELEMENT IS BUILT FROM THE SUPPLIED INFORMATION, AND
IT IS QUEUED ON THE APPROPRIATE CHAIN.
FOR CLOCK COMPARATOR REQUESTS, THE NEW REQUEST IS
QUEUED IN THE APPROPRIATE PLACE IN THE QUEUE. THE
EXTERNAL QUEUE IS ORDERED IN THE FOLLOWING WAY:
1. CLOCK COMPARATOR INTERRUPTS IN ASCENDING CLOCK VALUE
ORDER.
2. ALL OTHER EXTERNAL REQUESTS.
IF THE NEW REQUEST IS NOW THE LOWEST CLOCK REQUEST,
ITS CLOCK VALUE IS SET IN THE CLOCK COMPARATOR.
IF AN ELEMENT IS FOUND AND A TERMINATE REQUEST IS BEING
MADE, THE ELEMENT IS DEQUEUED AND RETURNED TO THE FREEQ.
IF THE RETURNED ELEMENT REPRESENTS THE ACTIVE CLOCK
COMPARATOR, THE CLOCK COMPARATOR IS SET TO ALL F'S.
NOTE:
THE EXTERNAL INTERRUPT QUEUE IS MAINTAINED IN THE
FOLLOWING ORDER:
. CLOCK COMPARATOR REQUESTS IN ASCENDING CLOCK ORDER.
THE FIRST CLOCK COMPARATOR ENTRY REPRESENTS THE
CLOCK VALUE WHICH HAS BEEN SET (UNLESS NONE HAS BEEN
REQUESTED, IN WHICH CASE THE CLOCK COMPARATOR IS FF'S)
. ALL OTHER EXTERNAL INTERRUPT REQUESTS IN ANY ORDER.
CLOCK COMPARATOR EXIT REQUESTS ARE INITIATED BY THIS
ROUTINE. THEY ARE TERMINATED BY EITHER A TERMINATE
REQUEST TO THIS ROUTINE OR BY THE OCCURENCE OF THE
INTERRUPT.
Calls to Other Routines
DMTQRQ - TO RESERVE AND RELEASE SUP QUEUE ELEMENTS