Type ASSEMBLE
Source Lines : 2,181
Fixes Applied : 1
Most Recent Version : Tuesday, December 12, 1978
Last Fix ID : [R11833DS]
Module
DMSFRE (FREE AND FRET)
Function
MANAGEMENT OF FREE STORAGE.
Attributes
NUCLEUS RESIDENT, RE-ENTRANT
Operation
DMSFREB -- ALLOCATES OR RELEASES A BLOCK OF STORAGE DEPENDING
UPON THE CODE IN NUCON LOCATION 'CODE203'. THE EXACT
METHOD OF OPERATION IS DESCRIBED IN THE PLM, IN THE
SECTION ON FREE STORAGE MANAGEMENT.
DMSFREES -- THE SIZE IS LOADED FROM THE PLIST, AND A DMSFREE
MACRO IS EXECUTED. UPON RETURN, THE ADDRESS OF THE
ALLOCATED BLOCK IS STORED INTO THE PLIST.
DMSFRETS -- THE SIZE AND ADDRESS OF THE BLOCK TO BE RELEASED
ARE LOADED FROM THE PLIST, AND A DMSFRET MACRO IS
EXECUTED.
DMSFREEX -- A DMSFREE MACRO IS EXECUTED.
DMSFRETX -- A DMSFRET MACRO IS EXECUTED.
DMSFRES -- THE FOLLOWING SERVICE ROUTINES ARE EXECUTED:
CKON: TURN ON FLAG WHICH CAUSES 'CHECK' TO BE EXECUTED WITH
EACH CALL TO DMSFRE.
CKOFF: TURN OFF THIS FLAG.
INIT1: FIRST DMSFRE INITIALIZATION ROUTINE. THIS ROUTINE
INITIALIZES FREE STORAGE IN A TEMPORARY WAY, SO THAT
THE SYSTEM DISK CAN BE LOGGED IN.
INIT2: SECOND DMSFRE INITIALIZATION ROUTINE. THIS ROUTINE
IS CALLED AFTER THE SIZE OF VIRTUAL MEMORY IS KNOWN,
TO PREPARE STORAGE FOR THE USUAL ACTIVITY IN FREE
STORAGE ALLOCATION. ANY HIGH-CORE POINTERS ARE CLEARED,
THE 'FREETAB' FREE STORAGE TABLE IS ALLOCATED (THIS
TABLE CONTAINS ONE BYTE FOR EACH PAGE OF VIRTUAL
MEMORY, WHICH INDICATES THE USE OF THAT PAGE), ALL
STORAGE KEYS ARE INITIALIZED, AND THE CHAINS ARE
CLEANED UP.
CHECKS: CAUSE ALL CHAINS TO BE CHECKED FOR VALIDITY.
UREC: RECOVERY ROUTINE CALLED BY DMSABN. ALL USER FREE
STORAGE BLOCKS ARE RELEASED.
CALOC: COMPUTATION ROUTINE CALLED BY DMSABN. THIS ROUTINE
COMPUTES THE SIZE OF ALLOCATED STORAGE.
Calls to Other Routines
DMSERR -- TO TYPE OUT ERROR MESSAGES