DMKTDK Abstract

Type ASSEMBLE
Source Lines : 489
Fixes Applied : 2
Most Recent Version : Thursday, December 7, 1978
Last Fix ID : [HRC106DK]

Module

       DMKTDK

Function

       TO ALLOCATE CYLINDERS OF TDISK SPACE FROM CP OWNED VOLUMES

Attributes

       REENTRANT, PAGEABLE, CALLED VIA SVC

Operation

       1. LOCATE AN RDEVBLOK FOR A DEVICE CONTAINING A VOLUME OF
          THE DESIRED TYPE; IF NONE CAN BE FOUND RETURN A VALUE OF
          ZERO IN GPR8 AND EXIT
       2. LOCATE AN ALOCBLOK FOR TDISK SPACE ON THE ALLOCATION CHAIN
          FROM THE RDEVBLOK; IF NONE CAN BE FOUND GO TO STEP 1;
          OTHERWISE, CONTINUE
       3. LOCATE AN UNALLOCATED CYLINDER ON THE ALLOCATION MAP AND
          VERIFY THAT ENOUGH CONTIGUOUS CYLINDERS EXIST TO SATISFY
          THE REQUEST; IF ENOUGH CYLINDERS ARE NOT AVAILABLE GO TO
          STEP 2; OTHERWISE, CONTINUE
       4. MARK THE CYLINDERS ALLOCATED IN THE ALLOCATION MAP AND
          ERASE TRACK ZERO OF THIS EXTENT TO ZEROES. RETURN THE
          ADDRESS OF THE FIRST CYLINDER ALLOCATED TO THE CALLER
          IN GPR1 AND THE ADDRESS OF THE RDEVBLOK IN GPR8; THEN,
          EXIT TO THE CALLER.

Calls to Other Routines

       DMKIOSQR