-- Swapper>SwapTask.mesa (last edited by Gobbel on November 26, 1979 5:21 PM)

DIRECTORY

CachedRegion: FROM "CachedRegion" USING [Desc],

PageMap: FROM "PageMap" USING [Flags],

VM: FROM "VM" USING [Interval, PageCount, PageNumber];

SwapTask: DEFINITIONS =

BEGIN

State: TYPE = RECORD [

next: PRIVATE PState,-- next in swapTaskList.

swapInterval: VM.Interval,-- the interval to be swapped.

flags: PageMap.Flags,-- of region when swap is finished.

bufferPage: VM.PageNumber,-- start of i/o buffer.

countRemaining: VM.PageCount,-- number of pages not yet transferred.

region: CachedRegion.Desc];-- desc to be checked-in upon completion.

PState: PRIVATE TYPE = POINTER TO State;

Fork: PROCEDURE [swapInterval: VM.Interval, flags: PageMap.Flags, bufferPage: VM.PageNumber, swapCount: VM.PageCount, region: CachedRegion.Desc]

RETURNS [forked: BOOLEAN];

-- Stores a State describing the swapping to be done on a swap unit of a region. If the operation is vacuous, no State is stored and forked=FALSE is returned.

Advance: PROCEDURE [interval: VM.Interval] RETURNS [state: State];

-- Returns the State which contains interval.page. If State.countRemaining=0, the State is also deleted.

END.

LOG

Time: During March 1978By: McJonesAction: Created file

Time: June 29, 1978 5:50 PMBy: McJonesAction: Moved PageCount, PageNumber to VM

Time: September 5, 1978 2:44 PMBy: RedellAction: Replaced over-complex ’Action’ record with ’flags’ field in swaptask ’State’ record. Added ’swapCount’ argument and ’forked’ result to Fork.

Time: September 20, 1979 9:45 AMBy: KnutsenAction: Added swapInterval. Added documentation.

Time: November 26, 1979 12:17 PMBy: GobbelAction: Added count to Advance.