-- Store>FilePageTransfer.mesa (February 11, 1981 by Knutsen)

DIRECTORY

Environment USING [PageCount, PageNumber],

File USING [Capability, PageNumber],

FileInternal USING [Operation],

VM USING [Interval];

FilePageTransfer: DEFINITIONS =

BEGIN

Request: TYPE = RECORD[

file: File.Capability,

filePage: File.PageNumber,

memoryPage: Environment.PageNumber,

count: Environment.PageCount,

promise: BOOLEAN ← FALSE, -- should Initiate MStore.Promise the page groups as they are actually initiated?

opSpecific: SELECT operation: Operation FROM

read => [priorityPage: File.PageNumber],

write => NULL,

ENDCASE];

Operation: TYPE = FileInternal.Operation[read..write];

Initiate: PROCEDURE [req: Request];

-- Starts an I/O operation on a block of pages. If req.promise=TRUE, calls MStore.Promise for each page group within the block just before it is actually initiated.

Wait: PROCEDURE RETURNS [VM.Interval];

-- Waits until the completion of the transfer of any page group of any previously Initiate’ed request.

END.

LOG

March 10, 1978 3:09 PMRedellCreated file

September 5, 1979 3:08 PMMcJonesAR1593: Added countInitiated result to Initiate, promise to Request

September 18, 1979 4:59 PMKnutsenImproved documentation.

November 26, 1979 12:24 PMGobbelWait now returns VM.Interval instead of PageNumber.

February 11, 1981 3:51 PMKnutsenInitiate no longer returns countInitialted. Initiate will promise the memory itself.