-- FilerExceptionImpl.mesa (last edited by: Forrest on: April 28, 1980 9:29 AM) --

DIRECTORY

FilePageTransfer: FROM "FilePageTransfer" USING [Request],

FilerException: FROM "FilerException",

FilerPrograms: FROM "FilerPrograms",

Frame: FROM "Frame" USING [Alloc, Free],

RuntimeInternal: FROM "RuntimeInternal" USING [MakeFsi];

--Process: FROM "Process" USING [DisableAborts];

FilerExceptionImpl: MONITOR
IMPORTS Frame, RuntimeInternal --, Process
EXPORTS FilerException, FilerPrograms =

BEGIN

FE: TYPE = RECORD [pFEPrev: PFE, req: FilePageTransfer.Request];

fsiFE: CARDINAL = RuntimeInternal.MakeFsi[SIZE[FE]];

PFE: TYPE = POINTER TO FE;

pFELast: PFE ← NIL; -- points to last of fifo queue of exception reports

report: CONDITION;

-- Waits for a Filer exception to occur

Await: PUBLIC ENTRY PROCEDURE RETURNS [rwReq: FilePageTransfer.Request] =

BEGIN

pFE, pFENext: PFE;

WHILE pFELast=NIL DO WAIT report ENDLOOP;

-- Remove first report from queue and return it

FOR pFE ← pFELast, pFE.pFEPrev WHILE pFE.pFEPrev~=NIL DO pFENext ← pFE; ENDLOOP;

rwReq ← pFE.req;

IF pFE=pFELast THEN pFELast ← NIL ELSE pFENext.pFEPrev ← NIL;

Frame.Free[pFE]

END;

-- Add report to end of queue

Report: PUBLIC ENTRY PROCEDURE [rwReq: FilePageTransfer.Request] =

BEGIN

pFE: PFE = LOOPHOLE[Frame.Alloc[fsiFE], PFE];

pFE↑ ← [pFELast, rwReq];

pFELast ← pFE;

NOTIFY report

END;

--Process.DisableAborts[@report];

END.

LOG

Time: February 27, 1979 9:51 PMBy: RedellAction: Created file from old CacheMissImpl.mesa

Time: November 16, 1979 2:24 PMBy: ForrestAction: Changed to allocate Frames for storage

Time: April 28, 1980 9:26 AMBy: ForrestAction: FrameOps => Frame.

Time: timeStampBy: yourNameAction: shortDescription