-- VolAllocMap.mesa (last edited by: Forrest on: March 7, 1980 8:43 PM)

DIRECTORY

FileInternal: FROM "FileInternal" USING [FilePtr, PageGroup],

LogicalVolume: FROM "LogicalVolume" USING [Handle, PageNumber];

VolAllocMap: DEFINITIONS =

BEGIN

FilePtr: TYPE = FileInternal.FilePtr;

GroupPtr: TYPE = POINTER TO FileInternal.PageGroup;

Handle: TYPE = LogicalVolume.Handle;

-- stoping operation (called from VolumeImpl, scavengeImpl)

Close: PROCEDURE [final: BOOLEAN];-- The sense of "final" is TRUE=flush Logical Volume/FALSE=stopping use for now

-- page group interfaces writing labels (called from FileImpl)

AllocPageGroup: PROCEDURE [vol: Handle, filePtr: FilePtr, groupPtr: GroupPtr, createFile: BOOLEAN]; -- allocates a group of pages and writes labels (group is a modifiable hint)

FreePageGroup: PROCEDURE [vol: Handle, filePtr: FilePtr, groupPtr: GroupPtr, deleteFile: BOOLEAN]; -- free a page group (deleting file if filePage=0 and deleteFile=TRUE);

-- Called from VolFileMapImpl to get new file map pages

AccessVAM: PROCEDURE [vol: Handle, volumePage: LogicalVolume.PageNumber, set, clear: BOOLEAN] RETURNS [busy: BOOLEAN]; -- set, clear or read one bit of vam, always returns the (previous) value;

END.

LOG

Time: April 13, 1978 3:32 PMBy: SPAction: Created file

Time: August 30, 1978 2:08 PM By: SPAction: use FilePtr’s

Time: August 28, 1979 5:35 PM By: ForrestAction: Changed Procs to use LogicalVolumeOps.Handle; took following stuff out of main body:

--File: FROM "File" USING [ID, Type],

-- page group interfaces writing labels

-- GetPageGroup: PROCEDURE [volume: Volume.ID, hint: FileInternal.PageGroup] RETURNS [FileInternal.PageGroup];

-- single page interfaces writing labels

-- CreateZPage: PROCEDURE [file: File.ID, type: File.Type] RETURNS [page: LogicalVolume.PageNumber];

-- FreeZPage: PROCEDURE [page: LogicalVolume.PageNumber, fileD: FileInternal.Descriptor];

-- CreateVPage: PROCEDURE [file: File.ID]RETURNS [LogicalVolume.PageNumber];

-- FreeVPage: PROCEDURE [file: File.ID, page: LogicalVolume.PageNumber];

-- low level bit map interface (no label writing)

-- GetBusy: PROCEDURE [volumePage: LogicalVolume.PageNumber] RETURNS [busy: BOOLEAN];

-- read the allocation state of page; TRUE if busy;

-- GetSetBusy: PROCEDURE [volumePage: LogicalVolume.PageNumber] RETURNS [busy: BOOLEAN];

-- set a page to busy and return its previous state (semaphore like lock here)

-- SetFree: PROCEDURE [volumePage: LogicalVolume.PageNumber];

-- free a page

-- GrabFirstFree: PROCEDURE [startPage: LogicalVolume.PageNumber] RETURNS [page: LogicalVolume.PageNumber];

-- find first free page and set it busy

Time: October 1, 1979 5:33 PM By: ForrestAction: took out Open:

Open: PROCEDURE [vol: LogicalVolume.Handle, init, rebuild: BOOLEAN];

Time: March 7, 1980 8:43 PM By: ForrestAction: Leaxically redefined types so would compile with new logicalVolume; take Handle out of close