-- RTSymbolAccessImpl.mesa
-- Last Modified By Paul Rovner On February 16, 1983 10:14 am

DIRECTORY
        RTBasic USING[TypeIndex],
        RTOS USING[PrivateHeapZone, PermanentPageZone],
        RTSD USING[SD, sMapStiStd],
        RTSymbolDefs USING[nullHandle],
        RTTypesBasicPrivate USING[TMapStiStd, RMapStiStd, STDesc, SymbolTableIndex];

RTSymbolAccessImpl: MONITOR  -- protects MapStiStd
    IMPORTS RTOS
    EXPORTS RTTypesBasicPrivate

= BEGIN OPEN RTBasic, RTTypesBasicPrivate;

InitialSTIRangeSize: CARDINAL = 1000B;
lastSTIndex: TypeIndex _ 0;

MapStiStd: PUBLIC TMapStiStd;

TooManyTypes: ERROR = CODE;

FindSTI: PUBLIC ENTRY PROC[std: STDesc] RETURNS[i: SymbolTableIndex] =
 {ENABLE UNWIND => NULL; RETURN[DoFindSTI[std]]};
 
DoFindSTI: INTERNAL PROC[std: STDesc] RETURNS[i: SymbolTableIndex] =
INLINE
  { FOR i IN [1..lastSTIndex]
      DO IF MapStiStd[i].symbolsStamp = std.symbolsStamp
           THEN {IF std.bcd = NIL
                      OR std.sgi = MapStiStd[i].sgi
                     THEN {IF MapStiStd[i].sth = RTSymbolDefs.nullHandle
                               THEN MapStiStd[i].sth _ std.sth;
                              RETURN[i]}
                   };
     ENDLOOP;

    IF lastSTIndex = InitialSTIRangeSize - 1 THEN ERROR TooManyTypes;
    i _ lastSTIndex _ lastSTIndex + 1;
    MapStiStd[i] _ RTOS.PrivateHeapZone.NEW[STDesc _ std];
  };
    
-- START HERE
MapStiStd _ LOOPHOLE[RTOS.PermanentPageZone.NEW[RMapStiStd[InitialSTIRangeSize]]];

FOR i: CARDINAL IN [0..InitialSTIRangeSize) DO MapStiStd[i] _ NIL ENDLOOP;

LOOPHOLE[LONG[RTSD.SD + RTSD.sMapStiStd],
                     LONG POINTER TO LONG POINTER]^ _ MapStiStd;

END.