<*+main*> (* This marks the main module of a program or library.            *)
<*heaplimit="0"*> (* Automatic heap size. Set other values to see effect.   *)

MODULE Test;

(* ------------------------------------------------------------------------
 * (C) 2011 by Alexander Iljin
 * ------------------------------------------------------------------------ *)

IMPORT oberonRTS, Out;

TYPE
   Chain = POINTER TO ChainDesc;
   ChainDesc = RECORD
      (* data size is 1 MByte minus pointer variable size *)
      data: ARRAY 1024 * 1024 DIV SIZE (LONGINT) - 1 OF LONGINT;
      next: Chain;
   END;

PROCEDURE CheckMaxHeapSize ();
(* Output the number of megabytes that were successfully allocated in heap.
 * The whole chain of allocated blocks stays rooted in the 'root' variable.
 * This test shows that it's impossible to allocate more than 1 Gb of heap
 * in XDS v2.51. The number goes up to 1066 Mb, while the expected limit would
 * be around 2 Gb on 32-bit systems. *)
VAR
   root, new: Chain;
   i: INTEGER;
BEGIN
   root := NIL;
   new := NIL;
   NEW (root);
   root.next := NIL;
   i := 1;
   Out.Int (i, 0);
   Out.Char (' ');
   LOOP
      NEW (new);
      new.next := root;
      root := new;
      INC (i);
      Out.Int (i, 0);
      Out.Char (' ');
   END;
END CheckMaxHeapSize;

PROCEDURE CheckCollector ();
(* The newly allocated blocks are not rooted in any global variable. The local
 * variable 'root' references only one block at a time, and oberonRTS.Collect
 * is called after every allocation, but still the heap is exhausted very
 * quickly (the numbers go to 1205 instead of 1066). This demonstrates a bug
 * in XDS memory management. *)
VAR
   root: Chain;
   i: INTEGER;
BEGIN
   root := NIL;
   NEW (root);
   root.next := NIL;
   i := 1;
   Out.Int (i, 0);
   Out.Char (' ');
   LOOP
      NEW (root.next);
      root := root.next; (* Note: the previous value of 'root' is lost, therefore can be garbage-collected. *)
      INC (i);
      Out.Int (i, 0);
      Out.Char (' ');
      oberonRTS.Collect;
   END;
END CheckCollector;

BEGIN
   ASSERT (SIZE (ChainDesc) = 1024*1024, 20);
   Out.Open;
   CheckMaxHeapSize;
   CheckCollector;
END Test.

<*+main*> (* This marks the main module of a program or library.            *)
<*heaplimit="0"*> (* Automatic heap size. Set other values to see effect.   *)

MODULE Test;

   IMPORT Out;
   
   VAR
      f: ARRAY 1000 OF ARRAY 100 OF REAL;
      
   PROCEDURE Do*;
   VAR
      i, j: INTEGER; sum: REAL;
   BEGIN
      FOR i := 0 TO LEN(f, 0) - 1 DO
         FOR j := 0 TO LEN(f, 1) - 1 DO
            f[i, j] := i * j / 100000
         END
      END;
      sum := 0;
      FOR i := 0 TO LEN(f) - 1 DO
         FOR j := 0 TO LEN(f, 1) - 1 DO
            sum := sum + f[i, j]
         END
      END;
      Out.Real(sum, 5); Out.Ln      
   END Do;

BEGIN
   Do
END Test.

#RTS: unhandled exception #5: whole overflow

File errinfo.$$$ created.

  EAX = 00020530  EBX = 7B8B0063
  ECX = 0000014B  EDX = 7B8B8001
  ESI = 7FFDF000  EDI = 0040C410
  EBP = 0032FE78  ESP = 0032FE1C
  EIP = 0040101F
 STACK:
  0032FE1C:  00007EB6 0040E020 7B8B3FF4 004010D5
  0032FE2C:  0040E020 0032FE48 001434F0 00000001
  0032FE3C:  001E8480 00000000 0040BBDE 00000001
  0032FE4C:  001434F0 00144B20 00000001 001434F0
  0032FE5C:  0032FEF0 0040C441 7B85F20C 7FFDF000
  0032FE6C:  7BC5036A 7B8B3FF4 7FFDF000 0032FEB8
  0032FE7C:  7B86048B 7FFDF000 0040C410 00000000
  0032FE8C:  00000000 00000000 00000000 00000000

f[i, j] := i * j / 100000

f[i, j] := LONG(i) * j / 100000