(* ========================================================= *)
(* Library module for Gardens Point Modula                   *)
(* ========================================================= *)
(* 09-Jul-92  jrh  Original version                          *)
(* 20-Jul-92  jrh  Remove WriteSummary                       *)
(* ========================================================= *)

FOREIGN DEFINITION MODULE StorageStats;


  PROCEDURE GetSummary (VAR current, maximum,
  			    heapTop, largest : CARDINAL);
  (* precondition  : TRUE				     *)
  (* postcondition : storage summary data returned:	     *)
  (*							     *)
  (* current is the current total allocated (use this to     *)
  (*	check for gradual exhaustion of memory due to	     *)
  (*	failure to DEALLOCATE)				     *)
  (* maximum is the maximum total allocated since the	     *)
  (*	program started (use this to see how close you are   *)
  (*	to running out)					     *)
  (* heapTop is the top of the part of the space between the *)
  (*	top of your program and the '640K limit' actually    *)
  (*	used by your program (compare this with maximum	     *)
  (*	to see the degree of fragmentation)		     *)
  (* largest is the largest block on the free list - ie a    *)
  (*	block you have used and DEALLOCATEd but which has    *)
  (*	not been re-used or only partly re-used (thus	     *)
  (*	available memory comprises this block, an	     *)
  (*	unspecified number of smaller ones also on the free  *)
  (*	list, with the total size of the free list equal to  *)
  (*	maximum-current, plus the contiguous block from	     *)
  (*	heapTop to 640K)				     *)


(* ----------------------------------------------------------------------
   Typical usage of GetSummary is as follows. This procedure is not
   included in StorageStats because in the current implementation
   StorageStats code is in STORAGE.OBJ, so that any program using
   dynamic Storage would also have to link INOUT.OBJ.

FROM InOut IMPORT WriteString, WriteCard, WriteHex, WriteLn;

PROCEDURE WriteSummary;
  (* precondition  : TRUE                                    *)
  (* postcondition : storage use summary as described in     *)
  (*                 GetSummary has been written to standard *)
  (*		     output; format is one line per item,    *)
  (*		     in both decimal and hexadecimal         *)

VAR
  current, maximum, heapTop, largest : CARDINAL;

BEGIN
  GetSummary (current, maximum, heapTop, largest);
  WriteString ("Currently allocated:   ");
  WriteCard (current,12); WriteString ("(dec)");
  WriteHex (current,10); WriteString ("(hex)");
  WriteLn;
  WriteString ("Maximum allocated was: ");
  WriteCard (maximum,12); WriteString ("(dec)");
  WriteHex (maximum,10); WriteString ("(hex)");
  WriteLn;
  WriteString ("Heap top is:           ");
  WriteCard (heapTop,12); WriteString ("(dec)");
  WriteHex (heapTop,10); WriteString ("(hex)");
  WriteLn;
  WriteString ("Size of largest free:  ");
  WriteCard (largest,12); WriteString ("(dec)");
  WriteHex (largest,10); WriteString ("(hex)");
  WriteLn;
END WriteSummary;
---------------------------------------------------------------------- *)

END StorageStats.