Освобождение памяти

Code:

unit SnapForm;

interface

uses

Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,

StdCtrls;

type

TFormSnap = class(TForm)

   Memo1: TMemo;

private

   { Private declarations }

public

   { Public declarations }

end;

var

FormSnap: TFormSnap;

implementation

{$R *.DFM}

end.

unit DdhMMan;

interface

var

GetMemCount: Integer = 0;

FreeMemCount: Integer = 0;

ReallocMemCount: Integer = 0;

procedure SnapToFile(Filename: string);

implementation

uses

Windows, SysUtils, TypInfo;

var

OldMemMgr: TMemoryManager;

ObjList: array[1..10000] of Pointer;

FreeInList: Integer = 1;

procedure AddToList(P: Pointer);

begin

if FreeInList > High(ObjList) then

begin

   MessageBox(0, 'List full', 'MemMan', mb_ok);

   Exit;

end;

ObjList[FreeInList] := P;

Inc(FreeInList);

end;

procedure RemoveFromList(P: Pointer);

var

I: Integer;

begin

for I := 1to FreeInList - 1do

   if ObjList[I] = P then

   begin

     // remove element shifting down the others

     Dec(FreeInList);

     Move(ObjList[I + 1], ObjList[I],

       (FreeInList - I) * sizeof(pointer));

     Exit;

   end;

end;

procedure SnapToFile(Filename: string);

var

OutFile: TextFile;

I, CurrFree: Integer;

HeapStatus: THeapStatus;

Item: TObject;

ptd: PTypeData;

ppi: PPropInfo;

begin

AssignFile(OutFile, Filename);

try

   Rewrite(OutFile);

   CurrFree := FreeInList;

   // local heap status

   HeapStatus := GetHeapStatus;

   with HeapStatus do

   begin

     write(OutFile, 'Available address space: ');

     write(OutFile, TotalAddrSpace div1024);

     writeln(OutFile, ' Kbytes');

     write(OutFile, 'Uncommitted portion: ');

     write(OutFile, TotalUncommitted div1024);

     writeln(OutFile, ' Kbytes');

     write(OutFile, 'Committed portion: ');

     write(OutFile, TotalCommitted div1024);

     writeln(OutFile, ' Kbytes');

     write(OutFile, 'Free portion: ');

     write(OutFile, TotalFree div1024);

     writeln(OutFile, ' Kbytes');

     write(OutFile, 'Allocated portion: ');

     write(OutFile, TotalAllocated div1024);

     writeln(OutFile, ' Kbytes');

     write(OutFile, 'Address space load: ');

     write(OutFile, TotalAllocated div

       (TotalAddrSpace div100));

     writeln(OutFile, '%');

     write(OutFile, 'Total small free blocks: ');

     write(OutFile, FreeSmall div1024);

     writeln(OutFile, ' Kbytes');

     write(OutFile, 'Total big free blocks: ');

     write(OutFile, FreeBig div1024);

     writeln(OutFile, ' Kbytes');

     write(OutFile, 'Other unused blocks: ');

     write(OutFile, Unused div1024);

     writeln(OutFile, ' Kbytes');

     write(OutFile, 'Total overhead: ');

     write(OutFile, Overhead div1024);

     writeln(OutFile, ' Kbytes');

   end;

   // custom memory manager information

   writeln(OutFile); // free line

   write(OutFile, 'Memory objects: ');

   writeln(OutFile, CurrFree - 1);

   for I := 1to CurrFree - 1do

   begin

     write(OutFile, I);

     write(OutFile, ') ');

     write(OutFile, IntToHex(

       Cardinal(ObjList[I]), 16));

     write(OutFile, ' - ');

     try

       Item := TObject(ObjList[I]);

       // code not reliable

       { write (OutFile, Item.ClassName);

       write (OutFile, ' (');

       write (OutFile, IntToStr (Item.InstanceSize));

       write (OutFile, ' bytes)');}

       // type info technique

       if PTypeInfo(Item.ClassInfo).Kind <> tkClass then

         write(OutFile, 'Not an object')

       else

       begin

         ptd := GetTypeData(PTypeInfo(Item.ClassInfo));

         // name, if a component

         ppi := GetPropInfo(

           PTypeInfo(Item.ClassInfo), 'Name');

         if ppi <> nilthen

         begin

           write(OutFile, GetStrProp(Item, ppi));

           write(OutFile, ' :  ');

         end

         else

           write(OutFile, '(unnamed): ');

         write(OutFile, PTypeInfo(Item.ClassInfo).Name);

         write(OutFile, ' (');

         write(OutFile, ptd.ClassType.InstanceSize);

         write(OutFile, ' bytes)  -  In ');

         write(OutFile, ptd.UnitName);

         write(OutFile, '.dcu');

       end

     except

       on Exception do

         write(OutFile, 'Not an object');

     end;

     writeln(OutFile);

   end;

finally

   CloseFile(OutFile);

end;

end;

function NewGetMem(Size: Integer): Pointer;

begin

Inc(GetMemCount);

Result := OldMemMgr.GetMem(Size);

AddToList(Result);

end;

function NewFreeMem(P: Pointer): Integer;

begin

Inc(FreeMemCount);

Result := OldMemMgr.FreeMem(P);

RemoveFromList(P);

end;

function NewReallocMem(P: Pointer; Size: Integer): Pointer;

begin

Inc(ReallocMemCount);

Result := OldMemMgr.ReallocMem(P, Size);

// remove older object

RemoveFromList(P);

// add new one

AddToList(Result);

end;

const

NewMemMgr: TMemoryManager = (

   GetMem: NewGetMem;

   FreeMem: NewFreeMem;

   ReallocMem: NewReallocMem);

initialization

GetMemoryManager(OldMemMgr);

SetMemoryManager(NewMemMgr);

finalization

SetMemoryManager(OldMemMgr);

if (GetMemCount - FreeMemCount) <> 0then

   MessageBox(0, pChar('Objects left: ' +

     IntToStr(GetMemCount - FreeMemCount)),

     'MemManager', mb_ok);

end.

unit MemForm;

interface

uses

Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,

StdCtrls, ExtCtrls;

type

TForm1 = class(TForm)

   BtnCreateNil: TButton;

   BtnCreateOwner: TButton;

   BtnFreeLast: TButton;

   LblResult: TLabel;

   Btn100Strings: TButton;

   Bevel1: TBevel;

   BtnRefresh2: TButton;

   BtnSnap: TButton;

   SaveDialog1: TSaveDialog;

   procedure Button1Click(Sender: TObject);

   procedure BtnCreateNilClick(Sender: TObject);

   procedure BtnCreateOwnerClick(Sender: TObject);

   procedure BtnFreeLastClick(Sender: TObject);

   procedure Btn100StringsClick(Sender: TObject);

   procedure BtnRefresh2Click(Sender: TObject);

   procedure BtnSnapClick(Sender: TObject);

   procedure FormShow(Sender: TObject);

public

   b: TButton;

   procedure Refresh2;

end;

var

Form1: TForm1;

implementation

uses

DdhMMan, SnapForm;

{$R *.DFM}

procedure TForm1.Refresh2;

begin

LblResult.Caption := Format(

   'Allocated: %d'#13'Free: %d'#13'Existing: %d'#13'Re-allocated %d'      ,

   [GetMemCount, FreeMemCount,

   GetMemCount - FreeMemCount, ReallocMemCount]);

end;

procedure TForm1.Button1Click(Sender: TObject);

begin

Refresh2;

end;

procedure TForm1.BtnCreateNilClick(Sender: TObject);

begin

b := TButton.Create(nil);

Refresh2;

end;

procedure TForm1.BtnCreateOwnerClick(Sender: TObject);

begin

b := TButton.Create(self);

Refresh2;

end;

procedure TForm1.BtnFreeLastClick(Sender: TObject);

begin

if Assigned(b) then

begin

   b.Free;

   b := nil;

end;

Refresh2;

end;

procedure TForm1.Btn100StringsClick(Sender: TObject);

var

s1, s2: string;

I: Integer;

begin

s1 := 'hi';

s2 := Btn100Strings.Caption;

for I := 1to100do

   s1 := s1 + ': hello world';

Btn100Strings.Caption := s1;

s1 := s2;

Btn100Strings.Caption := s1;

Refresh2;

end;

procedure TForm1.BtnRefresh2Click(Sender: TObject);

begin

Refresh2;

end;

procedure TForm1.BtnSnapClick(Sender: TObject);

begin

if SaveDialog1.Execute then

begin

   SnapToFile(SaveDialog1.Filename);

   FormSnap.Memo1.Lines.LoadFromFile(

     SaveDialog1.Filename);

   FormSnap.Show;

end;

end;

procedure TForm1.FormShow(Sender: TObject);

begin

Refresh2;

end;

end.