Project1.dpr

program Project1;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  FastMM4,
  System.SysUtils,
  System.Classes;

type
  TRawMessageString = record
   private
     fStringData : RawByteString;
   public
     procedure LoadFromStream(const aStream : TBytesStream; const aLength : Integer);
     procedure SaveToStream(const aStream : TBytesStream);
  end;

procedure TRawMessageString.LoadFromStream(const aStream : TBytesStream; const aLength : Integer);
begin
  SetLength(fStringData, aLength);
  aStream.ReadBuffer(fStringData[1], aLength);
end;

procedure TRawMessageString.SaveToStream(const aStream : TBytesStream);
var
  k: Integer;
begin
  k := System.Length(fStringData);
  if k > 0 then
  begin
    aStream.Write(fStringData[1], k); // <- FastMM4 pointed memory leak in this line
  end;
end;

function GetMessage() : TRawMessageString;
var
  i: Integer;
  lStream: TBytesStream;
  b: Byte;
begin
  lStream := TBytesStream.Create();
  try
  //create fake message
  for i := 0 to 99999 do
  begin
    b := Random(25) + 65;
    lStream.Write(b, 1);
  end;
  lStream.Position := 0;
  Result.LoadFromStream(lStream, lStream.Size);
  finally
  lStream.Free;
  end;
end;

procedure InternalSendMessage(const aMessage : TRawMessageString);
var
  lStream : TBytesStream;
begin
  lStream := TBytesStream.Create();
  try
  aMessage.SaveToStream(lStream);
  finally
  lStream.Free;
  end;
end;

procedure SendMessage(); overload;
var
  lMsg: TRawMessageString;
begin
  lMsg := GetMessage();
  InternalSendMessage(lMsg);
end;


begin
  try
    SendMessage;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.