kbmMWGlobal in DLL hangs in when DLL is unloaded 5.23

[mrluigi2017]

Hi Kim,

We noticed that when the kbmMWGlobal is included in the uses of a DLL the application that uses the DLL will hang when it tries to unload it.

DLL Code:

library DllWithKbmMw;

{KbmMw source folder is in search path of project}

uses
  kbmMWGlobal;

{$R *.res}

begin
end.

Exe Code:

unit Main;

{

  Unloading DllWithKbmMw.dll is hanging.

}

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type

  TMainForm = class(TForm)
    LoadBtn: TButton;
    UnloadBtn: TButton;
    procedure LoadBtnClick(Sender: TObject);
    procedure UnloadBtnClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
    FDllH: THandle;
    procedure UpdateButtons;
  public
    { Public declarations }
  end;

var
  MainForm: TMainForm;

implementation

{$R *.dfm}

uses
  System.UITypes;

procedure TMainForm.FormCreate(Sender: TObject);
begin
  UpdateButtons;
end;

procedure TMainForm.LoadBtnClick(Sender: TObject);
var
  DllFn: string;
begin
  if FDllH=0 then
  begin
    DllFn:=IncludeTrailingPathDelimiter(ExtractFileDir(Application.ExeName))+
      'DllWithKbmMw.dll';
    FDllH:=LoadLibrary(PChar(DllFn));
    if FDllH=0 then
      raise Exception.Create('Error loading DLL: '+SysErrorMessage(GetLastError));
    UpdateButtons;
    MessageDlg('DLL loaded',TMsgDlgType.mtInformation,[mbOk],0);
  end;
end;

procedure TMainForm.UnloadBtnClick(Sender: TObject);
begin
  if FDllH<>0 then
  begin
    FreeLibrary(FDllH);//This will hang (in kbmMWFinalize)
    FDllH:=0;
    UpdateButtons;
    MessageDlg('DLL unloaded',TMsgDlgType.mtInformation,[mbOk],0);
  end;
end;

procedure TMainForm.UpdateButtons;
begin
  LoadBtn.Enabled:=FDllH=0;
  UnLoadBtn.Enabled:=FDllH<>0;
end;

end.

The problem is somewhere in the finalization of the unit, but we couldn’t pinpoint where it goes wrong exactly.

Could you please look into this!

Thanks in advance!

Kind regards Luigi

[kimbomadsen]

I think the problem has been solved in 5.24.00 by rewriting the kbmMWDependency package and cleaning up dependencies.

/Kim/C4D

[Author]

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