failed to create win32 control, error 87

[Michael Collier]

I get this error in my application when I reach a certain level of nested frames on windows NT.

failed to create win32 control, error 87

Here is an example that crashes, just paste the code into a new form and run..

Code: Pascal  [Select][+][-]

1. unit unit1;
2.  
3. {$mode objfpc}{$H+}
4.  
5. interface
6.  
7. uses
8.   Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, ComCtrls,
9.   ActnList, StdCtrls, ExtCtrls ;
10.  
11. type
12.  
13.   { Titem_frame }
14.  
15.   Titem_frame = class(TFrame)
16.   private
17.     { private declarations }
18.   public
19.     { public declarations }
20.     procedure nest ( a_count : integer ) ;
21.   end;
22.  
23.   { TForm1 }
24.  
25.   TForm1 = class(TForm)
26.     procedure FormShow(Sender: TObject);
27.   private
28.     { private declarations }
29.   public
30.     { public declarations }
31.   end;
32.  
33. var
34.   Form1: TForm1;
35.  
36. implementation
37.  
38. {$R *.lfm}
39.  
40. { Titem_frame }
41.  
42. procedure Titem_frame.nest(a_count: integer);
43. begin
44.   // quit if we hafe done all frames
45.   if (a_count = 0 ) then exit                    ;
46.  
47.   // create a nested frame
48.   with Titem_frame.Create( self )  do begin
49.     Name   := 'f'  + IntToStr(a_count)           ;
50.     Dec(a_count)                                 ;
51.     // set parant property - will crash here..
52.     Parent := self                               ;
53.     //
54.     Align  := alClient                           ;
55.     // recursive..
56.     nest(a_count)                                ;
57.   end;
58. end;
59.  
60. { TForm1 }
61.  
62. procedure TForm1.FormShow(Sender: TObject);
63. begin
64.   with Titem_frame.Create ( self ) do begin
65.     Name   :='frame1'                          ;
66.     Parent := self                             ;
67.     Align  := alClient                         ;
68.     // Crashes at around 46 on my machine.
69.     // In my real application which has more controls it seems to crash much lower..
70.     nest(50)                                   ;
71.   end;
72. end;
73.  
74.  
75. end.
76.  
77.  

It crashes into line 244 of Win32WSControls

Code: Pascal  [Select][+][-]

1. raise Exception.Create('Failed to create win32 control, error: ' + IntToStr(AErrorCode) + ' : ' + GetLastErrorText(AErrorCode));
2.  

[Cyrax]

You are running out of USER and/or GDI handles. That's why you are getting that error.

Are you really developing under old NT series? Not Windows 2000, XP, Vista+?

[Thaddy]

That makes sense, from win2000 onwards it is very unlikely that you see that error....
Btw: FPC doesn't support NT4 or worse.

Way back:
You receive a "System error 87 has occurred.
RESOLUTION
To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the individual software update. For information on obtaining the latest service pack, please go to:

    152734 How to obtain the latest Windows NT 4.0 service pack

For information on obtaining the individual software update, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:
http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

[Thaddy]

Time to upgrade to ReactOS 

[Michael Collier]

Oops, I meant windows XP (service pack 3), the same error occurs on windows vista (service pack 2). I keep projects on ubuntu server and compile from a range of machines over a samba. Sorry for the confusion, my bad.

Are you certain it is resource related, I can create 200 times as many frames if I don't nest them.

Here is similar code creating twice as many frames but using the main form as parent.

Code: Pascal  [Select][+][-]

1. procedure TForm1.ToolButton1Click(Sender: TObject);
2. var i : integer ;
3. begin
4.   for i := 0 to 1000 do begin
5.     with Titem_frame.Create(self) do begin
6.       name := 'f' + IntToStr(i);
7.       parent  := self ;
8.       Align:= alTop;
9.     end;
10.   end;
11. end;  

[balazsszekely]

@Michael Collier
With some xp related reference:
https://blogs.msdn.microsoft.com/oldnewthing/20031218-00/?p=41453

[Thaddy]

Frames should never cause that because they are design time only.
Do you have some little project that replicates the issue, because I can't replicate it.

[Cyrax]

Frames should never cause that because they are design time only.
Do you have some little project that replicates the issue, because I can't replicate it.

Wrong. Frames and other controls can be created at run time, too.

[balazsszekely]

@Thaddy
Checked with Window Detective(see screenshot). From the operating system's perspective, the frame is considered a window, so nesting a frame into a form, is still nesting a window in window. Multiple nesting will eventually lead to the nesting limit exception(see the link in my previous post).

[Thaddy]

Frames should never cause that because they are design time only.
Do you have some little project that replicates the issue, because I can't replicate it.

Wrong. Frames and other controls can be created at run time, too.

According to the patent! from Allen Bauer et. al. they shouldn't
That's a design flaw in Lazarus if it is really accepted to create frames at run-time.
By design  it is a design-time container and not something that could be used at run-time.
Dead give-away: the patent is about not taking up any resources.

[edit]
So you mean to tell me that only KOL implements it correctly

[Thaddy]

@Michael Collier:
Who is self? You mean form.self or control.self? Don't use with, plz. I can crash anything with with.

You need some self esteem to write code like that .

[balazsszekely]

@Thaddy
It was always possible to create frames at runtime(both delphi and lazarus).

[Thaddy]

@Thaddy
It was always possible to create frames at runtime(both delphi and lazarus).

I know, I checked, it's a bug....

Oh, well, so may patents not implemented correctly including mine(just 1)  KOL  uses the design time only paradigm to the full.

[Michael Collier]

Sorry about use of create/with, my real application doesn't use that method, just tried to keep snippet small for posting but probably made things worse..will try to provide better example after a bit more investigation into this, thanks for help

[balazsszekely]

@Thaddy
I really don't want to insist on this issue, but in my opinion creating frames at runtime is a perfectly valid thing, although I do agree, the main advantage of the frame is that you can create multiple instances of it at design time.