[SzakiLaci]

Please help me, because I’m going crazy and loosing my customer’s trust day by day because of this strange error. 🙁
It appeared since ca 2-3 weeks ago, everything worked fine for years before that.
And I did not change any setup or components since min. 2 years, the only difference is that my program is starting 5 different background threads instead of 4.
(But that thread has nothing to do with AC, only using TUIBDatabase SQL and OverbyteIcs https components, and a thread safe memory-logging system, which also has nothing to do with AC, because none of those are interacting directly with any desktop items.)

If I search for this error on this forum, I can find 5 other mentioning about similar topics, but those were very early versions.

https://www.alphaskins.com/forum/?action=bbp-search-request&bbp_search=GDIError

The Error:
– Appears after using the program several hours long, so I can not reproduce it on my developer PC.
– Appears both on win7 and Win10
– both on 32 bit / 64 bit. (my exe is always 32bit)
– with different VGA cards and drivers too
– Appears on different forms and actions randomly (will copy more reports to show). But mostly if Form.Show happens.
– it is impossible to continue the program, it is stuck in a loop, no try-except can handle it properly.
– the user can only force-close and restart the whole EXE, while loosing data not yet saved.

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[SzakiLaci]

I have a suspicion that this error has to do with Thread safety somehow.

The “new” background thread I mentioned gives “out of memory” messages too, while the program’s mem-usage is under 150MB, and the OS has min. 1GB+ free RAM.
(As You can see from attached bugreports. That thread is called: “HatterNTAK_szal”)

I see that from my own LOGs:
When a TUIBQuery component tries to load max 64 tiny rows from database. (Which is very small amount of data, max 1-2 Kbytes.) It can open that table, so the try..except writes: “out of memory” error to my LOG file.
Maybe it has nothing to do with it, but that’s my only “similar error” starting point so far.

Also checked the VGA-memory usage, no problems there either.

Worth to mention that I’m using FastMM4 latest module, so that should be stable too.
( Of course with {$define AssumeMultiThreaded} enabled )

• This reply was modified 1 year, 4 months ago by SzakiLaci.

[SzakiLaci]

Sorry, forgot to tell: I’m using 2019.05 version: v14.29

  object sSkinManager1: TsSkinManager
    SkinsFilter = [sfiInternal]
    Effects.AllowAnimation = False
    AnimEffects.DialogShow.Active = False
    AnimEffects.FormShow.Active = False
    AnimEffects.FormHide.Active = False
    AnimEffects.DialogHide.Active = False
    AnimEffects.Minimizing.Active = False
    AnimEffects.PageChange.Active = False
    AnimEffects.SkinChanging.Active = False
    AnimEffects.SkinChanging.Time = 0
    AnimEffects.SkinChanging.Mode = atDropDown
    ButtonsOptions.OldGlyphsMode = True
    ButtonsOptions.ModalButtonsColoring = []
    Active = False
    CommonSections.Strings = (
      '[PN_ATLATSZO]'
      'TRANSPARENCY=100'
      ''
...
    UseCache = False
    Bitmap = {}

  object sSkinProvider1: TsSkinProvider
    AllowAnimation = False
    AllowBlendOnMoving = False
    AllowSkin3rdParty = False
    ScreenSnap = True
    AllowExtBorders = False
    UseGlobalColor = False
    AddedTitle.Font.Charset = EASTEUROPE_CHARSET
    AddedTitle.Font.Color = clNone
    AddedTitle.Font.Height = -11
    AddedTitle.Font.Name = 'Arial'
    AddedTitle.Font.Style = []
    SkinData.SkinSection = 'FORM'
...

I guess first thing You will recommend to upgrade it, but I’m afraid something similar may happen, as last time. (Worked several month long to correct all the anomalies.)

[Lasse]

I recommend asking ChatGPT e.g. “How to track GDIError (EOutOfResources = out of memory) errors in Delphi?”. It gives an excellent answer.

I bet my money on creating GDI objects and not deleting them somewhere. I have seen that thousand times.

[Lasse]

That said… for example find “CreatePen” from AlphaSkins source and you will find a leak in sGraphUtils.pas:

SelectObject(DC, CreatePen(PS_SOLID, 2, clWhite));

That will create a pen and it is never deleted. The code should be like:

var
  LPen: HPEN;
begin
  LPen := CreatePen(...);
  try
    // Use the pen for drawing
  finally
    DeleteObject(LPen); // Release the GDI pen object
  end;
end;

• This reply was modified 1 year, 4 months ago by Lasse.

[SzakiLaci]

Thank you very much!
I will change that.

Can You please add a few more examples, what else to search for, not just “CreatePen” ?

And yes, I’ve also noticed there are still some memory leaks in the code.
But it seems it has improved a lot since the 2019 version.
noticed Serge forgets to put:
inherited Destroy;
to the end of the Destroy procedures after all other “clearings”, instead of the beginning.

2.
Do you know if it’s enough to FreeAndNil(FTextTimer) a timer component, instead of first stopping it by :
FTextTimer.Enabled := False;
?
(like he does at: destructor TacCustomCombo.Destroy; )

[Lasse]

You can check what objects can be created for SelectObject.

– Bitmap: CreateBitmap, CreateBitmapIndirect, CreateCompatibleBitmap, CreateDIBitmap, CreateDIBSection
– Brush: CreateBrushIndirect, CreateDIBPatternBrush, CreateDIBPatternBrushPt, CreateHatchBrush, CreatePatternBrush, CreateSolidBrush
– Font: CreateFont, CreateFontIndirect
– Pen: CreatePen, CreatePenIndirect
– Region: CombineRgn, CreateEllipticRgn, CreateEllipticRgnIndirect, CreatePolygonRgn, CreateRectRgn, CreateRectRgnIndirect

I have mostly seen CreatePen and CreateBrush leaks. But there are also many other kind of traps to fall into. The worst I know is SHGetFileInfo where you need to destroy the icon handle, if you are not using it. Usually you’re only interested in icon index.

For example

function GetIconIndex(const AFilename: string; const AFileAttributes: Cardinal; const AMoreFlags: Cardinal): Integer;
var
  LFileInfo: TSHFileInfo;
begin
  if SHGetFileInfo(PChar(AFilename), AFileAttributes, LFileInfo, SizeOf(TSHFileInfo), SHGFI_SYSICONINDEX or SHGFI_SMALLICON or
    SHGFI_ICON or AMoreFlags) = 0 then
    Result := -1
  else
  begin
    Result := LFileInfo.iIcon;
    { Important! Destroy the icon, we are only using the index. }
    DestroyIcon(LFileInfo.hIcon);
  end;
end;

[Lasse]

Yes, FreeAndNil(FTextTimer) is ok.

TTimer destroy will disable it.

destructor TTimer.Destroy;
begin
  FEnabled := False;
  ...

[SzakiLaci]

After I’ve upgraded to latest version=17.01
this error seems to disappeared. (But not tested enough yet… so it’s not final.)

But, other huge errors started to appear, like:
sendtoback-brings-the-form-to-foreground

[chris2023]

Solution

• This reply was modified 1 year, 4 months ago by chris2023.

[SzakiLaci]

Dear Chris2023,
Please delete your post.
This is not a solution.

[SzakiLaci]

SzakiLaci wrote:

After I’ve upgraded to latest version=17.01
this error seems to disappeared. (But not tested enough yet… so it’s not final.)

I take it back 🙁

It has turned out: the same error can still happen with the latest version too.
While it’s rare compared to the old one.

So I will put back the 2019 version, it was much much more stable and will enhance the AC code with the recommended try…finally and some try..except lines.

[Author]

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