Re: [Lazarus] SIGSEGV with Debug only
Am 31.03.2012 03:57, schrieb waldo kitty: On 3/30/2012 04:28, Martin Schreiber wrote: Am 30.03.2012 02:06, schrieb Daniel Simoes de Ameida: I'm using Debug Info as Auto (-g) and Display Line numbers (-gl), Heaptrace Unit is also active (-gh)in Debug mode ... Any hints ? Heaptrace fills freed memory with garbage. CurAnchorSide probably is in a object which already has been destroyed. ewww :( in my ancient mind, it would be better to fill with null for possible checks but then again ;) :P Actually it is $F0. The purpose is that $F0F0F0F0 as pointer should throw a SIGSEGV. Another heaptrace signature is $DEADBEEF. If you see this address in a pointer of your data structs there probably is something wrong. ;-) Martin Schreiber -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] SIGSEGV with Debug only
A not initialized (running wild) pointer can behave like this. -Michael -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] SIGSEGV with Debug only
Am 30.03.2012 02:06, schrieb Daniel Simoes de Ameida: Hi All I have a strange issue... I'm currently using Lazarus 0.9.31 (update from SVN) with FPC 2.6.0 When I compile my application with debug information, I always get a SIGSEGV when closing one of my forms,on line 4805 of control.inc This Image http://imagebin.org/205899shows the error. However, when compiling without debug information, the errors do not occur (better this way) .. I'm using Debug Info as Auto (-g) and Display Line numbers (-gl), Heaptrace Unit is also active (-gh)in Debug mode ... Any hints ? Heaptrace fills freed memory with garbage. CurAnchorSide probably is in a object which already has been destroyed. Martin -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] SIGSEGV with Debug only
Bingo... Is the HeapTrace.. I just removed HeapTrace Unit from Linking and the problem has gone... Thanks Martin []s Daniel Conheça o Projeto ACBr - Automaçao Comercial Brasil DJSystem a Loja Patrocinadora do ACBr De: Martin Schreiber mse00...@gmail.com Para: lazarus@lists.lazarus.freepascal.org Enviadas: Sexta-feira, 30 de Março de 2012 5:28 Assunto: Re: [Lazarus] SIGSEGV with Debug only Am 30.03.2012 02:06, schrieb Daniel Simoes de Ameida: Hi All I have a strange issue... I'm currently using Lazarus 0.9.31 (update from SVN) with FPC 2.6.0 When I compile my application with debug information, I always get a SIGSEGV when closing one of my forms,on line 4805 of control.inc This Image http://imagebin.org/205899shows the error. However, when compiling without debug information, the errors do not occur (better this way) .. I'm using Debug Info as Auto (-g) and Display Line numbers (-gl), Heaptrace Unit is also active (-gh)in Debug mode ... Any hints ? Heaptrace fills freed memory with garbage. CurAnchorSide probably is in a object which already has been destroyed. Martin -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] SIGSEGV with Debug only
Hello Lazarus-List, Friday, March 30, 2012, 5:11:07 PM, you wrote: DSdA Bingo... DSdA Is the HeapTrace.. I just removed HeapTrace Unit from DSdA Linking and the problem has gone... Removing heaptrace hide the error not fix the bug. The heaptrace is showing you a bug that otherwise you will not be aware of it in most situations like: var a: TSomething; begin a:=TSomething.Create; a.Method; a.Free; a.Method; //This is a bug that will be showed by heaptrace. end; -- Best regards, José -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] SIGSEGV with Debug only
On 30/03/2012 16:11, Daniel Simoes de Ameida wrote: Bingo... Is the HeapTrace.. I just removed HeapTrace Unit from Linking and the problem has gone... No it has not gone. It is only hidden. That means you lowered the likelihood of it happening. The code still accesses an object that does not exist. That means random memory. Without heaptrc, you simple got better likelihood, that this random memory contains data, that does not cause a crash. But the bug is still there. It may still crash... Since it happens at form close, maybe you freed some component in your code? Changed owner of a component (moving to other form)? -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] SIGSEGV with Debug only
Martin, Even doesn't changing the Owner, the problem still.. O forgot to mention the content of ChangeOwner function procedure ChangeOwner(AComponente, NewOwner: TComponent); begin AComponente.Owner.RemoveComponent(AComponente); NewOwner.InsertComponent(AComponente); end; I suppose this function will handle all Notification changes, isn't ? []s Daniel Conheça o Projeto ACBr - Automaçao Comercial Brasil DJSystem a Loja Patrocinadora do ACBr De: Martin laza...@mfriebe.de Para: Daniel Simoes de Ameida dopidan...@yahoo.com.br; Lazarus mailing list lazarus@lists.lazarus.freepascal.org Enviadas: Sexta-feira, 30 de Março de 2012 13:49 Assunto: Re: [Lazarus] SIGSEGV with Debug only On 30/03/2012 17:14, Daniel Simoes de Ameida wrote: Martin, I use a Tab Style interface... (TDI)... so, I change the Owner/Parent in this function: APage := TFormPage.Create(nbForms) ; // This will call TFormPage.SetAForm procedure TFormPage.SetAForm(const AValue : TForm) ; begin fsAForm := AValue ; Caption := fsAForm.Caption; Color := fsAForm.Color; fsAForm.BorderStyle := bsNone ; fsAForm.Align := alClient ; // Change Aform Owner and Parent fsAForm.Parent := Self; ChangeOwner(fsAForm, Self); // AForm.FreeNotification(APage); I can't tell you 100% certain if this is related, but there is a chance it is to do with http://bugs.freepascal.org/view.php?id=21458 Setting the Owner of a component, does call Notify with opRemove and that breaks the FreeNotification system. Whenever the LCL sets a component to know about another it uses FreeNotification. So if one of the 2 is destroyed, the other one is informed and wiss not attempt to access the destroyed component. That also happens for anchors(since the 2 anchored components know about each other, they need to know, if one is destroyed) Due to the bug I mentioned, if you chang the owner, those notifications may no longer work. Depending on the order of calls and who knows whom, that can cause such a crash. Do you need to change the owner, or can you live with changing the parent only? The parent should be enough for displaying it. One of the things the owner will do, is clean up: if the owner is destroyed, so is the owned component. Maybe you can own things by the application? APage := TFormPage.Create(Application) ; -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] SIGSEGV with Debug only
On 30/03/2012 20:54, Daniel Simoes de Ameida wrote: Martin, Even doesn't changing the Owner, the problem still.. O forgot to mention the content of ChangeOwner function procedure ChangeOwner(AComponente, NewOwner: TComponent); begin AComponente.Owner.RemoveComponent(AComponente); NewOwner.InsertComponent(AComponente); end; I suppose this function will handle all Notification changes, isn't ? That is not that easy to answer. That depends on who owns what... Maybe even which classes are involved. To answer that I would have to read through some of the RTL/LCL rcode myself. It is not even sure that the bug is related to this. Though with the bug in place, I would avoid changing owners. It is possible with workarounds, but I can't foresee all the pitfalls. I had a quick look at the LCL code. Anchors to not seem to use FreeNotify When the app crashes, use the debugger, open the stack and make sure the frame selected is pointing to the source you posted (it may already be) Then evaluate self and/or self.fname to see which components refers to the missing anchor. That should help you find out which control the anchor pointed to. Maybe that holds some clue. Then you can debug again, and set breakpoints (in TControl.Destroy / wit condition on FName), and trying to find when the other control gets destroyed (if that is the problem, there are other possibilities...) Sorry this answer may appear a bit vague. But tracking that kind of issue can be very hard. -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
Re: [Lazarus] SIGSEGV with Debug only
On 3/30/2012 04:28, Martin Schreiber wrote: Am 30.03.2012 02:06, schrieb Daniel Simoes de Ameida: I'm using Debug Info as Auto (-g) and Display Line numbers (-gl), Heaptrace Unit is also active (-gh)in Debug mode ... Any hints ? Heaptrace fills freed memory with garbage. CurAnchorSide probably is in a object which already has been destroyed. ewww :( in my ancient mind, it would be better to fill with null for possible checks but then again ;) :P -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
[Lazarus] SIGSEGV with Debug only
Hi All I have a strange issue... I'm currently using Lazarus 0.9.31 (update from SVN) with FPC 2.6.0 When I compile my application with debug information, I always get a SIGSEGV when closing one of my forms,on line 4805 of control.inc This Image shows the error. However, when compiling without debug information, the errors do not occur (better this way) .. I'm using Debug Info as Auto (-g) and Display Line numbers (-gl), Heaptrace Unit is also active (-gh)in Debug mode ... Any hints ? []s Daniel Conheça o Projeto ACBr - Automaçao Comercial Brasil DJSystem a Loja Patrocinadora do ACBr -- ___ Lazarus mailing list Lazarus@lists.lazarus.freepascal.org http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
