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Random access violations
Posted: Tue 10 Aug 2010 08:55
by zd
Hello!
There is a strange error that keeps appearing totally randomly, only on Vista/Windows 7 systems (at least I've not seen it XP yet!) and I think it might be related to IBDAC.
I'm getting two kinds of error messages:
1. Access violation at address 057E36EF in module 'fbclient.dll'. Write of address 4F4C09FD.
2. Access violation at address 77996BF0 in module 'ntdll.dll'. Write of address 00000050.
Luckily, I'm using EurekaLog to trace back errors, and I have found the following:
1. The error usually happens when TIBCQuery.Open OR TIBCQuery.ExecSQL is called.
2. The error occurs at totally random times and can't be reproduced intentionally. Sometime it doesn't occur for weeks and sometimes it just strikes out of nowhere.
3. As I mentioned already, the error occurs only on Windows Vista/7, never on XP.
Now here is some more info, that Eurekalog shows:
Call stack for the fbclient.dll error:
Address Module Procedure/Method
057EB30B fbclient.dll gds__free
057EB300 fbclient.dll gds__free
057F2E90 fbclient.dll gds__thread_exit
Assembler for the fbclient.dll error:
Code: Select all
057E36D7 mov eax, [ecx+$08]
057E36DA test eax, eax
057E36DC push esi
057E36DD lea esi, [ecx+$0C]
057E36E0 push edi
057E36E1 mov edi, [esi]
057E36E3 jz +$13
057E36E5 test edi, edi
057E36E7 mov [eax], edi
057E36E9 jz +$00000089
057E36EF mov [edi-$04], eax ; <-- EXCEPTION
057E36F2 pop edi
057E36F3 pop esi
057E36F4 pop ebp
057E36F5 ret $04
Address Module Procedure/Method
77712E7B ntdll.dll RtlEnterCriticalSection
1000BA5D fbclient.dll gds__alloc
1000BA50 fbclient.dll gds__alloc
100132F0 fbclient.dll gds__thread_enter
1001FF60 fbclient.dll isc_dsql_allocate_statement
Assembler for the ntdll error:
Code: Select all
; RtlEnterCriticalSection (Line=0 - Offset=0)
; -------------------------------------------
77712E69 mov edi, edi
77712E6B push ebp
77712E6C mov ebp, esp
77712E6E sub esp, +$0C
77712E71 push esi
77712E72 push edi
77712E73 mov edi, [ebp+$08]
77712E76 lea esi, [edi+$04]
77712E79 mov eax, esi
77712E7B lock ; <-- EXCEPTION
77712E7C DB $0F, $BA, $30, $00 // dword ptr [eax], $00
77712E80 jnb +$00022E6E
77712E86 mov eax, dword ptr [$0018]
77712E8C mov ecx, [eax+$24]
77712E8F mov [edi+$0C], ecx
77712E92 mov dword ptr [edi+$08], $00000001 ; ''...
More background info:
This happens under Firebird 2.1.1.
I've tried connecting to the server using fbclient.dll of Firebird 2.1.3, but the same keeps happening.
I'm using Delphi7 with an older version of IBDAC (2.50.0.39).
Any ideas?
Thanks!
Posted: Thu 12 Aug 2010 07:31
by Dimon
Please, check that you don't free objects (e.g. TIBCConnection) a few times, for example, in the main and secondary threads. IBDAC can work in multithread applications, so it is thread safe. But the restriction is that you cannot use one component for more than one thread simultaneously.
Also please, try to download the latest IBDAC build (3.10.0.15) and check if this problem still exists.
Posted: Fri 13 Aug 2010 12:58
by zd
Hello!
I'm using only one connection object and it's only freed upon program termination, automatically.
Please note that apart from the main thread, no other thread is using any of the IBDAC components.
There is an OLE automation server in the program but it uses the "tmSingle" threading model - thus its DB calls should be executed in the program's main thread. And you also have to know that when these errors occured in the past, nothing was using the automation server.
The problem with upgrading to a newer version of IBDAC is that it could likely introduce new bugs (in the past upon upgrading to newer versions certain issues came up from time to time) and I can't go through the whole application right now to test it for possible problems caused by the upgrade.
The other problem is that sometimes the problem doesn't occur for weeks on the test computers, but I do get Eurekalog error reports with this issue from users of the program.
BTW: The program relies heavily TIBCAlerter, is there a chance the it could be causing these problems?
Any other ideas?
Thanks!
Posted: Fri 13 Aug 2010 14:00
by Dimon
I can not reproduce the problem.
Please, try to download the latest IBDAC build (3.10.0.15) and check if this problem still exists.
Posted: Sat 14 Aug 2010 18:43
by zd
Is there anything that makes you believe that this bug has been corrected in the newest release? Because I'd really hate to invest expensive days of testing due to the upgrade just to have the same issue come up...
Thanks!
Posted: Sat 14 Aug 2010 18:49
by zd
BTW: Here is a memory dump for the ntdll.dll issue. Who knows, it might be able to help!
Code: Select all
Registers:
-----------------------------
EAX: 00000050 EDI: 0000004C
EBX: 00000000 ESI: 00000050
ECX: 0000004C ESP: 0012F38C
EDX: 00001638 EIP: 77996BF0
Stack: Memory Dump:
------------------ ---------------------------------------------------------------------------
0012F38C: FFFFFFFF 77996BF0: F0 0F BA 30 00 0F 83 B0 F3 00 00 64 A1 18 00 00 ...0.......d....
0012F390: 01F70014 77996C00: 00 8B 48 24 89 4F 0C C7 47 08 01 00 00 00 5F 33 ..H$.O..G....._3
0012F394: 02201CE0 77996C10: C0 5E 8B E5 5D C2 04 00 68 5D D7 96 77 64 FF 35 .^..]...h]..wd.5
0012F398: 00000000 77996C20: 00 00 00 00 8B 44 24 10 89 6C 24 10 8D 6C 24 10 .....D$..l$..l$.
0012F39C: 0012F468 77996C30: 2B E0 53 56 57 A1 E8 71 A2 77 31 45 FC 33 C5 50 +.SVW..q.w1E.3.P
0012F3A0: 00000024 77996C40: 89 65 E8 FF 75 F8 8B 45 FC C7 45 FC FE FF FF FF .e..u..E..E.....
0012F3A4: 10003DC0 77996C50: 89 45 F8 8D 45 F0 64 A3 00 00 00 00 C3 8B 4D F0 .E..E.d.......M.
0012F3A8: 0000004C 77996C60: 64 89 0D 00 00 00 00 59 5F 5F 5E 5B 8B E5 5D 51 d......Y__^[..]Q
0012F3AC: FFFFFFFF 77996C70: C3 CC 41 00 70 00 69 00 50 00 6F 00 72 00 74 00 ..A.p.i.P.o.r.t.
0012F3B0: 00000000 77996C80: 00 00 53 00 68 00 61 00 72 00 65 00 64 00 53 00 ..S.h.a.r.e.d.S.
0012F3B4: 0012F408 77996C90: 65 00 63 00 74 00 69 00 6F 00 6E 00 00 00 43 00 e.c.t.i.o.n...C.
0012F3B8: 00000000 77996CA0: 53 00 52 00 50 00 4F 00 52 00 54 00 21 00 00 00 S.R.P.O.R.T.!...
0012F3BC: 00000000 77996CB0: 43 00 41 00 50 00 54 00 55 00 52 00 45 00 00 00 C.A.P.T.U.R.E...
0012F3C0: 000000F5 77996CC0: 00 00 5C 00 53 00 65 00 73 00 73 00 69 00 6F 00 ..\.S.e.s.s.i.o.
0012F3C4: 1000BA62 77996CD0: 6E 00 73 00 5C 00 25 00 6C 00 64 00 5C 00 57 00 n.s.\.%.l.d.\.W.
0012F3C8: 00000024 77996CE0: 69 00 6E 00 64 00 6F 00 77 00 73 00 5C 00 53 00 i.n.d.o.w.s.\.
Posted: Mon 16 Aug 2010 09:39
by Dimon
Unfortunately, the information you have provided is not enough to reproduce your issue.
Posted: Fri 15 Oct 2010 15:09
by zd
Hello Dimon!
I've upgraded to the latest version of IBDAC and unfortunately, the same problem has just reappeared.
It appears totally hectically (sometimes the problem doesn't appear for days), but always when my program is trying to execute a query using IBDAC. (The exact query doesn't matter, it usually happens at different parts of the program)
Please note that this time it's you who'll need to look into the IBDAC code as there is no way I can consistently reproduct this.
Here are two error logs, the first appeared after executing a query, the second one in the same session after executing another one!
Code: Select all
2.2 Address : 100036EF
2.3 Module Name : fbclient.dll - (Firebird SQL Server)
2.4 Module Version: 2.1.3.18185
2.5 Type : EAccessViolation
2.6 Message : Access violation at address 100036EF in module 'fbclient.dll'. Write of address 4F4C09FD.
--------------------------------------------------------------------------------------------------------------------
|Address |Module |Unit |Class |Procedure/Method |Line |
--------------------------------------------------------------------------------------------------------------------
|Running Thread: ID=4536; Priority=0; Class=; [Main] |
|------------------------------------------------------------------------------------------------------------------|
|1000B30B|fbclient.dll| | |gds__free | |
|1000B300|fbclient.dll| | |gds__free | |
|77A87C91|ntdll.dll | | |RtlMultiByteToUnicodeN | |
|77A848CE|ntdll.dll | | |NtFindAtom | |
|76FAA299|user32.dll | | |EndPaint | |
|76FB1020|user32.dll | | |PtInRect | |
|76FB0B31|user32.dll | | |SendMessageW | |
|76FBB754|user32.dll | | |CallWindowProcA | |
|76FBB73E|user32.dll | | |CallWindowProcA | |
|77A68AB0|ntdll.dll | | |RtlLeaveCriticalSection | |
|76F9A986|user32.dll | | |GetCapture | |
|76FA8B77|user32.dll | | |DispatchMessageA | |
|76FA8B6D|user32.dll | | |DispatchMessageA | |
|77BED0E7|kernel32.dll| | |BaseThreadInitThunk | |
|------------------------------------------------------------------------------------------------------------------|
2.2 Address : 77A68B02
2.3 Module Name : ntdll.dll - (NT réteg DLL)
2.4 Module Version: 6.0.6002.18005
2.5 Type : EAccessViolation
2.6 Message : Access violation at address 77A68B02 in module 'ntdll.dll'. Write of address 00000050.
2.7 ID : 4C99
----------------------------------------------------------------------------------------------------------------
|Address |Module |Unit |Class |Procedure/Method |Line |
----------------------------------------------------------------------------------------------------------------
|*Exception Thread: ID=4536; Priority=0; Class=; [Main] |
|--------------------------------------------------------------------------------------------------------------|
|77A68B02|ntdll.dll | | |RtlEnterCriticalSection | |
|76FA6B3C|user32.dll | | |CharUpperBuffA | |
|1000BA5D|fbclient.dll| | |gds__alloc | |
|1000BA50|fbclient.dll| | |gds__alloc | |
|100132F0|fbclient.dll| | |gds__thread_enter | |
|1001FF60|fbclient.dll| | |isc_dsql_allocate_statement| |
|77A87C91|ntdll.dll | | |RtlMultiByteToUnicodeN | |
|77A848CE|ntdll.dll | | |NtFindAtom | |
|76FB1020|user32.dll | | |PtInRect | |
|76FB0B31|user32.dll | | |SendMessageW | |
|76FBB754|user32.dll | | |CallWindowProcA | |
|76FBB73E|user32.dll | | |CallWindowProcA | |
|77A8427E|ntdll.dll | | |NtAlpcSendWaitReceivePort | |
|77A68AB0|ntdll.dll | | |RtlLeaveCriticalSection | |
|76F9A986|user32.dll | | |GetCapture | |
|76FA8B77|user32.dll | | |DispatchMessageA | |
|76FA8B6D|user32.dll | | |DispatchMessageA | |
|77BED0E7|kernel32.dll| | |BaseThreadInitThunk | |
|--------------------------------------------------------------------------------------------------------------|
Thank you!
Posted: Thu 21 Oct 2010 17:00
by zd
Hello! Any news about this?
I'm in desperate need of solving this problem as today it arise again.
I believe this must be an error in the IBCAlerter component!
Attaching newer details:
Code: Select all
2.3 Module Name : fbclient.dll - (Firebird SQL Server)
2.4 Module Version: 2.1.3.18185
2.5 Type : EAccessViolation
2.6 Message : Access violation at address 04BC36EF in module 'fbclient.dll'. Write of address 4F4C09FD.
2.7 ID : 096B
|04BCB30B|fbclient.dll| | |gds__free | |
|04BCB300|fbclient.dll| | |gds__free | |
|007A8EDE|MyProg.exe|mainmenu.pas |TMain |DBAlerterEvent |5899[45] |
|76B28B77|user32.dll | | |DispatchMessageA | |
|76B28B6D|user32.dll | | |DispatchMessageA | |
|0085AE82|MyProg.exe|MyProg.dpr | | |369[215] |
|7648D0E7|kernel32.dll| | |BaseThreadInitThunk | |
|--------------------------------------------------------------------------------------------------------------|
2.3 Module Name : ntdll.dll - (NT réteg DLL)
2.4 Module Version: 6.0.6002.18005
2.5 Type : EAccessViolation
2.6 Message : Access violation at address 77A68B02 in module 'ntdll.dll'. Write of address 00000050.
2.7 ID : E2EC
|77A68B02|ntdll.dll | | |RtlEnterCriticalSection | |
|04BCBA5D|fbclient.dll| | |gds__alloc | |
|04BCBA50|fbclient.dll| | |gds__alloc | |
|04BD32F0|fbclient.dll| | |gds__thread_enter | |
|76489C43|kernel32.dll| | |CompareStringW | |
|76489BEB|kernel32.dll| | |CompareStringW | |
|04BDFF60|fbclient.dll| | |isc_dsql_allocate_statement| |
...
Please let me know if I have started investing this issue!
Thanks
Posted: Thu 28 Oct 2010 12:43
by Dimon
Please specify the IBDAC version you are using.
Posted: Fri 29 Oct 2010 07:20
by zd
Hello Dimon!
I'm using 3.50.0.17.
Any ideas?
Posted: Tue 02 Nov 2010 11:08
by Dimon
We have fixed this problem. This fix will be included in the next IBDAC build.
Posted: Wed 10 Nov 2010 22:43
by zd
Thanks, I'm currently testing the new version and I'll report back if the problem is gone!