CString Format causes memory issue
in [MFC]
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From: Jen on 23 Aug 2006 09:28 Ajay, The string looks exactly like I need it after this function call. I am in release mode, so I put AfxMessageBox(queryStr.GetBuffer(0)), and the string is fine. I then use this string to call Access to perform a query and that is also exactly what I want. The program just gives me an error when i close it. If I comment out these lines, and instead hard cord in the query, I don't get the error after closing. Thanks! Jen Ajay Kalra wrote: > queryStr.Format("Avg(IIf(E1.Param%d=0,0,(T1.Param%d-E1.Param%d)/(E1.Param%d)*100))",paramNum+1,paramNum+1,paramNum+1,paramNum+1); > > Can you step in this method and see if this is working correctly. Is > the string as you expect after this function call? > > --- > Ajay
From: Ajay Kalra on 23 Aug 2006 09:34 > The string looks exactly like I need it after this function call. I am > in release mode, so I put AfxMessageBox(queryStr.GetBuffer(0)), and the > string is fine. I then use this string to call Access to perform a > query and that is also exactly what I want. That would mean CString did whatever it was supposed to do. I had assumed from your post that problem is in CString and I dont think thats the case. > The program just gives me an error when i close it. If I comment out > these lines, and instead hard cord in the query, I don't get the error > after closing. That does not mean that the problem lies in that line of code. Its very very likely to be elsewhere. Keep in mind that CString has been in use for a long time and you can safely assume that its doing its job. --- Ajay
From: Jen on 27 Aug 2006 19:20 Well I tried replacing all .Format commands with Ed's suggestion of using a buffer, and still got the error. So I believe that I have a random memory problem that only shows up in Release mode. Any tips on how to track it down? I just don't know what to try! Jen
From: Ed Weir (ComCast) on 27 Aug 2006 19:39 "Jen" <leonard522(a)aol.com> wrote in message news:1156720829.837574.267440(a)i3g2000cwc.googlegroups.com... | | Well I tried replacing all .Format commands with Ed's suggestion of | using a buffer, and still got the error. | | So I believe that I have a random memory problem that only shows up in | Release mode. Any tips on how to track it down? I just don't know | what to try! | | Jen IIRC, when you removed the format for the query and replaced it with a string const, the problem went away? Did you try removing the query itself to test? I'm thinking that perhaps the response could be overstepping allocated memory or stack frame. As Joe has mentioned before in previous posts, this kind of bug is nightmarish to resolve. Years ago I used SoftICE to solve hard to track problems like this, but even that is not easy... Wish I could help more! -- Ed. ----------------------------------------------------- In dictatorships, you need courage to fight evil; in the free world, you need courage to see the evil." ?Natan Sharansky F9E7707A2AF502D0A899C6ACB43A2D35EB7E->bin->b64
From: Jen on 27 Aug 2006 20:19
Hi ~ I replaced the .Format and used constants and left the query in. Then I ran the program and it worked fine. I haven't tried removing the query itself, but it works with a constant, so I thought that couldn't be the problem? I did try to use Application Verifier 3.2 to track the problem down, and the program crashes leaving the following log: <?xml version="1.0" encoding="UTF-8" standalone="no" ?> - <avrf:logfile xmlns:avrf="Application Verifier"> - <avrf:logSession TimeStarted="2006-08-27 : 20:09:17" PID="3944" Version="1"> - <avrf:logEntry Time="2006-08-27 : 20:09:23" LayerName="Heaps" StopCode="0x8" Severity="Error"> <avrf:message>Corrupted heap block.</avrf:message> <avrf:parameter1>2a21000 - Heap handle used in the call.</avrf:parameter1> <avrf:parameter2>45ceac - Heap block involved in the operation.</avrf:parameter2> <avrf:parameter3>0 - Size of the heap block.</avrf:parameter3> <avrf:parameter4>d6413f2e - Reserved</avrf:parameter4> - <avrf:stackTrace> <avrf:trace>vrfcore!VfCoreRedirectedStopMessage+81</avrf:trace> <avrf:trace>ntdll!RtlpNtMakeTemporaryKey+393d</avrf:trace> <avrf:trace>ntdll!RtlpNtMakeTemporaryKey+4a4b</avrf:trace> <avrf:trace>ntdll!RtlpNtMakeTemporaryKey+4c4e</avrf:trace> <avrf:trace>ntdll!RtlpNtMakeTemporaryKey+7cef</avrf:trace> <avrf:trace>ntdll!RtlInitializeSListHead+115c0</avrf:trace> <avrf:trace>ntdll!iswdigit+128</avrf:trace> <avrf:trace>vfbasics!AVrfpRtlFreeHeap+16b</avrf:trace> <avrf:trace>msvcrt!free+c3</avrf:trace> <avrf:trace>vfbasics!AVrfp_free+1f</avrf:trace> <avrf:trace>MFC42!Ordinal6667+43</avrf:trace> <avrf:trace>EtrackerTrends!+402841</avrf:trace> </avrf:stackTrace> </avrf:logEntry> + <avrf:logEntry Time="2006-08-27 : 20:09:26" LayerName="TLS" StopCode="0x352" Severity="Error"> <avrf:message>Using an invalid TLS index.</avrf:message> <avrf:parameter1>7abba - TLS index</avrf:parameter1> <avrf:parameter2>0 - Not Used.</avrf:parameter2> <avrf:parameter3>0 - Not Used.</avrf:parameter3> <avrf:parameter4>0 - Not Used.</avrf:parameter4> - <avrf:stackTrace> <avrf:trace>vfbasics!CheckTlsIndex+ce</avrf:trace> <avrf:trace>vfbasics!AVrfpTlsSetValue+3b</avrf:trace> <avrf:trace>MFC42!Ordinal2427+90</avrf:trace> <avrf:trace>MFC42!Ordinal806+28</avrf:trace> <avrf:trace>vrfcore!VfCoreStandardDllEntryPointRoutine+127</avrf:trace> <avrf:trace>vfbasics!AVrfpStandardDllEntryPointRoutine+10e</avrf:trace> <avrf:trace>ntdll!LdrInitializeThunk+29</avrf:trace> <avrf:trace>ntdll!LdrShutdownProcess+142</avrf:trace> <avrf:trace>kernel32!IsValidLocale+8eb</avrf:trace> <avrf:trace>kernel32!ExitProcess+14</avrf:trace> <avrf:trace>vfbasics!AVrfpExitProcess+3a</avrf:trace> <avrf:trace>EtrackerTrends!CCycleData::operator=+da76</avrf:trace> <avrf:trace>kernel32!RegisterWaitForInputIdle+49</avrf:trace> </avrf:stackTrace> </avrf:logEntry> </avrf:logSession> </avrf:logfile> Any ideas on how to track it down from here? Thanks ~ Jen |