Heap Corruption in richedit - Managed C++/CLI Discussion Boards

Re: TreelistView c++/cli

jschell22-Aug-23 6:41

jschell

22-Aug-23 6:41

Temblor wrote:
cli project...TreelistView

So 'cli' is command line interface.

So a CUI for a tree list view?

My take is you have three options.
1. Get different requirements so it is not needed at all.
2. The tree is going to be very shallow. And probably very short. So roll your own.
3. This isn't going to work.

Why the third? For example sometimes I recurse a directory tree via the command line looking for files or even all files. I can certainly view that in a console but it is basically worthless because there is so much data. Even if I am just looking for one specific file I still need a search mechanism. So I route to a file and then use an editor to search.

But lets say you are not looking for a actual file system. So what is the growth rate of this tree? If it is shallow and small in 10 years rolling your own still works. And the users can use it. But if your growth rate is not small then in 10 years the users will have something they can't use.

If I was asked to do this and I already knew that the tree was not small then I would push back on the requirements. In writing (like email.) And if they insisted I would first make a copy of that email and my response. Then I would just roll my own (still not that hard.) It would be their problem when it was unusable. But I might use a demo with data from 10 years from now - just so they can see what is going to happen.

Re: TreelistView c++/cli

Peter_in_278022-Aug-23 17:20

Peter_in_2780

22-Aug-23 17:20

jschell wrote:
So 'cli' is command line interface.

No. See .NET programming with C++/CLI | Microsoft Learn[^] for example. It's some bastardisation of "Interface to CLR (Common Language Runtime)".

Software rusts. Simon Stephenson, ca 1994. So does this signature. me, 2012

Re: TreelistView c++/cli

Temblor22-Aug-23 20:54

Temblor

22-Aug-23 20:54

let explain some inf

I succeed in displaying sql data in a treeView all i need now is another column so i can display another data like (balance) in it

something like objectListView

it's not for showing system files

btw I saw some devs made what you taking about (file system in treeView) in C++ / MFC

Re: TreelistView c++/cli

Richard MacCutchan22-Aug-23 21:48

Richard MacCutchan

22-Aug-23 21:48

jschell wrote:
cli project...
So 'cli' is command line interface.

The forum, title, and indeed the question specifically stated c++/cli, which is the C++ version of code that compiles into .NET IL.

modified 23-Aug-23 4:23am.

Re: TreelistView c++/cli

jschell23-Aug-23 6:47

jschell

23-Aug-23 6:47

Re: TreelistView c++/cli

Gerry Schmitz23-Aug-23 5:49

Gerry Schmitz

23-Aug-23 5:49

"Columns" are an illusion. If you only have "one column / item / field" (that you can identify), concatenate multiple fields together (as strings) with padding and / or a "separator" (e.g. "|")

"Before entering on an understanding, I have meditated for a long time, and have foreseen what might happen. It is not genius which reveals to me suddenly, secretly, what I have to say or to do in a circumstance unexpected by other people; it is reflection, it is meditation." - Napoleon I

Re: TreelistView c++/cli

Temblor23-Sep-23 3:54

Temblor

23-Sep-23 3:54

FINALLY
I MADE IT Wink | ;)

Heap Corruption in richedit

ForNow15-Jan-23 12:49

ForNow

15-Jan-23 12:49

Hi

I am getting a heap corruption. I am running under the visual studio debugger. and the exception is at

Quote:

ntdll.dll!RtlReportCriticalFailure() Unknown

My scenario is I have a DLL reading and formatting data for a .exe. I keep a record count so when I get a exception, at

Quote:
ntdll.dll!RtlReportCriticalFailure() Unknown

I insert code if (recordcount == 0x0000196e) __debugbreak; I then start stepping through the code looking for the problem how ever when stepping through the code works I try this multiple times however when I stop the code where the exception were to occur it always complete successfully

The listing I am trying to to inset in the richedit is huge about 153 pages 30 lines to page, 134 bytes across I roughly calculate the number of bytes I am trying to insert into the richedit is 1.6 meg. I am not sure if the size is the issue I do a Rciheditctrl::LimitText with the amount bytes I need

Again when break on the offending record and step thru the code it completes normally

Here is the stack frame My code starts a the DriveRichedit.exe

ntdll.dll!RtlReportCriticalFailure() Unknown
ntdll.dll!RtlpHeapHandleError() Unknown
ntdll.dll!RtlpHpHeapHandleError() Unknown
ntdll.dll!RtlpLogHeapFailure() Unknown
ntdll.dll!RtlpHeapFindListLookupEntry() Unknown
ntdll.dll!RtlpFindEntry() Unknown
ntdll.dll!RtlpAllocateHeap() Unknown
ntdll.dll!RtlpAllocateHeapInternal() Unknown
riched20.dll!CTxtArray::AddBlock(long,long) Unknown
riched20.dll!CTxtArray::SplitBlock(long,long,long,long,int) Unknown
riched20.dll!CTxtPtr::InsertRange(long,unsigned short const *) Unknown
riched20.dll!CRchTxtPtr::ReplaceRange(long,long,unsigned short const *,class IUndoBuilder *,long,long *,unsigned long) Unknown
riched20.dll!CTxtRange::ReplaceRange(long,unsigned short const *,class IUndoBuilder *,enum SELRR,long *,unsigned long) Unknown
riched20.dll!CTxtRange::CheckLimitReplaceRange(long,unsigned short const *,int,class IUndoBuilder *,unsigned long,long *,long,int,unsigned long) Unknown
riched20.dll!CTxtRange::CleanseAndReplaceRange(long,unsigned short const *,int,class IUndoBuilder *,unsigned short *,long *,unsigned long) Unknown
riched20.dll!CLightDTEngine::ReadPlainText(class CTxtRange *,struct _editstream *,int,class IUndoBuilder *,long) Unknown
riched20.dll!CLightDTEngine::LoadFromEs(class CTxtRange *,long,struct _editstream *,int,class IUndoBuilder *) Unknown
riched20.dll!CTxtEdit::TxSendMessage(unsigned int,unsigned __int64,__int64,__int64 *) Unknown
riched20.dll!RichEditWndProc() Unknown
riched20.dll!RichEditANSIWndProc() Unknown
user32.dll!UserCallWinProcCheckWow() Unknown
user32.dll!CallWindowProcAorW(__int64 ,struct HWND__ *,enum _WM_VALUE,unsigned __int64,__int64,int) Unknown
user32.dll!CallWindowProcA() Unknown
mfc140d.dll!CWnd::DefWindowProcA(unsigned int nMsg, unsigned __int64 wParam, __int64 lParam) Line 1100 C++
mfc140d.dll!CWnd::WindowProc(unsigned int message, unsigned __int64 wParam, __int64 lParam) Line 2100 C++
mfc140d.dll!AfxCallWndProc(CWnd * pWnd, HWND__ * hWnd, unsigned int nMsg, unsigned __int64 wParam, __int64 lParam) Line 265 C++
mfc140d.dll!AfxWndProc(HWND__ * hWnd, unsigned int nMsg, unsigned __int64 wParam, __int64 lParam) Line 418 C++
mfc140d.dll!AfxWndProcBase(HWND__ * hWnd, unsigned int nMsg, unsigned __int64 wParam, __int64 lParam) Line 299 C++
user32.dll!UserCallWinProcCheckWow() Unknown
user32.dll!SendMessageWorker() Unknown
user32.dll!SendMessageInternal(struct HWND__ *,unsigned int,unsigned __int64,__int64,int) Unknown
user32.dll!SendMessageA() Unknown
mfc140d.dll!CRichEditCtrl::StreamIn(int nFormat, _editstream & es) Line 775 C++
> DriveRichEdit.exe!CProgDebug::OnInitDialog() Line 136 C++
[External Code]
DriveRichEdit.exe!CMainFrame::PROGDEBUG() Line 48 C++
[External Code]
DriveRichEdit.exe!WinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, char * lpCmdLine, int nCmdShow) Line 26 C++
[External Code]

Re: Heap Corruption in richedit

Victor Nijegorodov15-Jan-23 20:26

Victor Nijegorodov

15-Jan-23 20:26

I am curios, are you using the MFC code in a Managed C++/CLI application? Confused | :confused:

Re: Heap Corruption in richedit

ForNow16-Jan-23 0:10

ForNow

16-Jan-23 0:10

I’m not apparently I posted in the wrong forum I meant to post in the MFC forum

trying to understand DLL and Thread local storage

ForNow4-Dec-22 8:52

ForNow

4-Dec-22 8:52

Hi

I have been looking at the examples off dll and TLS

First thing I noticed that

C++

DWORD g_dwThreadIndex;

is in global storage

It would be nice as in the IBM manuals would have registers on at entry to DllMain

I mean is the SP (register) that of the calling application

regardless if the index returned from tlsalloc lets say is 5

and then before the current thread access the storage set by tlssetvalue

another thread does a tlsallloc g_dwThreadindex becomes 6

then the first thread then does tlsgetvalue it would be using 6 instead of 5 obviously I am not understanding something

I mean if gw_dwThreadindex would be defined in the callers stack I would get it

more so is the anyway of knowing the identity of the caller I mean maybe process id or thread guess I could do a call to Startupinfo

Re: trying to understand DLL and Thread local storage

Richard Deeming4-Dec-22 21:42

Richard Deeming

4-Dec-22 21:42

We don't know which examples you've been looking at. But the whole point of thread-local storage is that it's local to the thread; one thread cannot modify a TLS variable for another thread. (At least not without jumping through several flaming hoops whilst drenched in LPG and holding a large firework.)

Each thread gets its own copy of the TLS variable. If thread A set it to 5, and thread B sets it to 6, thread A will still see it set to 5.

Thread Local Storage | Microsoft Learn[^]

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Re: trying to understand DLL and Thread local storage

ForNow5-Dec-22 2:40

ForNow

5-Dec-22 2:40

I am refering to the following example i found in the codeproject my lack of understanding is due to the fact that gw_dwThreadIndexis defined in global storage not stack/local storage

C++

Shrink ▲   
struct ThreadData {
    // some thread specific data
};
...
DWORD g_dwThreadIndex;

extern "C" BOOL WINAPI DllMain(HINSTANCE hInstance, 
                      DWORD dwReason, LPVOID /*pReserved*/)
{
    ThreadData* pData;

    switch (dwReason) {
        case DLL_PROCESS_ATTACH:

            // allocate a TLS index

            g_dwThreadIndex = ::TlsAlloc();
            if (g_dwThreadIndex == TLS_OUT_OF_INDEXES)
                return FALSE;

            //break;        // execute the DLL_THREAD_ATTACH code

        case DLL_THREAD_ATTACH:

            // allocate memory for this thread

            pData = (ThreadData*) ::LocalAlloc(LPTR, sizeof(ThreadData));
            if (pData == 0)
                return FALSE;

            ::TlsSetValue(g_dwThreadIndex, (LPVOID) pData);
            break;

        case DLL_THREAD_DETACH:

            // release memory for this thread

            pData = (ThreadData*) ::TlsGetValue(g_dwThreadIndex);
            if (pData != 0)
                ::LocalFree((HLOCAL) pData);
            break;

        case DLL_PROCESS_DETACH:

            // release memory for this thread

            pData = (ThreadData*) ::TlsGetValue(g_dwThreadIndex);
            if (pData != 0)
                ::LocalFree((HLOCAL) pData);

            // release the TLS index

            ::TlsFree(g_dwThreadIndex);
            break;
    }

    return TRUE;
}

    ...
};

Re: trying to understand DLL and Thread local storage

Richard Deeming5-Dec-22 4:29

Richard Deeming

5-Dec-22 4:29

I'm not a C++ person, but as far as I can see, the only place you write to the g_dwThreadIndex variable is in the DLL_PROCESS_ATTACH code. According to Microsoft, that means:

DllMain entry point (Process.h) - Win32 apps | Microsoft Learn[^]
The DLL is being loaded into the virtual address space of the current process as a result of the process starting up or as a result of a call to LoadLibrary. DLLs can use this opportunity to initialize any instance data or to use the TlsAlloc function to allocate a thread local storage (TLS) index.

As far as I can see, that will only ever happen once per process. And the documentation explicitly says that this is the correct time to call TlsAlloc.

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Re: trying to understand DLL and Thread local storage

ForNow5-Dec-22 4:41

ForNow

5-Dec-22 4:41

Just realized posted to wrong forum however the variable is in static or global storage the next thread that comes by can change its value thats my problem just about all the. examples for TLS and DLL s have it this way

Re: trying to understand DLL and Thread local storage

Richard Deeming5-Dec-22 6:01

Richard Deeming

5-Dec-22 6:01

ForNow wrote:
the next thread that comes by can change its value

Well yes, if you do it wrong you can shoot yourself in the foot.

As far as I can see, the example you're looking at is not doing it wrong. The global variable is initialized once, in the place where the documentation says it should be initialized.

This seems to be a case of "if I stick a fork in my toaster whilst it's switched on, I can get an electric shock; therefore, all toasters are dangerous and should be banned". Smile | :)

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Re: trying to understand DLL and Thread local storage

ForNow5-Dec-22 7:39

ForNow

5-Dec-22 7:39

This example works if the DLL is servicing only one address space but if it’s system DLL than I think there would be a problem ?

Re: trying to understand DLL and Thread local storage

Richard MacCutchan5-Dec-22 5:56

Richard MacCutchan

5-Dec-22 5:56

I'm not sure I quite understand what you are asking, but each thread gets its own stack (pointed at by SP) which provides all the thread local storage. It can also allocate its own storage through the normal methods. You have not really explained what g_dwThreadIndex is being used for in relation to the question. Does this all relate to some article, or specific MSDN page?

Re: trying to understand DLL and Thread local storage

ForNow5-Dec-22 7:33

ForNow

5-Dec-22 7:33

Richard I think I’m begging to understand the source of my confusion
First it is my understanding there are Two types off DLL one for the entire operating system in my case windows 10 and one servicing threads of one address space if it’s the former I mean that works like USER.DLL then the code example of tls wouldn’t work an I right in this ?

Re: trying to understand DLL and Thread local storage

Richard MacCutchan5-Dec-22 7:54

Richard MacCutchan

5-Dec-22 7:54

No there is only one type of DLL, which is a Dynamically Loadable Library. However, it may, or may not, be thread safe, depending on how it is created. Most (all?) of the Windows provided DLLs are thread safe. And the whole point of having DLLs is that the system only needs to load it once, to service multiple executables (i.e. address spaces). Be that as it may, I am still not sure what your concern is with regard to threads.

Re: trying to understand DLL and Thread local storage

ForNow5-Dec-22 8:00

ForNow

5-Dec-22 8:00

I’m sure you are right ( or else nothing would work )

I think what I have to do is have 2 exe both load the same DLL run under it under visual studio debugger and look at the address thanks

Re: trying to understand DLL and Thread local storage

jschell5-Dec-22 6:06

jschell

5-Dec-22 6:06

The actual source of the code referenced

Using Thread Local Storage in a Dynamic-Link Library - Win32 apps | Microsoft Learn[^]

Following is also relevant to see the messages.

DllMain entry point (Process.h) - Win32 apps | Microsoft Learn[^]

The code example is skipping the normal TLS semantics. So in other words it is using the first TLS index for all storage. Within the code provided.

This might follow into the following comment...

ForNow wrote:
and then before the current thread access the storage set by tlssetvalue
another thread does a tlsallloc g_dwThreadindex becomes 6

Not exactly sure what you are saying there but I think you are presuming that somehow this initialization code is not thread safe. In that it might be called by multiple threads at the same time. This code method will never be called by more than one thread at a time. Additionally the 'DLL_PROCESS_ATTACH' will never be called more than once (within one process space of course.)

Re: trying to understand DLL and Thread local storage

ForNow5-Dec-22 7:37

ForNow

5-Dec-22 7:37

Hi

I think I’m begging to understand the source of my confusion
It is my understanding there are two types of dll’s
One services the entire os like kerenel.DLL and one just a particular address space if my code is of the former than this example is not PROCESS safe am I correct in my understanding ?

Re: trying to understand DLL and Thread local storage

jschell12-Dec-22 10:21

jschell

12-Dec-22 10:21

ForNow wrote:
there are two types of dll’s

Sort of true but also not true.

When a dll is loaded the whatever loaded it decides how to use it. In one case the defining characteristic of an 'application' is that it must have a defined entry point and other defined behaviors. That is true for every operating system (not just windows and dlls.)

The code above provides a defined entry point.

Other dlls might just be libraries and they might have many 'entry' points (methods) although how each of those is defined (laid out in the dll) defines whether it can be successfully called and even how it must be called.

All of that is rather esoteric though and is almost never going to be an issue.

Good news, /clr builds will soon add C++ 20 support!

John Schroedl15-Nov-22 5:49

John Schroedl

15-Nov-22 5:49

Here's some good news for anyone dealing with C++/CLI:

Stephan Lavavej recently committed changes to the VC STL which will remove a number of the roadblocks and warnings we've hit using C++/CLI in recent years. The rest of our codebase is moving to use C++20 constructs and the /clr code has had problems.

The PR: Enable /clr C++ 20 support #3194

John

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