RE: debug assertion error in threads of c++ under windows

=?Utf-8?B?V2lt?= <>
Mon, 12 Mar 2007 05:43:26 -0700
"Pushpa" wrote:

Hi All,

This my part of the c++ program using threads in windows :

//modified by pushpa
struct structExrdDoc
    CExrdDoc* spDoc;
    LPCTSTR sstrFileName;

structExrdDoc sp;

volatile bool running;

UINT CExcelExport::run(LPVOID p)
    CExrdDoc* me = sp.spDoc;
    me->OnSaveDocument ((LPCTSTR)sp.sstrFileName);
    running = FALSE;
    return 0;
//modified by pushpa

void CExcelExport::SaveExcelFile (CExrdDoc* pDoc, const string&
    sp.spDoc = pDoc; //modified by pushpa
    sp.sstrFileName = strFileName.c_str(); //modified by pushpa
    running = TRUE; //modified by pushpa
    AfxBeginThread(run,NULL); //modified by pushpa
    //pDoc->OnSaveDocument (strFileName.c_str()); //modified by pushpa

Here the line of code I have commented was taking lot of time, so I hv
tried to use threads and I am new to this.

This is the declaration in the .h file

    static UINT CExcelExport::run(LPVOID p);

After some struggle I could compile the application, but when it is
run I am getting a Debug assertion error.

debug assertion failed!
for information on how your program can cause an assertion failure,
see the visual c++ documentation on asserts.

Could you please help me with this.

Thanking you in advance,

Probably the string where the strFileName reference parameter was referring
to went out of scope while (or before) your thread was running.

If that happened, sstrFileName in this line points to invalid memory:
me->OnSaveDocument ((LPCTSTR)sp.sstrFileName);

Making sstrFileName a string or CString in stead of LPCTSTR will fix this.

Also you're mixing string with LPCTSTR which won't work if you compile for


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