In my application I'm getting this error:
HEAP[App.exe]: HEAP: Free Heap block 61af0f0 modified at 61af194 after it was freed
Here is a call stack:
ntdll.dll!_RtlpBreakPointHeap@4() Unknown
ntdll.dll!@RtlpAllocateHeap@24() Unknown
ntdll.dll!_RtlAllocateHeap@12() Unknown
ntdll.dll!_RtlDebugAllocateHeap@12() Unknown
ntdll.dll!@RtlpAllocateHeap@24() Unknown
ntdll.dll!_RtlAllocateHeap@12() Unknown
> msvcr110d.dll!_heap_alloc_base(unsigned int size) Line 57 C
msvcr110d.dll!_heap_alloc_dbg_impl(unsigned int nSize, int nBlockUse, const char * szFileName, int nLine, int * errno_tmp) Line 431 C++
msvcr110d.dll!_nh_malloc_dbg_impl(unsigned int nSize, int nhFlag, int nBlockUse, const char * szFileName, int nLine, int * errno_tmp) Line 239 C++
msvcr110d.dll!_nh_malloc_dbg(unsigned int nSize, int nhFlag, int nBlockUse, const char * szFileName, int nLine) Line 302 C++
msvcr110d.dll!malloc(unsigned int nSize) Line 56 C++
msvcr110d.dll!operator new(unsigned int size) Line 59 C++
App.exe!std::_Allocate<char>(unsigned int _Count, char * __formal) Line 28 C++
App.exe!std::allocator<char>::allocate(unsigned int _Count) Line 591 C++
App.exe!std::basic_stringbuf<char,std::char_traits<char>,std::allocator<char> >::overflow(int _Meta) Line 152 C++
msvcp110d.dll!std::basic_streambuf<char,std::char_traits<char> >::sputc(char _Ch) Line 196 C++
msvcp110d.dll!std::ostreambuf_iterator<char,std::char_traits<char> >::operator=(char _Right) Line 634 C++
msvcp110d.dll!std::num_put<char,std::ostreambuf_iterator<char,std::char_traits<char> > >::_Put(std::ostreambuf_iterator<char,std::char_traits<char> > _Dest, const char * _Ptr, unsigned int _Count) Line 1553 C++
msvcp110d.dll!std::num_put<char,std::ostreambuf_iterator<char,std::char_traits<char> > >::_Iput(std::ostreambuf_iterator<char,std::char_traits<char> > _Dest, std::ios_base & _Iosbase, char _Fill, char * _Buf, unsigned int _Count) Line 1544 C++
msvcp110d.dll!std::num_put<char,std::ostreambuf_iterator<char,std::char_traits<char> > >::do_put(std::ostreambuf_iterator<char,std::char_traits<char> > _Dest, std::ios_base & _Iosbase, char _Fill, long _Val) Line 1216 C++
msvcp110d.dll!std::num_put<char,std::ostreambuf_iterator<char,std::char_traits<char> > >::put(std::ostreambuf_iterator<char,std::char_traits<char> > _Dest, std::ios_base & _Iosbase, char _Fill, long _Val) Line 1137 C++
msvcp110d.dll!std::basic_ostream<char,std::char_traits<char> >::operator<<(int _Val) Line 311 C++
App.exe!TUtil::intToString(int val) Line 43 C++
App.exe!TFontManager::getFont(const std::basic_string<char,std::char_traits<char>,std::allocator<char> > & filename, int size) Line 15 C++
App.exe!TButton::draw() Line 55 C++
App.exe!TWindow::draw() Line 203 C++
App.exe!TGUIManager::drawObjects() Line 49 C++
App.exe!TGameAppLayer::gameCycle() Line 456 C++
App.exe!TGameAppLayer::mainLoop() Line 520 C++
App.exe!wWinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, wchar_t * lpCmdLine, int nCmdShow) Line 36 C++
App.exe!__tmainCRTStartup() Line 528 C
App.exe!wWinMainCRTStartup() Line 377 C
kernel32.dll!@BaseThreadInitThunk@12() Unknown
ntdll.dll!___RtlUserThreadStart@8() Unknown
ntdll.dll!__RtlUserThreadStart@8() Unknown
So from what I know, the error I'm getting is caused by accessing (deleting again) block of memory which was already freed. It's already a third day of trying finding out what exactly is wrong with my code. During this time, I found some small memory leaks which I already fixed, and now Visual Leak Detector tells me it doesn't detect any leak.
Yet the problem with heap corruption remains.
In each place of my code in a place where "delete" operator is being used, I check first if a pointer isn't nullptr. If not, I set it to nullptr:
if(m_pVar != nullptr)
{
delete m_pVar;
m_pVar = nullptr;
}
So it seems like there shouldn't be a problem with freeing same block of memory more than once.
I was trying to figure something out from this call stack, but that's place in which I'd like to ask you for a help. In a call stack it seems like a problem is with string allocation, but what exactly may this mean? The last MY function that is being called is string TUtil::intToString(int val) Line 43, so it may be easier if I show you a body of that function:
std::string TUtil::intToString(int val)
{
std::ostringstream s;
s << val; // Here's line 43
return s.str();
}
Sometimes call stack is different, so string TUtil::intToString(int val) function doesn't even exist in it, but it ALWAYS has something to do with strings allocations.
I hope it's clear what I just said. If you need more information, please tell me and I'll provide it in edit to this question.
m_pVar? – Sheathing