Dealing with an object corrupting the heap

Question

In my application I am creating an object pretty much like this :

connect() {
  mVHTGlove = new vhtGlove(params);
}

and once I am about to close application I call this one :

disconnect() {
  if (mVHTGlove) 
    delete mVHTGlove;
}

This call always triggers a breakpoint with the following message :

Windows has triggered a breakpoint in DesignerDynD.exe.

This may be due to a corruption of the heap, which indicates a bug in DesignerDynD.exe or any of the DLLs it has loaded.

This may also be due to the user pressing F12 while DesignerDynD.exe has focus.

The output window may have more diagnostic information.

I cannot modify the vhtGlove class to fix the corruption of the stack as it is an external library provided only in the form of header files, lib files and dlls.

Is there any way to use this class in a clean way ?

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**** EDIT ::: I tried to strip things down to a bare minimum, however I get the same results... here you have the ENTIRE code.

#include "vhandtk/vhtCyberGlove.h"
#include "vhandtk/vhtIOConn.h"
#include "vhandtk/vhtBaseException.h"

using namespace std;

int main(int argc, char* argv[])
{
   vhtCyberGlove* testGlove = NULL;

   vhtIOConn gloveAddress("cyberglove", "localhost", "12345", "com1", "115200");
   try
   {
      testGlove = new vhtCyberGlove(&gloveAddress,false);

      if (testGlove->connect())
         cout << "Glove connected successfully" << endl;
      else
      {
         throw vhtBaseException("testGlove()->connect() returned false.");
      }

      if (testGlove->disconnect())
      {
         cout << "Glove disconnected successfully" << endl;
      }
      else 
      {
         throw vhtBaseException("testGlove()->disconnect() returned false.");
      }

   }
   catch (vhtBaseException *e)
   {
      cout << "Error with gloves: " << e << endl;
      system("pause");
      exit(0);
   }

   delete testGlove;

   return 0;
}

Still crashes on deletion of the glove.

---

EDIT #2 :: If I just allocate and delete an instance of vhtCyberGlove it also crashes.

int main(int argc, char* argv[])
{
   vhtCyberGlove* testGlove = NULL;
   vhtIOConn gloveAddress("cyberglove", "localhost", "12345", "com1", "115200");
   testGlove = new vhtCyberGlove(&gloveAddress,false);
   delete testGlove; //<<crash!
   return 0;
}

Any ideas?

thanks!

JC

Answer 1

One possiblity is that mVHTGlove isn't being initialized to 0. If disconnect was then called without a connect ever being called, then you'd be attempting to deallocate a garbage pointer. Boom.

Another possibility is that you are actually corrupting the stack a bit before that point, but that is where the corruption actually causes the crash. A good way to check that would be to comment out as much code as you can and still get the program to run, then see if you still get the corruption. If you don't, slowly bring back in bits of code until you see it come back.

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Some further thoughts (after your edits).

You might check and see if the API doesn't have its own calls for memory management, rather than expecting you to "new" and "delete" objects manually. The reason I say this is that I've seen some DLLs have issues that looked a lot like this when some memory was managed inside the DLL and some outside.