The Old New Thing

Non-psychic debugging: If somebody's complaining that a collection should be empty but isn't, you might want to see what's in there

January 31, 2014 Jan 31, 2014 01/31/14

Raymond Chen

A programmer on the GHI team (yes, the same GHI team) reported that they were hitting an assertion failure using an internal library and asked for help debugging it. // All factories should be unregistered by now assert(m_pFactoryList->IsEmpty()); "Can somebody help me figure out which factory it is that did not get unregistered?" I...

Can process IDs be greater than 64000? Because we're seeing process IDs greater than 64000

January 30, 2014 Jan 30, 2014 01/30/14

Raymond Chen

A customer asked what to me was a very strange question. Can process IDs be greater than 64000? Because we're seeing process IDs greater than 64000. This is a strange question because the answer is right there: You're seeing process IDs greater than 64000 with your very own eyes. Do you doubt the evidence right there in front of you? It...

One of my favorite error codes: Optional parameter missing

January 29, 2014 Jan 29, 2014 01/29/14

Raymond Chen

The error Optional parameter missing sounds awfully paradoxical, doesn't it. I mean, if the parameter is optional, why are you complaining that it's missing? This KB article explains why, specifically, the part that says, "If a parameter is omitted, the calling program must…". For those who don't want to click through, here's the ...

How can I make a callback function a member of my C++ class?

January 27, 2014 Jan 27, 2014 01/27/14

Raymond Chen

Instead of a Little Program today, I'm going to answer a Little Question. This is a common beginner question, but I figure I'll just spell it out right here for posterity. First of all, you probably noticed that you can't do this: class CountWindows { public: int CountThem(); private: BOOL CALLBACK WndEnumProc(HWND hwnd, LPARAM lParam...

Non-psychic debugging: Looking for leaked objects by their vtable

January 24, 2014 Jan 24, 2014 01/24/14

Raymond Chen

A programmer on the GHI team reported that they were hitting an assertion failure using an internal library and asked for help debugging it. ABC!CFactoryBase::AssertZeroRef+0x2e ABC!CFactoryBase::Unregister+0x1c ABC!CWidgetFactory::Unregister+0x2d DEF!CWidgetManager::Uninitialize+0x4a DEF!CWidget::`scalar deleting destructor'+0xd ABC!...