K-Meter | System meter according to Bob Katz | Plugin library

I'm working on an application which polls for the states and peak levels of audio sessions on the default audio rendering endpoint every X milliseconds, and implements some logic based on that. It seems to run fine on Windows 10, but on Windows 7 I get occasional crashes when I change the default playback device (e.g. when I switch between my USB headset and the PC speaker). The exact line where the crash occurs changes between runs, but it's usually when I access the IAudioSessionControl or IAudioSessionControl2 pointers to make various WASAPI calls. What I could glean from the stack traces created by ProcDump and analyzed by WinDbg is that the COM objects representing audio sessions are destroyed when the default playback device has changed (even though I had obtained and am still holding pointers to those objects' interfaces), and then my polling thread crashes randomly in places where I access them through the interface pointers. I figured that maybe I'm doing something wrong, so this led me to Matthew van Eerde's blog and sample, where he does the same querying (and more), but for all available audio endpoints in the system. So I modified his sample program to do it every 5 milliseconds and only for the default rendering endpoint, and I get the same occasional crashes on Windows 7.

Here is a stripped-down version of the sample, which sometimes results in crashes when switching between playback devices. I usually get the crash within ~2 minutes of switching back-and-forth between devices. YMMV.