I am creating a hardware source block and ran into an issue where the destructor for the block does not appear to get called when closing the flowgraph. This is problematic because I'm using the destructor to release hardware resources. I finally discovered that the problem only exists when using the "function probe" block to poll the block. Simply disabling the function probe block in the flowgraph allows the destructor to run correctly.
I verified this behavior by creating a simple block with a single printf() statement in the constructor and destructor, as well as one in a probe function. The destructor printf() does not get called when polling the probe function.
Any idea why this happens or how to fix it?
Thanks!