Instruction update for the Heap tracker and question about azure-sphere-gallery HOT 2 CLOSED

Hi @bawilless, thank you for the feedback!

RE: warnings logs, your assumption is correct: by design, the GNU function wrapping applies to the user code and linked static libraries, it cannot apply within libraries that are embedded in the OS image or not linked to your App's executable.

Because from within the free() function itself the caller cannot be determined, unfortunately the wrapped-free-function can't intercept i.e. OS calls and ignore them. That is the reason for that log and the existence of the special _free() function.

Although, if the caller of the native free() is actually freeing memory that was not allocated by your App, that warning can be ignored and just seen as a heads-up; instead, in case your App did own that pointer being logged, then that would be something you want to make sure to account, as that amount of memory being freed will not be tracked in the global heap_allocated variable.

My suggestion is that once you have insured that your App is fully using the _free() wrapper, you could eventually just comment out that log. One useful thing that log does tell though, is exactly what lead you to your assumption (i.e. the calls from outside your code), which in a debugging phase may be useful information (i.e. wither a pointer is being freed for you already by external libraries).

We'll consider this valuable feedback in improving the library. Stay tuned! ;)

from azure-sphere-gallery.

Closing this as feedback is taken.

One more thing, starting from OS 21.07, heap memory tracking now detail separately the heap used by shared libraries:

https://docs.microsoft.com/azure-sphere/app-development/application-memory-usage#add-heap-memory-allocation-tracking

from azure-sphere-gallery.