printf not thread safe but OS uses it

I found out from tech help that printf is not thread safe and that a mutex should be used.

OK, that’s a pain but I can set up a mutex for that.

But what can be done about libraries that use it? For example, plugging in an ethernet cable results in a printf.

Is there any way to check to see if a printf is in progress?

I have found the answer…
Keep posting here such a helpful posts…