It is global data, because it can (and should be) used without threading it through 155 functions.
In terms of the relational data model, it is global data because there is always one, and only one, of it.
In terms of the relational data model, it is global data because there is always one, and only one, of it.
If your logging routine touches your windowing handle that certainly makes it more complex. If I'm meant to know that your logging routine doesn't touch your windowing handle, that's precisely the statement that it isn't global data.