Limit scope of all global std::once_flag #19111

once_flag is a helper (as the name might suggest) to execute a callable only once. Thus, the scope of the flag does never need to extend beyond where the callable is called. Typically this is function scope.

Move all the flags to function scope to

• simplify code review
• avoid mistakes where similarly named flags are accidentally exchanged
• avoid polluting the global scope

Concept ACK. Is g_ prefix in variable names still relevant now?

Is g_ prefix in variable names still relevant now?

Yes, they still have static storage duration, also the diff is smaller keeping it. Finally, to keep code consistent with other instances like g_logger.

ACK fa9c67559186f5416c1c0b26c0a1d5e72c234ccb, tested on Linux Mint 19.3 (x86_64).

Code review ACK fa9c67559186f5416c1c0b26c0a1d5e72c234ccb.