Add locks on getLoggerInstance

If multiple threads try to get the logger instance, 2 logger instances might be created at the same time. This may or may not be an actual issue. Note that locks would impair the run time.

Example:

```C
// pseudo-code
getLoggerInstance() {
// get lock
if (!_logger)
_logger = new Logger();
// unlock
return _logger;
}
```

AC:

- add lock protection to getLoggerInstance

Locate getLoggerInstance in the driver and inspect how the logger singleton is initialized. Add the requested lock protection, then verify that concurrent calls cannot create multiple logger instances and consider the runtime cost noted in the issue.

Written by the indexing model from the issue text.