Algorithm is capable of using framework-supported logging

[knoepfel]

DUNE US S&C R&D item 078

[knoepfel]

One concern is how to support logging from algorithms written in separate languages. For example, a logging library for C++ might be spdlog, but a logging library for Python might be the logging module. Messages logged using these libraries should be coordinated.

One approach of doing this is https://github.com/tanghaibao/pybind11_log.

[marcpaterno]

One of the major things to determine in this milestone is how it is that an algorithm is to get access to the log to which it writes. There seem to be two major options:

1. The algorithm receive an argument that provides the access.
2. The logging facility provide functions that write to some global facility.

In either case, the framework must ensure thread safety of the algorithms that use the logging facility. What are the thread efficiency ramifications of each of these choices?