Frequently Asked Questions

This Section is a compilation of the most common questions via GitHub, chat, and mailing list.

Can I Encrypt CAF Communication?

Yes, by using the OpenSSL module (see Free Functions).

Can I Create Messages Dynamically?

Yes.

Usually, messages are created implicitly when sending messages but can also be created explicitly using make_message. In both cases, types and number of elements are known at compile time. To allow for fully dynamic message generation, CAF also offers message_builder:

message_builder mb;
// prefix message with some atom
mb.append(strings_atom::value);
// fill message with some strings
std::vector<std::string> strings{/*...*/};
for (auto& str : strings)
  mb.append(str);
// create the message
message msg = mb.to_message();

What Debugging Tools Exist?

The scripts/ and tools/ directories contain some useful tools to aid in development and debugging.

scripts/atom.py converts integer atom values back into strings.

scripts/demystify.py replaces cryptic typed_mpi<...> templates with replies_to<...>::with<...> and atom_constant<...> with a human-readable representation of the actual atom.

scripts/caf-prof is an R script that generates plots from CAF profiler output.

caf-vec is a (highly) experimental tool that annotates CAF logs with vector timestamps. It gives you happens-before relations and a nice visualization via ShiViz. There is an associated RFC for more information on caf-vec.