The latest in coin-flipping technology, this program will flip any desired amount of coins at once, using a random generator of your most refined choice.

The purpose of the project is to benchmark and verify uniformness of random number generators, while providing an easy-to-use server-client model, allowing you to flip coins using thousands of CPU-saturated nodes at once. Fun for whole family!

It does so by counting occurences of coin flip streaks of any length (between 1 and 128). The client nodes generate coin flips and send their statistics to the server.

See it in action here!

With Docker:

docker build -t coinflipper .

Building without Docker requires an implementation of Google's Protocol Buffers compiler (protobuf), ZeroMQ, CLI11, GNU Make, a C++11-able C++ compiler (e.g. GCC >=4.7.0, Clang), and a sensible build environment.

Run make. It's that easy! (Protocol buffers are generated automatically during build)

Coin Flipper utilises a server-client model, so both your server and your client(s) must have it compiled, and have network connectivity between each other.

What you should first set up is the server. Run ./coinflipper server on the desired server machine. The server will attempt to load the state from state.cf file, if it exists. It will also periodically save the state to the same file as well as timestamped dumps in the history/ directory.

The next thing you want to do is run ./coinflipper flipper <server address> on each of the client nodes you wish to configure (the more the merrier!). You can optionally specify the number of worker threads with -j <threads> (defaults to number of CPU cores).

You can spectate the accumulated statistics on the server by running ./coinflipper status <server address> from any machine that has network connectivity to the server.

That's it! You're done! Enjoy your coin flips!

Run server:

docker run -p 5555:5555 -p 5556:5556 tibordp/coinflipper:latest

Run the flipper:

docker run tibordp/coinflipper:latest flipper <server>

Check the status:

docker run tibordp/coinflipper:latest status <server>

Coinflipper is also Kubernetized, like any modern app ought be! You can deploy Coinflipper server and 2 workers on a cluster of your choice by

kubectl apply -f kubernetes/coinflipper.yaml

The server component will run as a StatefulSet with 1GiB of persistent storage mounted, so you will never lose your progress even if you restart the pod.

There is also a web frontend available, so you can watch the flipping progress without a terminal. See here for deployment instructions.

The project uses clang-format for code formatting. To install pre-commit hooks:

pip install pre-commit
pre-commit install

This will automatically format code on commit. You can also run formatting manually:

clang-format -i src/*.cc src/*.h

Licensed under MIT (http://opensource.org/licenses/MIT), but do try to use it only for Good™.