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Development

Development is currently coordinated by Steffen Vogel post@steffenvogel.de at VILLASframework GitHub organization. Please feel free to submit pull requests or bug reports.

Please follow our contribution guide when creating pull requests at GitHub.

Programming Paradigm​

VILLASnode is currently written in C/C++ using the ISO C11 and C++17 standards while following an object oriented programming paradigm.

Main classes in VILLASnode are:

In order to track the life cycle of those objects, each of them has an enum State member. The following figure illustrates the normal transition through the states of a Node type:

stateDiagram-v2 [*] --> initialized: _init() / Node#58;#58;Node() initialized --> parsed: _parse() / Node#58;#58;parse() parsed --> checked: _check() / Node#58;#58;check() checked --> prepared: _prepare() / Node#58;#58;prepare() prepared --> started: _start() / Node#58;#58;start() started --> stopped: _stop() / Node#58;#58;stop() stopped --> started: _start() / Node#58;#58;start() stopped --> destroyed: _destroy() / Node#58;#58;~Node() destroyed --> [*]

Be aware that, when a fatal error occures _destroy / Node::~Node() will be called, no matter the previous state of the node. Also note that _read() / Node::read() and _write() / Node::write() are guaranteed to only be called in the started state. Please rely on the guaranteed state transition order and do not replicate these state transitions within your node type's implementation.

Shared library: libvillas.so​

VILLASnode is split into a shared library called libvillas and a couple of executables (villas-node, villas-pipe, villas-test, villas-signal, ...) which are linked against this library.

Plugins​

There are many places where VILLASnode can easily extended with additional functionality via plugins: