This is the C implementation of APX.

Operating System	APX Server	APX Client
Windows (native)	(testing)	(in development)
Windows (cygwin)	(testing)	(testing)
Linux (native)	(testing)	(testing)
APX for embedded systems	(not in scope)	(testing)

An APX server is a message broker that clients connects to using sockets. It's basically an APX router wrapped in a layer that provides socket communication. You can either use the default APX server (with sockets) or you can add your own communication adapters like for instance IPC.

The APX router is the main (internal) component of an APX server. When started, it waits for connections from clients. On connection, each client uploads an .apx file to the router then waits for port data.

An .apx file is an ASCII text file written in APX Text containing information about what port signatures it provides and what port signatures it requires.

The APX router uses this information to dynamically create data routes between provide and require ports of all connected APX nodes (the clients). When a node/client writes/updates port data on one of its provide ports the router automatically routes that data to all (connected) require ports of other APX nodes.

An APX client implements one or more APX nodes. It connects to an APX server in order to send/receive port data.

All dependencies needed to build APX for C are available in this git repository and its submodules. It is known to work for both Windows and Linux (it's all a single code base).

• For Linux: Build with gcc, both makefile(s) and eclipse projects are available in this git repository.
• For Windows: Build for cygwin using gcc or build for Windows using Visual Studio (2010 and 2015 has been verified to work so far).

I'm using my own sockets library called msocket. It's a thin helper library for dealing with the sockets API in a portable manner (it uses BSD sockets API on Linux and Winsock2 API on Windows).

For APX I'm using my own implemenations of commonly used data structures .

• adt_ary: similar to QList
• adt_bytearray: similar to QByteArray
• adt_hash: similar to QHash
• adt_list: similar to QLinkedList
• adt_str: similar to QString

A version of APX where all use of dynamic memory and underlying OS calls has been removed is currently being worked on. The intent with this version is to enable APX clients to run on embedded devices such as IoT devices or automotive ECUs. More information about this version will be provided once implementation progresses.