Content

Building from Source

A complete build of akka-serial involves two parts

  1. Building Scala sources (the front-end), resulting in a platform independent artifact (i.e. a jar file).

  2. Building C sources (the back-end), yielding a native library that may only be used on systems resembling the platform for which it was compiled.

Both steps are independent, their only interaction being a header file generated by the JDK utility javah (see sbt javah for details), and may therefore be built in any order.

Building Scala Sources

Run sbt core/package in the base directory. This simply compiles Scala sources as with any standard sbt project and packages the resulting class files into a jar.

Building Native Sources

The back-end is managed by CMake and all relevant files are contained in native/src.

Build Process

Several steps are involved in producing the native library:

  1. Bootstrap the build (run this once, if Makefile does not exist).

    1. Required dependencies: CMake (2.8 or higher), JDK (1.8 or above)
    2. Run cmake .
  2. Compile

    1. Run make. Note: should you encounter an error about a missing “jni.h” file, try setting the JAVA_HOME environment variable to point to the base path of your JDK installation.
  3. Install

    The native library is now ready and can be:

    • copied to a local directory: DESTDIR=$(pwd)/<directory> make install

    • installed system-wide: make install

    • put into a “fat” jar, useful for dependency management with sbt (see next section)

Creating a Fat Jar

The native library produced in the previous step may be bundled into a “fat” jar so that it can be included in sbt projects through its regular dependency mechanisms. In this process, sbt basically acts as a wrapper script around CMake, calling the native build process and packaging generated libraries. Running sbt native/package produces the fat jar in native/target.

Note: an important feature of fat jars is to include native libraries for several platforms. To copy binaries compiled on other platforms to the fat jar, place them in a subfolder of native/lib_native. The subfolder should have the name $(arch)-$(kernel), where arch and kernel are, respectively, the lower-case values returned by uname -m and uname -s.

Note About Versioning

The project and package versions follow a semantic pattern: M.m.p, where

Usually (following most Linux distribution’s conventions), shared libraries produced by a project name of version M.m.p are named libname.so.M.m.p. However, since when accessing shared libraries through the JVM, only the name can be specified and no particular version, the convention adopted by akka-serial is to append M to the library name and always keep the major version at zero. E.g. libakkaserial.so.3.1.2 becomes libakakserial3.so.0.1.2.

Testing

The samples directory contains fully functional application examples of akka-serial. To run an example, change to the base directory of akka-serial and run sbt samples/run. All projects, including samples, can be listed by running `sbt projects`.

To be able connect you can use real device (arduino) burned with sample-echo (dev/arduino-terminal) code, or create Virtual Serial Port pair

socat (SOcket CAT) – multipurpose relay – is a command line based utility that establishes two bidirectional byte streams and transfers data between them. socat is #4 on the Top 100 Network Security Tools list, available in most distro repositories (on Debian/Ubuntu sudo apt-get install socat does the trick), really light on resources, and very efficient.

To create a pair of VSP’s socat -d -d pty,raw,echo=0 pty,raw,echo=0

you will get something like

socat[5894] N PTY is /dev/ttys002
socat[5894] N PTY is /dev/ttys003
socat[5894] N starting data transfer loop with FDs [5,5] and [7,7]

and that’s it! As long as the socat is running, you have a pair of VSP’s open (their names are printed by socat on initialization). See socat man page for more details on what the above command does. Now You can connect to first socket ( in this case /dev/ttys002) using some sample (or Your code), and use second for monitoring or/and sending messages To send - use command

echo 'Hello World' > /dev/ttys003

To listen - use command

cat < /dev/ttys003

Connecting executable and VSP

socat -d -d pty,raw,echo=0 "exec:myprog ...,pty,raw,echo=0"

where the executable myprog will be connected with the VSP through stdio.

For example Echo-server would look like

socat -d -d pty,raw,echo=0 "exec:/bin/cat,pty,raw,echo=0"

Publishing and Releasing

Releases are handled automatically by the continuous integration and deployment system, Travis CI. A release will be performed for every annotated Git tag that is pushed to the main repository.

Here are a couple of observations on the release process: