This library is intended to be a useful set of extensions to the WPI-provided library, providing reliable concurrency and diagnostics. However, parts of it have to be explained. The socket library is pretty simple; it's basically an abstraction over berkeley sockets. However, the concurrency and sockets code needs some explanation.

Concurrency

Most of the concurrency code is an abstraction over pthreads, which in this case is also an abstraction over the vxworks threads. We may or may not change this to vxworks threads (notable advantages of this are threads showing up as named in the diagnostics section of wind river). The main advantage we have over just starting pthreads is that if an object inherits from thread::start, similar to the 'Runnable' interface in java, the entry point of the thread will call the member function 'run(void*)' of that object, allowing the use of member variables and methods.

Diagnostics

Diagnostics were tricky; we aimed to have a simple interface that allows you to register an input or an output and have it show up on a web interface. To do this, we implemented an interface (pure virtual class), which we then created (or will create, at the time of writing) concrete subclasses for each of the sensors/effectors in wpilib. We had to do this since none of the sensors really shared a useful interface to get or set them. However, it does mean that you can call diagnostics_center#register_device() with any wpilib sensor, without the need to wrap it in an intermediary (or rather, it gets wrapped in an intermediary implicitly). Since this can be fairly confusing, an example follows:

Build Environment

cb8a82 in the closed loop branch enables the following macros: NR_CLOSED_LOOP_CONTROL - Switches drive code to closed loop control when set.