Starting point: provide an ExecutionContext

Your back-end entry point is the implementation of the ExecutionContext interface

• Many complicated functions
• Fortunately, you can just extend from AbstractExecutionContext
  • Just a single instance() method left virtual, basically a call to the constructor.
  • You can see how’s implemented in the simulator for a clue

Expose device capabilities

The ExecutionContext also holds device capabilities (it’s like the System / Runtime singletons of Java).

• A number of interfaces for standard capabilities are provided
  • TimeAwareDevice — Implement this if your device is able to estimate network message delays and lags
  • SpatiallyEmbeddedDevice — Implement this if your device is able to estimate distances to its neighbors (with whatever metric)
  • LocalizedDevice — If your device has access to its position (e.g., if a GPS system is onboard)
• You are free to add any method, and access it via calls to self
• The thing usually implemented is something along the line of MyExecutionContext extends AbstractExecutionContext implements TimeAwareDevice, LocalizedDevice

Implement communication

Communication is dealt with by the NetworkManager

• void shareState(Map<CodePath,Object> toSend)
  • You are in charge of finding a way to send your neighbors the toSend payload…
• Map<DeviceUID,Map<CodePath,Object>> getNeighborState()
  • …and of presenting the payloads sent from others to the current device.

Run

Now that pieces are in place, just create a ProtelisVM and run whatever you like, e.g.:

final NetworkManager netmgr = new MyNetworkManager(...);
final ExecutionContext ctx = new MyExecutionContext(netmgr, ...);
final ProtelisProgram prog = ProtelisLoader.parse(myProgram)
final ProtelisVM vm = new ProtelisVM(prog, ctx);
while (alive) {
  vm.runCycle();
  Thread.sleep(someTime);
}