interface with events and commands - cannot signal event

Question

I found it difficult to signal an event in nesC. Can anyone help? (EDIT: I omitted MainC components in code below).

I have defined a simple interface:

interface MyInterface {
    command uint8_t action();
    event void actionDone();
}

It has one action and one event.

What's more I have one component which provides MyInterface:

configuration MyComponentC {
    provides interface MyInterface[uint8_t id];
}
implementation {
    components MyComponentM;
    MyInterface = MyComponentM.MyInterface;
}


module MyComponentM {
    provides interface MyInterface[uint8_t id];
}
implementation {
    command uint8_t MyInterface.action[uint8_t id]() {...}
    ...
    event void bar() {
        signal MyInterface.actionDone[foo]();
    }
}

Event bar is from completely different interface. In this event I want to signal event actionDone with id == foo.

I have also "main" component:

configuration MyAppC {
}
implementation {
    components MyC as App;
    components MyComponentC as MC;
    App.MyInterface -> MC.MyInterface[unique("Hello")];
}

module MyC {
    uses interface MyInterface;
}
implementation {
    event void MyInterface.actionDone() {...}
}

But during compilation I get an error:

MyInterface.actionDone not connected

Where did I make a mistake? How to properly connect components?

Answer 1

Not sure if this is the cause, but in your App try referring to MyC via alias, i.e. instead of

MyC.MyInterface -> MS.MyInterface[unique("Hello")];

try

App.MyInterface -> MS.MyInterface[unique("Hello")];

[UPDATE]

As explained in this link, since you are using parametrized interface and that there is no guarantee that all 256 instances will be wired to something you need to provide a default implementation in MyComponentM module

default event MyInterface.actionDone[foo]() {
    return;
}