How to return values via interface calls

• version

  1.1.1

• scope

  Example.

  This code is provided as example code for a user to base their code on.

• description

  How to return values via interface calls

• boards

  Unless otherwise specified, this example runs on the SliceKIT Core Board, but can easily be run on any XMOS device by using a different XN file.

Interface functions can return values. You declare them in the interface declaration as you would for a normal function:

interface my_interface {
  int get_value(void);
};

The client end of the interface can use the results of that interface function call:

void task1(client interface my_interface c) {
  int x;
  x = c.get_value();
  printintln(x);
}

When handling the function at the server end, you can declare a variable to hold the return value in the select case. This can be assigned in the body of the case and at the end of the case the value is returned back to the client.

void task2(server interface my_interface c) {
  int data = 33;
  select {
  case c.get_value() -> int return_val:
    // Set the return value
    return_val = data;
    break;
  }
}