How to use interfaces to connect to multiple tasks

• version

  1.0.0

• scope

  Example.

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

• description

  How to use interfaces to connect to multiple tasks

• 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.

The following example shows three tasks running in parallel and communicating. The task3 function receives messages from either task1 or task2.

void task1(interface my_interface client c) {
  c.msgA(5, 10);
}

void task2(interface my_interface client c) {
  c.msgA(20, 25);
}

void task3(interface my_interface server c,
           interface my_interface server d) {
  for (int i=0; i < 2; i++) {
    // wait for either msgA or msgB over connection c.
    select {
    case c.msgA(int x, int y):
      printf("Received msgA from interface end c: %d, %d\n", x, y);
      break;
    case d.msgA(int x, int y):
      printf("Received msgA from interface end d: %d, %d\n", x, y);
      break;
    }
  }
}

int main(void) {
  interface my_interface c;
  interface my_interface d;
  par {
    task1(c);
    task2(d);
    task3(c, d);
  }
  return 0;
}

You can also connect to multiple tasks over the same interfaces using interface arrays.