// Commentary:
//
// Here is an example of a model that deadlocks.  The interface has a
// bye event in the !idle state to avoid the interface from deadlocking
// due to the world event not occurring since it is optional.  Because
// the optional world is not guaranteed to occur and component does not
// accept or use the bye event on either port this model has a potential
// deadlock.
//
// Code:

interface ihelloworld
{
  in void hello();
  in void bye();
  out void world();

  behavior
  {
    bool idle = true;
    [idle] on hello: idle = false;
    [!idle] {
      on bye: idle = true;
      on optional: {idle = true; world;}
    }
  }
}

component deadlock
{
  provides ihelloworld h;
  requires ihelloworld w;

  behavior
  {
    on h.hello(): w.hello();
    on w.world(): {}
  }
}