[dmd-concurrency] priority messages

[Andrei Alexandrescu]

Michel Fortin wrote:
> Personally I'd tend to just not define any priority and deal with
> things in a FIFO manner to keep things simple. If you want to add
> complexity (priority), it should be justified by use cases. So which
> use case do you have in mind for priority?

Upon further thinking, I realized there's need for two orthogonal things:

1. Priority messages of any type. They'll be put to the front of the queue.

2. "Must handle" messages that unblock any call to receive(). They may 
or may not have priority. These may be derived from Exception.

It's never simple is it :o/.


Andrei