Error 1608 (from Emergency Stop)

[BillMe]

Dug into the Actor.vi inner workings and as you suggested, regardless of my helper loops,  I can remove the Handle Error override from all but the top level actor. There's 40 VIs I don't need.

Thanks.

[justACS]

BillMe wrote:

Dug into the Actor.vi inner workings and as you suggested, regardless of my helper loops,  I can remove the Handle Error override from all but the top level actor. There's 40 VIs I don't need.

Thanks.

My work here is done. 

[BillMe]

I use Emergency Stop to short circuit message processing ( a couple of actors can potentially have a backlog that might take a second or two to process). I disregard the 1608 in the app controller Handle Error override.

[AristosQueue (NI)]

It can be part of normal operation if you do something like:

Spawn 2 actors each searching a different database (or chunk of database) for some entry. Each of those two spawns two more, splitting their chunk in half. Those divide, repeat until you get down to a reasonable chunk size. Eventually, one of those actors finds what you're looking for and sends a result up the tree. As each higher-level actor gets the result, it sends E-Stop to its other branch to make that branch (and its nested actors) quit instantly.

There are lots of other "short circuit this operation" situations. Sending E-Stop is no different than throwing an exception in C++/JAVA/C#... sometimes it is done as an error, and sometimes it is done as a fast way to unroll a deep stack.

[AristosQueue (NI)]

The design you're asking for was in the original AF implementation that I had in 2009. Lots of feedback from users over two iterations convinced me that it was an excessive burden on the vast majority of message implementations to have the extra output. Using the error output addressed those issues. The stop signals propagating as errors helps with lots of other minor situations, but that's the main reason. So even if I redesigned AF from scratch, I'd stick with the error output.