Mastering Functional Programming

Counting the responded actors

In the example, we counted the child actors that responded to an actor in order to determine when an actor is ready to respond to its parent actor:

answered += 1// ...if (answered == children.size) {  to ! Result(buffer)  context stop self}

This scenario can give rise to certain undesirable outcomes. First of all, it means the time that it takes for the system to respond is equal to the time it takes for the deepest and slowest link to be resolved and processed.

The logic behind this reasoning is as follows. The processing callback determines when a node of a processing tree is considered completed:

if (answered == children.size)

So a node is completed whenever its slowest child is completed. However, we should ...