Pool allows for parallel processing of items. When creating a pool a Worker
and Reducer are provided. The worker accepts input and produces one output
value for every input value. The reducer reduces the output from the worker
into a single resulting value. Once created you can add input values to the
pool using add(). Once all input has been added you can invoke either
wait() or wait_handle() to wait for all input to be processed and
retrieve the reduced output value.
Reducer is responsible for reducing multiple inputs into a single output.
This is used by the workpool to condense multiple work outputs to a single
output.