EUC 2006: Erlang Message Receive Fundamentals: Scatter / Gather (2 of 4)

Scatter / Gather (2 of 4)

Change the gather function to not care about message order

     gather(Pids) when is_list(Pids) ->
       gather(length(Pids), []).

     gather(0, Results) ->
       Results;
     gather(Count, Results) ->
       receive
         {Pid, Item, Result} -> gather(Count-1, [{Item, Result} | Results])
       end.

     exec_fun(Parent, Fun, Item) ->
       Parent ! {self(), Item, catch(Fun(Item))}.

Now we handle the results in the order they are returned
The results are not in input order, so we tag them and return a proplist
Notice that gather is now tail recursive
But what if a processor doesn't respond?