Erlang Ring Benchmark

ringbench.erl

-module(ringbench).

-export([go/2]).

go(M, N) when is_integer(M), M > 1, is_integer(N), N > 1 ->
  io:format("~p processes, ~p messages~n", [N, M]),
  T = erlang:monotonic_time(),
  {FirstPid, FirstRef} = spawn_monitor(fun() -> first() end),
  LastPid = lists:foldl(fun(_, Pid) -> spawn_link(fun() -> loop(Pid) end) end, FirstPid, lists:seq(2, N)),
  io:format("processes spawned in ~p usec~n", [dt(T)]),
  FirstPid ! {go, LastPid, M, erlang:monotonic_time()},
  receive {'DOWN', FirstRef, _, _, _} -> ok end.

first() ->
    receive {go, LastPid, I, T} -> LastPid ! {I, T}, loop(LastPid) end.

loop(NextPid) ->
  receive
    die ->
          NextPid ! die;
    {1, T} ->
          io:format("messages sent in ~p us~n", [dt(T)]),
          NextPid ! die;
    {I, T} ->
          NextPid ! {I - 1, T},
          loop(NextPid)
  end.

dt(T) ->
    Dt = erlang:monotonic_time() - T,
    erlang:convert_time_unit(Dt, native, microsecond).