simple_one_for_one child can not start

Question

I write some code to test simple_one_for_one supervisor, but it can not work, the code is:

-module(test_simple_one_for_one).

-behaviour(supervisor).

%% API
-export([start_link/0, start_fun_test/0]).

%% Supervisor callbacks
-export([init/1]).

-define(SERVER, ?MODULE).

%%--------------------------------------------------------------------
start_link() ->
    {ok, Pid} = supervisor:start_link({local, ?SERVER}, ?MODULE, []).

start_fun_test() ->
    supervisor:start_child(test_simple_one_for_one, []).

init([]) ->
    RestartStrategy = simple_one_for_one,
    MaxRestarts = 1000,
    MaxSecondsBetweenRestarts = 3600,

    SupFlags = {RestartStrategy, MaxRestarts, MaxSecondsBetweenRestarts},

    Restart = permanent,
    Shutdown = 2000,
    Type = worker,

    AChild = {fun_test_sup, {fun_test, run, []},
          Restart, Shutdown, Type, [fun_test]},
    io:format("start supervisor------ ~n"),
    {ok, {SupFlags, [AChild]}}.

When I run

test_simple_one_for_one:start_link().

and

test_simple_one_for_one:start_fun_test().

in erl shell, it gives me error:

test_simple_one_for_one:start_fun_test(). ** exception exit: {noproc,{gen_server,call, [test_simple_one_for_one,{start_child,[]},infinity]}} in function gen_server:call/3 (gen_server.erl, line 188)

Answer 1

If it's all the code you've written for the test, beware that when you register a supervisor child you suplly a {M, F, A} tuple which represent the function called when you start a child.

In you're case, I think it cannot simply find the fun_test:run/1 function.