[erlang-questions] I'm having a SNAFU moment: timer:sleep/1

[Roberto Ostinelli]

Thank you Imants.
Indeed, timer:apply_interval/4 actually works perfectly, no timer
weirdness. I guess the implementation is not depending on the normal
receive..after..end loop.

For others interested, here's a working code example:

-module(test).
-export([call_periodical/2]).
-export([periodical_fun/1]).

call_periodical(Num, IntervalMs) ->
Start = epoch_time_ms(),
{ok, TRef} = timer:apply_interval(IntervalMs, ?MODULE, periodical_fun,
[self()]),
wait(Num),
io:format("Finished in ~p microseconds.~n", [epoch_time_ms() - Start]),
timer:cancel(TRef).

wait(0) -> ok;
wait(Num) ->
receive
ok -> wait(Num - 1);
_ -> ok
end.

periodical_fun(Pid) ->
Pid ! ok.

epoch_time_ms() ->
    {Mega, Sec, Micro} = os:timestamp(),
    (Mega * 1000000 + Sec) * 1000 + round(Micro / 1000).


Running it:

Erlang/OTP 17 [erts-6.3] [source] [64-bit] [smp:8:8] [async-threads:10]
[hipe] [kernel-poll:false] [dtrace]

Eshell V6.3  (abort with ^G)
1> c(test).
{ok,test}
2> test:call_periodical(1000, 10).
Finished in 10004 microseconds.
{ok,cancel}
3> test:call_periodical(2000, 10).
Finished in 20002 microseconds.
{ok,cancel}
4> test:call_periodical(10000, 1).
Finished in 10002 microseconds.
{ok,cancel}
5> test:call_periodical(20000, 1).
Finished in 20000 microseconds.
{ok,cancel}
6> test:call_periodical(1000, 1).
Finished in 1002 microseconds.
{ok,cancel}

Where everything works as expected.

Thank you everyone!

Best,
r.


On Mon, Jan 12, 2015 at 6:14 PM, Imants Cekusins <imantc@REDACTED> wrote:

> btw CPU looked ok: was spread across cores and did not max out.
>
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