Testing the use of inspect/1 with a function yielding an integer

benchee_output.txt

Operating System: macOS"
CPU Information: Intel(R) Core(TM) i7-3840QM CPU @ 2.80GHz
Number of Available Cores: 8
Available memory: 16 GB
Elixir 1.6.4
Erlang 20.3.4

Benchmark suite executing with the following configuration:
warmup: 2 s
time: 5 s
memory time: 0 μs
parallel: 1
inputs: none specified
Estimated total run time: 28 s


Benchmarking with_inspect...
Benchmarking with_integer_tostring...
Benchmarking with_tostring...
Benchmarking without_inspect...

Name                            ips        average  deviation         median         99th %
without_inspect                0.62         1.60 s     ±6.29%         1.57 s         1.74 s
with_integer_tostring          0.41         2.44 s     ±5.14%         2.44 s         2.53 s
with_tostring                  0.35         2.83 s     ±1.60%         2.83 s         2.86 s
with_inspect                 0.0868        11.52 s     ±0.00%        11.52 s        11.52 s

Comparison:
without_inspect                0.62
with_integer_tostring          0.41 - 1.53x slower
with_tostring                  0.35 - 1.77x slower
with_inspect                 0.0868 - 7.20x slower

inspect_time.exs

bench_list = Enum.to_list(1..10_000_000)
with_inspect = fn (_) -> inspect(System.system_time(:seconds)) end
without_inspect = fn (_) -> System.system_time(:seconds) end
with_tostring = fn (_) -> to_string(System.system_time(:seconds)) end
with_integer_tostring = fn (_) -> Integer.to_string(System.system_time(:seconds)) end

Benchee.run(%{
  "with_inspect" => fn -> Enum.each(bench_list, with_inspect) end,
  "without_inspect" => fn -> Enum.each(bench_list, without_inspect) end,
  "with_tostring" => fn -> Enum.each(bench_list, with_tostring) end,
  "with_integer_tostring" => fn -> Enum.each(bench_list, with_integer_tostring) end
})

naive_timing.iex

iex(1)> s = System.monotonic_time(); Enum.each(1..10_000_000, fn (_) -> inspect(System.system_time(:seconds)) end); e = System.monotonic_time()
-576460634717908689
iex(2)> System.convert_time_unit((s - e), :native, :milliseconds)
-70257
iex(3)> System.convert_time_unit((e - s), :native, :milliseconds)
70256
iex(4)> s = System.monotonic_time(); Enum.each(1..10_000_000, fn (_) -> System.system_time(:seconds) end); e = System.monotonic_time()
-576460582237370153
iex(5)> System.convert_time_unit((e - s), :native, :milliseconds)
10412