Profiler v0.1.0 Profiler View Source

This sampling profiler is intendend for shell and remote shell usage. Most commands here print their results to the screen for human inspection.

Example usage:

iex(2)> Profiler.profile("<0.187.0>")
100% {:proc_lib, :init_p_do_apply, 3, [file: 'proc_lib.erl', line: 249]}
  100% {IEx.Evaluator, :init, 4, [file: 'lib/iex/evaluator.ex', line: 27]}
    100% {IEx.Evaluator, :loop, 1, [file: 'lib/iex/evaluator.ex', line: 103]}
        100% {IEx.Evaluator, :eval, 3, [file: 'lib/iex/evaluator.ex', line: 217]}
          100% {IEx.Evaluator, :do_eval, 3, [file: 'lib/iex/evaluator.ex', line: 239]}
              100% {IEx.Evaluator, :handle_eval, 5, [file: 'lib/iex/evaluator.ex', line: 258]}
                100% {:elixir, :eval_forms, 3, [file: 'src/elixir.erl', line: 263]}
                    100% {:elixir, :recur_eval, 3, [file: 'src/elixir.erl', line: 278]}
                      100% {:erl_eval, :do_apply, 6, [file: 'erl_eval.erl', line: 680]}
                          100% {Profiler, :profile, 2, [file: 'lib/profiler.ex', line: 120]}
                            100% {Enum, :reduce_range_inc, 4, [file: 'lib/enum.ex', line: 3371]}
                                100% {Profiler, :"-profile/2-fun-0-", 3, [file: 'lib/profiler.ex', line: 121]}

Link to this section Summary

Functions

Processes lists all processes ordered by reductions withing the given timeout. For that it takes an initial snapshot, sleeps the given timeout and takes a second snapshot.

This runs the sampling profiler for the given amount of milliseconds or 10 seconds by default. The sampling profiler will collect stack traces of the given process pid or process name and print the collected samples based on frequency.

Arguments are the same as for profile() but this sampling profiler does not analyze stacktrace but instead just samples the current function and prints the result.

Times the given function and prints the result. Example usage

Link to this section Functions

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processes(timeout \\ 5000)

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processes(:infinity | non_neg_integer()) :: :ok

Processes lists all processes ordered by reductions withing the given timeout. For that it takes an initial snapshot, sleeps the given timeout and takes a second snapshot.

  iex(1)> Profiler.processes
  [<0.187.0>,{'Elixir.IEx.Evaluator',init,4},1339]
  [<0.132.0>,tls_client_ticket_store,32]
  [<0.182.0>,{'Elixir.Logger.Watcher',init,1},1]
  [<0.181.0>,'Elixir.Logger.BackendSupervisor',1]
  [<0.180.0>,{'Elixir.Logger.Watcher',init,1},1]
  [<0.179.0>,'Elixir.Logger',1]
  [<0.178.0>,'Elixir.Logger.Supervisor',1]
  [<0.177.0>,{application_master,start_it,4},1]
  [<0.176.0>,{application_master,init,4},1]
  [<0.161.0>,'Elixir.Hex.UpdateChecker',1]
  :ok
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profile(pid, n \\ 10000)

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profile(String.t() | atom() | pid(), integer()) :: :ok

This runs the sampling profiler for the given amount of milliseconds or 10 seconds by default. The sampling profiler will collect stack traces of the given process pid or process name and print the collected samples based on frequency.

For pid there are three different input formats allowed:

  1. Native pid()
  2. An atom that is resolved using whereis(name)
  3. A string of the format "" or "0.b.c" or just "b" in which case the pid is interpreted as "<0.b.0>" 4 An integer, in which case the pid is interpreted as "<0.#{int}.0>"

    In this example the profiler is used to profile itself. The first percentage number shows how many samples were found in the given function call. Indention indicates the call stack:

  iex(2)> Profiler.profile(187)
  100% {:proc_lib, :init_p_do_apply, 3, [file: 'proc_lib.erl', line: 249]}
    100% {IEx.Evaluator, :init, 4, [file: 'lib/iex/evaluator.ex', line: 27]}
      100% {IEx.Evaluator, :loop, 1, [file: 'lib/iex/evaluator.ex', line: 103]}
          100% {IEx.Evaluator, :eval, 3, [file: 'lib/iex/evaluator.ex', line: 217]}
            100% {IEx.Evaluator, :do_eval, 3, [file: 'lib/iex/evaluator.ex', line: 239]}
                100% {IEx.Evaluator, :handle_eval, 5, [file: 'lib/iex/evaluator.ex', line: 258]}
                  100% {:elixir, :eval_forms, 3, [file: 'src/elixir.erl', line: 263]}
                      100% {:elixir, :recur_eval, 3, [file: 'src/elixir.erl', line: 278]}
                        100% {:erl_eval, :do_apply, 6, [file: 'erl_eval.erl', line: 680]}
                            100% {Profiler, :profile, 2, [file: 'lib/profiler.ex', line: 120]}
                              100% {Enum, :reduce_range_inc, 4, [file: 'lib/enum.ex', line: 3371]}
                                  100% {Profiler, :"-profile/2-fun-0-", 3, [file: 'lib/profiler.ex', line: 121]}
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profile_simple(pid, n \\ 10000)

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profile_simple(any(), integer()) :: :ok

Arguments are the same as for profile() but this sampling profiler does not analyze stacktrace but instead just samples the current function and prints the result.

The first number shows the total number of samples that have been recorded per function call.

  iex(2)> Profiler.profile_simple 197
  {10000, {Profiler, :"-profile_simple/2-fun-0-", 3}}
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time(fun, msg \\ "timer")

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time((... -> any()), String.t()) :: any()

Times the given function and prints the result. Example usage:

  iex(1)> Profiler.time(fn() -> Process.sleep 1000 end)
  timer: 1004
  :ok