Profiler return the return value of the function

lib/mix/lib/mix/tasks/profile.cprof.ex

@@ -157,6 +157,8 @@ defmodule Mix.Tasks.Profile.Cprof do
   @doc """
   Allows to programmatically run the `cprof` profiler on expression in `fun`.
 
+  Returns the return value of `fun`.
+
   ## Options
 
     * `:matching` - only profile calls matching the given pattern in form of
@@ -166,12 +168,15 @@ defmodule Mix.Tasks.Profile.Cprof do
     * `:module` - filters out any results not pertaining to the given module
 
   """
+  @spec profile((() -> any()), keyword()) :: any()
   def profile(fun, opts \\ []) when is_function(fun, 0) do
-    fun
-    |> profile_and_analyse(opts)
-    |> print_output
+    {return_value, num_matched_functions, analysis_result} = profile_and_analyse(fun, opts)
+
+    print_output(num_matched_functions, analysis_result)
 
     :cprof.stop()
+
+    return_value
   end
 
   defp profile_and_analyse(fun, opts) do
@@ -186,7 +191,7 @@ defmodule Mix.Tasks.Profile.Cprof do
         :error -> :cprof.start()
       end
 
-    apply(fun, [])
+    return_value = apply(fun, [])
 
     :cprof.pause()
 
@@ -209,19 +214,19 @@ defmodule Mix.Tasks.Profile.Cprof do
           end
       end
 
-    {num_matched_functions, analysis_result}
+    {return_value, num_matched_functions, analysis_result}
   end
 
   defp string_to_existing_module(":" <> module), do: String.to_existing_atom(module)
   defp string_to_existing_module(module), do: Module.concat([module])
 
-  defp print_output({num_matched_functions, {all_call_count, mod_analysis_list}}) do
+  defp print_output(num_matched_functions, {all_call_count, mod_analysis_list}) do
     print_total_row(all_call_count)
     Enum.each(mod_analysis_list, &print_analysis_result/1)
     print_number_of_matched_functions(num_matched_functions)
   end
 
-  defp print_output({num_matched_functions, {_mod, _call_count, _mod_fun_list} = mod_analysis}) do
+  defp print_output(num_matched_functions, {_mod, _call_count, _mod_fun_list} = mod_analysis) do
     print_analysis_result(mod_analysis)
     print_number_of_matched_functions(num_matched_functions)
   end

lib/mix/lib/mix/tasks/profile.eprof.ex

@@ -171,6 +171,8 @@ defmodule Mix.Tasks.Profile.Eprof do
   @doc """
   Allows to programmatically run the `eprof` profiler on expression in `fun`.
 
+  Returns the return value of `fun`.
+
   ## Options
 
     * `:matching` - only profile calls matching the given pattern in form of
@@ -181,10 +183,13 @@ defmodule Mix.Tasks.Profile.Eprof do
     * `:sort` - sort the results by `:time` or `:calls` (default: `:time`)
 
   """
+  @spec profile((() -> any()), keyword()) :: any()
   def profile(fun, opts \\ []) when is_function(fun, 0) do
-    fun
-    |> profile_and_analyse(opts)
-    |> print_output()
+    {return_value, results} = profile_and_analyse(fun, opts)
+
+    print_output(results)
+
+    return_value
   end
 
   defp profile_and_analyse(fun, opts) do
@@ -194,7 +199,7 @@ defmodule Mix.Tasks.Profile.Eprof do
     end
 
     :eprof.start()
-    :eprof.profile([], fun, Keyword.get(opts, :matching, {:_, :_, :_}))
+    {:ok, return_value} = :eprof.profile([], fun, Keyword.get(opts, :matching, {:_, :_, :_}))
 
     results =
       Enum.map(:eprof.dump(), fn {pid, call_results} ->
@@ -209,7 +214,7 @@ defmodule Mix.Tasks.Profile.Eprof do
 
     :eprof.stop()
 
-    results
+    {return_value, results}
   end
 
   defp filter_results(call_results, opts) do

lib/mix/lib/mix/tasks/profile.fprof.ex

@@ -166,17 +166,22 @@ defmodule Mix.Tasks.Profile.Fprof do
   @doc """
   Allows to programmatically run the `fprof` profiler on expression in `fun`.
 
+  Returns the return value of `fun`.
+
   ## Options
 
     * `:callers` - prints detailed information about immediate callers and called functions
     * `:details` - includes profile data for each profiled process
     * `:sort` - sorts the output by given key: `:acc` (default) or `:own`
 
   """
+  @spec profile((() -> any()), keyword()) :: any()
   def profile(fun, opts \\ []) when is_function(fun, 0) do
-    fun
-    |> profile_and_analyse(opts)
-    |> print_output
+    {return_value, analysis_output} = profile_and_analyse(fun, opts)
+
+    print_output(analysis_output)
+
+    return_value
   end
 
   defp profile_and_analyse(fun, opts) do
@@ -186,7 +191,7 @@ defmodule Mix.Tasks.Profile.Fprof do
     end
 
     {:ok, tracer} = :fprof.profile(:start)
-    :fprof.apply(fun, [], tracer: tracer)
+    return_value = :fprof.apply(fun, [], tracer: tracer)
 
     {:ok, analyse_dest} = StringIO.open("")
 
@@ -201,7 +206,7 @@ defmodule Mix.Tasks.Profile.Fprof do
     else
       :ok ->
         {_in, analysis_output} = StringIO.contents(analyse_dest)
-        String.to_charlist(analysis_output)
+        {return_value, String.to_charlist(analysis_output)}
     after
       StringIO.close(analyse_dest)
     end

lib/mix/test/mix/tasks/profile.cprof_test.exs

@@ -103,4 +103,12 @@ defmodule Mix.Tasks.Profile.CprofTest do
              end) =~ "Warmup..."
     end)
   end
+
+  describe ".profile/2" do
+    test "returns the return value of the function call" do
+      capture_io(fn ->
+        assert 42 == Cprof.profile(fn -> 42 end)
+      end)
+    end
+  end
 end

lib/mix/test/mix/tasks/profile.eprof_test.exs

@@ -112,4 +112,12 @@ defmodule Mix.Tasks.Profile.EprofTest do
              end) =~ "Warmup..."
     end)
   end
+
+  describe ".profile/2" do
+    test "returns the return value of the function call" do
+      capture_io(fn ->
+        assert 42 == Eprof.profile(fn -> 42 end)
+      end)
+    end
+  end
 end

lib/mix/test/mix/tasks/profile.fprof_test.exs

@@ -98,4 +98,12 @@ defmodule Mix.Tasks.Profile.FprofTest do
              end) =~ "Warmup..."
     end)
   end
+
+  describe ".profile/2" do
+    test "returns the return value of the function call" do
+      capture_io(fn ->
+        assert 42 == Fprof.profile(fn -> 42 end)
+      end)
+    end
+  end
 end