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-rw-r--r--lib/stdlib/doc/src/timer.xml24
-rw-r--r--lib/stdlib/src/timer.erl13
-rw-r--r--lib/stdlib/test/timer_simple_SUITE.erl18
3 files changed, 44 insertions, 11 deletions
diff --git a/lib/stdlib/doc/src/timer.xml b/lib/stdlib/doc/src/timer.xml
index 0b6807dd6c..3d54047e35 100644
--- a/lib/stdlib/doc/src/timer.xml
+++ b/lib/stdlib/doc/src/timer.xml
@@ -202,18 +202,32 @@
</func>
<func>
<name>tc(Module, Function, Arguments) -> {Time, Value}</name>
- <fsummary>Measure the real time it takes to evaluate <c>apply(Module, Function, Arguments)</c></fsummary>
+ <name>tc(Fun, Arguments) -> {Time, Value}</name>
+ <fsummary>Measure the real time it takes to evaluate <c>apply(Module,
+ Function, Arguments)</c> or <c>apply(Fun, Arguments)</c></fsummary>
<type>
<v>Module = Function = atom()</v>
+ <v>Fun = fun()</v>
<v>Arguments = [term()]</v>
<v>Time = integer() in microseconds</v>
<v>Value = term()</v>
</type>
<desc>
- <p>Evaluates <c>apply(Module, Function, Arguments)</c> and measures
- the elapsed real time. Returns <c>{Time, Value}</c>, where
- <c>Time</c> is the elapsed real time in <em>microseconds</em>,
- and <c>Value</c> is what is returned from the apply.</p>
+ <p></p>
+ <taglist>
+ <tag><c>tc/3</c></tag>
+ <item>
+ <p>Evaluates <c>apply(Module, Function, Arguments)</c> and measures
+ the elapsed real time. Returns <c>{Time, Value}</c>, where
+ <c>Time</c> is the elapsed real time in <em>microseconds</em>,
+ and <c>Value</c> is what is returned from the apply.</p>
+ </item>
+ <tag><c>tc/2</c></tag>
+ <item>
+ <p>Evaluates <c>apply(Fun, Arguments)</c>. Otherwise works
+ like <c>tc/3</c>.</p>
+ </item>
+ </taglist>
</desc>
</func>
<func>
diff --git a/lib/stdlib/src/timer.erl b/lib/stdlib/src/timer.erl
index 36fdb48c75..12bbd45703 100644
--- a/lib/stdlib/src/timer.erl
+++ b/lib/stdlib/src/timer.erl
@@ -22,7 +22,7 @@
send_after/3, send_after/2,
exit_after/3, exit_after/2, kill_after/2, kill_after/1,
apply_interval/4, send_interval/3, send_interval/2,
- cancel/1, sleep/1, tc/3, now_diff/2,
+ cancel/1, sleep/1, tc/2, tc/3, now_diff/2,
seconds/1, minutes/1, hours/1, hms/3]).
-export([start_link/0, start/0,
@@ -98,6 +98,17 @@ sleep(T) ->
after T -> ok
end.
+
+%%
+%% Measure the execution time (in microseconds) for Fun(Args).
+%%
+-spec tc(function(), [_]) -> {time(), term()}.
+tc(F, A) ->
+ Before = erlang:now(),
+ Val = (catch apply(F, A)),
+ After = erlang:now(),
+ {now_diff(After, Before), Val}.
+
%%
%% Measure the execution time (in microseconds) for an MFA.
%%
diff --git a/lib/stdlib/test/timer_simple_SUITE.erl b/lib/stdlib/test/timer_simple_SUITE.erl
index 021a22c61b..6aa2b7b945 100644
--- a/lib/stdlib/test/timer_simple_SUITE.erl
+++ b/lib/stdlib/test/timer_simple_SUITE.erl
@@ -224,11 +224,19 @@ cancel2(Config) when is_list(Config) ->
tc(doc) -> "Test sleep/1 and tc/3.";
tc(suite) -> [];
tc(Config) when is_list(Config) ->
- % This should both sleep and tc
- ?line {Res, ok} = timer:tc(timer, sleep, [500]),
- ?line ok = if
- Res < 500*1000 -> {too_early, Res}; % Too early
- Res > 800*1000 -> {too_late, Res}; % Too much time
+ % This should both sleep and tc/3
+ ?line {Res1, ok} = timer:tc(timer, sleep, [500]),
+ ?line ok = if
+ Res1 < 500*1000 -> {too_early, Res1}; % Too early
+ Res1 > 800*1000 -> {too_late, Res1}; % Too much time
+ true -> ok
+ end,
+
+ % This should both sleep and tc/2
+ ?line {Res2, ok} = timer:tc(fun(T) -> timer:sleep(T) end, [500]),
+ ?line ok = if
+ Res2 < 500*1000 -> {too_early, Res2}; % Too early
+ Res2 > 800*1000 -> {too_late, Res2}; % Too much time
true -> ok
end,