diff options
Diffstat (limited to 'lib/stdlib')
| -rw-r--r-- | lib/stdlib/doc/src/timer.xml | 24 | ||||
| -rw-r--r-- | lib/stdlib/src/timer.erl | 13 | ||||
| -rw-r--r-- | lib/stdlib/test/timer_simple_SUITE.erl | 18 |
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, |