File 5421-stdlib-timer-better-resolution-control.patch of Package erlang

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File 5421-stdlib-timer-better-resolution-control.patch of Package erlang (Revision 44e4c85c443d6ffa7f431d0afb733176)

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From a2265b5d9ccbdf866be5eaf583eaf683e19d4893 Mon Sep 17 00:00:00 2001
From: jdamanalo <jamanalo5@up.edu.ph>
Date: Thu, 24 Nov 2022 21:01:26 +0800
Subject: [PATCH 1/2] stdlib/timer: better resolution control - added a final
 `erlang:time_unit()` argument to `tc/[1,2,3]`

Tackles #3264. Primarily for systems with worse resolution than a microsecond.
---
 lib/stdlib/doc/src/timer.xml           | 41 ++++++++++++++++-----
 lib/stdlib/src/timer.erl               | 50 ++++++++++++++++++++------
 lib/stdlib/test/timer_simple_SUITE.erl | 13 +++++++
 3 files changed, 85 insertions(+), 19 deletions(-)

diff --git a/lib/stdlib/doc/src/timer.xml b/lib/stdlib/doc/src/timer.xml
index 2cbf7977a9..6f3aef8c7e 100644
--- a/lib/stdlib/doc/src/timer.xml
+++ b/lib/stdlib/doc/src/timer.xml
@@ -319,14 +319,37 @@
 
 <func>
 <name name="tc" arity="1" since="OTP R14B03"/>
- <name name="tc" arity="2" since="OTP R14B"/>
- <name name="tc" arity="3" since=""/>
+ <name name="tc" arity="2" clause_i="1" since="OTP R14B"/>
+ <name name="tc" arity="3" clause_i="1" since=""/>
+ <fsummary>Measure the real time it takes to evaluate <c>Fun</c>.</fsummary>
+ <desc>
+ <taglist>
+ <tag><c>tc/3</c></tag>
+ <item>
+ Calls function <c>timer:tc(Module, Function, Arguments, microsecond)</c>.
+ </item>
+ <tag><c>tc/2</c></tag>
+ <item>
+ Calls function <c>timer:tc(Fun, Arguments, microsecond)</c>.
+ </item>
+ <tag><c>tc/1</c></tag>
+ <item>
+ Calls function <c>timer:tc(Fun, microsecond)</c>.
+ </item>
+ </taglist>
+ </desc>
+ </func>
+
+ <func>
+ <name name="tc" arity="2" clause_i="2" since=""/>
+ <name name="tc" arity="3" clause_i="2" since=""/>
+ <name name="tc" arity="4" since=""/>
 <fsummary>Measure the real time it takes to evaluate <c>apply(Module,
 Function, Arguments)</c> or <c>apply(Fun, Arguments)</c>.</fsummary>
- <type_desc variable="Time">In microseconds</type_desc>
+ <type_desc variable="Time">In the specified <c>TimeUnit</c></type_desc>
 <desc>
 <taglist>
- <tag><c>tc/3</c></tag>
+ <tag><c>tc/4</c></tag>
 <item>
 Evaluates <c>apply(<anno>Module</anno>, <anno>Function</anno>,
 <anno>Arguments</anno>)</c> and measures the elapsed real time as 
@@ -334,18 +357,18 @@
 <c>erlang:monotonic_time/0</c></seemfa>.
 Returns <c>{<anno>Time</anno>, <anno>Value</anno>}</c>, where
 <c><anno>Time</anno></c> is the elapsed real time in
- microseconds, and <c><anno>Value</anno></c> is what is
+ the specified <c>TimeUnit</c>, and <c><anno>Value</anno></c> is what is
 returned from the apply.
 </item>
- <tag><c>tc/2</c></tag>
+ <tag><c>tc/3</c></tag>
 <item>
 Evaluates <c>apply(<anno>Fun</anno>, <anno>Arguments</anno>)</c>.
- Otherwise the same as <c>tc/3</c>.
+ Otherwise the same as <c>tc/4</c>.
 </item>
- <tag><c>tc/1</c></tag>
+ <tag><c>tc/2</c></tag>
 <item>
 Evaluates <c><anno>Fun</anno>()</c>. Otherwise the same as
- <c>tc/2</c>.
+ <c>tc/3</c>.
 </item>
 </taglist>
 </desc>
diff --git a/lib/stdlib/src/timer.erl b/lib/stdlib/src/timer.erl
index 780ae4c7f1..17c12f2931 100644
--- a/lib/stdlib/src/timer.erl
+++ b/lib/stdlib/src/timer.erl
@@ -24,7 +24,7 @@
 	 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/1, tc/2, tc/3, now_diff/2,
+ cancel/1, sleep/1, tc/1, tc/2, tc/3, tc/4, now_diff/2,
 	 seconds/1, minutes/1, hours/1, hms/3]).
 
 -export([start_link/0, start/0,
@@ -247,41 +247,71 @@ sleep(T) ->
 Time :: integer(),
 Value :: term().
 tc(F) ->
+ tc(F, microsecond).
+
+%%
+%% Measure the execution time (in microseconds) for Fun(Args)
+%% or the execution time (in TimeUnit) for Fun().
+%%
+-spec tc(Fun, Arguments) -> {Time, Value}
+ when Fun :: function(),
+ Arguments :: [term()],
+ Time :: integer(),
+ Value :: term();
+ (Fun, TimeUnit) -> {Time, Value}
+ when Fun :: function(),
+ TimeUnit :: erlang:time_unit(),
+ Time :: integer(),
+ Value :: term().
+tc(F, A) when is_list(A) ->
+ tc(F, A, microsecond);
+tc(F, TimeUnit) ->
 T1 = erlang:monotonic_time(),
 Val = F(),
 T2 = erlang:monotonic_time(),
- Time = erlang:convert_time_unit(T2 - T1, native, microsecond),
+ Time = erlang:convert_time_unit(T2 - T1, native, TimeUnit),
 {Time, Val}.
 
 %%
-%% Measure the execution time (in microseconds) for Fun(Args).
+%% Measure the execution time (in microseconds) for an MFA
+%% or the execution time (in TimeUnit) for Fun(Args).
 %%
--spec tc(Fun, Arguments) -> {Time, Value}
+-spec tc(Module, Function, Arguments) -> {Time, Value}
+ when Module :: module(),
+ Function :: atom(),
+ Arguments :: [term()],
+ Time :: integer(),
+ Value :: term();
+ (Fun, Arguments, TimeUnit) -> {Time, Value}
 when Fun :: function(),
 Arguments :: [term()],
+ TimeUnit :: erlang:time_unit(),
 Time :: integer(),
 Value :: term().
-tc(F, A) ->
+tc(M, F, A) when is_list(A) ->
+ tc(M, F, A, microsecond);
+tc(F, A, TimeUnit) ->
 T1 = erlang:monotonic_time(),
 Val = apply(F, A),
 T2 = erlang:monotonic_time(),
- Time = erlang:convert_time_unit(T2 - T1, native, microsecond),
+ Time = erlang:convert_time_unit(T2 - T1, native, TimeUnit),
 {Time, Val}.
 
 %%
-%% Measure the execution time (in microseconds) for an MFA.
+%% Measure the execution time (in TimeUnit) for an MFA.
 %%
--spec tc(Module, Function, Arguments) -> {Time, Value}
+-spec tc(Module, Function, Arguments, TimeUnit) -> {Time, Value}
 when Module :: module(),
 Function :: atom(),
 Arguments :: [term()],
+ TimeUnit :: erlang:time_unit(),
 Time :: integer(),
 Value :: term().
-tc(M, F, A) ->
+tc(M, F, A, TimeUnit) ->
 T1 = erlang:monotonic_time(),
 Val = apply(M, F, A),
 T2 = erlang:monotonic_time(),
- Time = erlang:convert_time_unit(T2 - T1, native, microsecond),
+ Time = erlang:convert_time_unit(T2 - T1, native, TimeUnit),
 {Time, Val}.
 
 %%
diff --git a/lib/stdlib/test/timer_simple_SUITE.erl b/lib/stdlib/test/timer_simple_SUITE.erl
index 9031a2d242..761689dc51 100644
--- a/lib/stdlib/test/timer_simple_SUITE.erl
+++ b/lib/stdlib/test/timer_simple_SUITE.erl
@@ -731,7 +731,19 @@ tc(Config) when is_list(Config) ->
 		 true -> ok
 		end,
 
+ %% tc/4
+ {Res4, ok} = timer:tc(timer, sleep, [500], millisecond),
+ ok = if
+ Res4 < 500 -> {too_early, Res4};
+ Res4 > 800 -> {too_late, Res4};
+ true -> ok
+ end,
+
 %% Check that timer:tc don't catch errors
+ ok = try timer:tc(erlang, exit, [foo], second)
+ catch exit:foo -> ok
+ end,
+
 ok = try timer:tc(erlang, exit, [foo])
 	 catch exit:foo -> ok
 	 end,
@@ -746,6 +758,7 @@ tc(Config) when is_list(Config) ->
 
 %% Check that return values are propageted
 Self = self(),
+ {_, Self} = timer:tc(erlang, self, [], second),
 {_, Self} = timer:tc(erlang, self, []),
 {_, Self} = timer:tc(fun(P) -> P end, [self()]),
 {_, Self} = timer:tc(fun() -> self() end),
-- 
2.35.3

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File 5421-stdlib-timer-better-resolution-control.patch of Package erlang (Revision 44e4c85c443d6ffa7f431d0afb733176)

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