From 6487aac5977cf470bc6a2cd0964da2850ee38717 Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Thu, 30 Oct 2014 23:57:01 +0100 Subject: Introduce a new time API The old time API is based on erlang:now/0. The major issue with erlang:now/0 is that it was intended to be used for so many unrelated things. This tied these unrelated operations together and unnecessarily caused performance, scalability as well as accuracy, and precision issues for operations that do not need to have such issues. The new API spreads different functionality over multiple functions in order to improve on this. The new API consists of a number of new BIFs: - erlang:convert_time_unit/3 - erlang:monotonic_time/0 - erlang:monotonic_time/1 - erlang:system_time/0 - erlang:system_time/1 - erlang:time_offset/0 - erlang:time_offset/1 - erlang:timestamp/0 - erlang:unique_integer/0 - erlang:unique_integer/1 - os:system_time/0 - os:system_time/1 and a number of extensions of existing BIFs: - erlang:monitor(time_offset, clock_service) - erlang:system_flag(time_offset, finalize) - erlang:system_info(os_monotonic_time_source) - erlang:system_info(time_offset) - erlang:system_info(time_warp_mode) - erlang:system_info(time_correction) - erlang:system_info(start_time) See the "Time and Time Correction in Erlang" chapter of the ERTS User's Guide for more information. --- lib/stdlib/src/otp_internal.erl | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'lib/stdlib') diff --git a/lib/stdlib/src/otp_internal.erl b/lib/stdlib/src/otp_internal.erl index 6c25beabe9..0c59af621d 100644 --- a/lib/stdlib/src/otp_internal.erl +++ b/lib/stdlib/src/otp_internal.erl @@ -59,6 +59,11 @@ obsolete_1(erl_eval, arg_list, 3) -> obsolete_1(erlang, hash, 2) -> {deprecated, {erlang, phash2, 2}}; +obsolete_1(erlang, now, 0) -> + {deprecated, + "Deprecated BIF. See the \"Time and Time Correction in Erlang\" " + "chapter of the ERTS User's Guide for more information."}; + obsolete_1(calendar, local_time_to_universal_time, 1) -> {deprecated, {calendar, local_time_to_universal_time_dst, 1}}; -- cgit v1.2.3 From fbaa0becc787e73fa539e0d497b0d74be27c9534 Mon Sep 17 00:00:00 2001 From: Rickard Green Date: Wed, 17 Dec 2014 22:18:27 +0100 Subject: Replace usage of erlang:now() with usage of new API --- lib/stdlib/doc/src/calendar.xml | 6 ++++-- lib/stdlib/doc/src/file_sorter.xml | 6 +++--- lib/stdlib/doc/src/random.xml | 9 ++++----- lib/stdlib/doc/src/timer.xml | 10 ++++++---- lib/stdlib/src/calendar.erl | 2 +- lib/stdlib/src/dets.erl | 22 ++++++++++++++-------- lib/stdlib/src/dets_utils.erl | 2 +- lib/stdlib/src/erl_tar.erl | 2 +- lib/stdlib/src/escript.erl | 8 +++++--- lib/stdlib/src/file_sorter.erl | 4 ++-- lib/stdlib/src/qlc.erl | 4 ++-- lib/stdlib/src/random.erl | 8 +++++++- lib/stdlib/src/stdlib.app.src | 2 +- lib/stdlib/src/supervisor.erl | 17 ++--------------- lib/stdlib/src/timer.erl | 6 ++---- 15 files changed, 55 insertions(+), 53 deletions(-) (limited to 'lib/stdlib') diff --git a/lib/stdlib/doc/src/calendar.xml b/lib/stdlib/doc/src/calendar.xml index e32a639b81..d8193a9ec2 100644 --- a/lib/stdlib/doc/src/calendar.xml +++ b/lib/stdlib/doc/src/calendar.xml @@ -270,7 +270,8 @@ Convert now to local date and time

This function returns local date and time converted from - the return value from erlang:now().

+ the return value from + erlang:timestamp/0.

 @@ -279,7 +280,8 @@ Convert now to date and time

This function returns Universal Coordinated Time (UTC) - converted from the return value from erlang:now().

+ converted from the return value from + erlang:timestamp/0.

 diff --git a/lib/stdlib/doc/src/file_sorter.xml b/lib/stdlib/doc/src/file_sorter.xml index 16572df3c5..c069333c29 100644 --- a/lib/stdlib/doc/src/file_sorter.xml +++ b/lib/stdlib/doc/src/file_sorter.xml @@ -105,9 +105,9 @@ file:get_cwd() is used instead. The names of temporary files are derived from the Erlang nodename (node()), the process identifier of the current Erlang - emulator (os:getpid()), and a timestamp - (erlang:now()); a typical name would be - fs_mynode@myhost_1763_1043_337000_266005.17, where + emulator (os:getpid()), and a unique integer + (erlang:unique_integer([positive])); a typical name would be + fs_mynode@myhost_1763_4711.17, where 17 is a sequence number. Existing files will be overwritten. Temporary files are deleted unless some uncaught EXIT signal occurs. diff --git a/lib/stdlib/doc/src/random.xml b/lib/stdlib/doc/src/random.xml index e001058e19..2cc621ffc3 100644 --- a/lib/stdlib/doc/src/random.xml +++ b/lib/stdlib/doc/src/random.xml @@ -70,12 +70,11 @@

Seeds random number generation with integer values in the process dictionary, and returns the old state.

-

One way of obtaining a seed is to use the BIF now/0:

+

One easy way of obtaining a unique value to seed with is to:

- ... - {A1,A2,A3} = now(), - random:seed(A1, A2, A3), - ... + random:seed(erlang:phash2([node()]), + erlang:monotonic_time(), + erlang:unique_integer()) diff --git a/lib/stdlib/doc/src/timer.xml b/lib/stdlib/doc/src/timer.xml index eca9a72d36..791a29689e 100644 --- a/lib/stdlib/doc/src/timer.xml +++ b/lib/stdlib/doc/src/timer.xml @@ -217,12 +217,14 @@ - Calculate time difference between now/0timestamps + Calculate time difference between timestamps In microseconds

Calculates the time difference Tdiff = T2 - T1 in - microseconds, where T1 and T2 probably - are timestamp tuples returned from erlang:now/0.

+ microseconds, where T1 and T2 + are timestamp tuples on the same format as returned from + erlang:timestamp/0, + or os:timestamp/0.

 @@ -234,7 +236,7 @@ - Converts Minutesto Milliseconds. + Converts Minutes to Milliseconds.

Return the number of milliseconds in Minutes.

 diff --git a/lib/stdlib/src/calendar.erl b/lib/stdlib/src/calendar.erl index 0320e0cd0e..d08001c933 100644 --- a/lib/stdlib/src/calendar.erl +++ b/lib/stdlib/src/calendar.erl @@ -299,7 +299,7 @@ local_time_to_universal_time_dst(DateTime) -> %% now_to_universal_time(Now) %% now_to_datetime(Now) %% -%% Convert from now() to UTC. +%% Convert from erlang:timestamp() to UTC. %% %% Args: Now = now(); now() = {MegaSec, Sec, MilliSec}, MegaSec = Sec %% = MilliSec = integer() diff --git a/lib/stdlib/src/dets.erl b/lib/stdlib/src/dets.erl index a4bd45ea19..5d365ac962 100644 --- a/lib/stdlib/src/dets.erl +++ b/lib/stdlib/src/dets.erl @@ -1963,7 +1963,7 @@ do_safe_fixtable(Head, Pid, true) -> case Head#head.fixed of false -> link(Pid), - Fixed = {erlang:now(), [{Pid, 1}]}, + Fixed = {utime_now(), [{Pid, 1}]}, Ftab = dets_utils:get_freelists(Head), Head#head{fixed = Fixed, freelists = {Ftab, Ftab}}; {TimeStamp, Counters} -> @@ -3088,14 +3088,14 @@ update_cache(Head, ToAdd) -> {Head1, Found, []}; Cache#cache.wrtime =:= undefined -> %% Empty cache. Schedule a delayed write. - Now = now(), Me = self(), + Now = time_now(), Me = self(), Call = ?DETS_CALL(Me, {delayed_write, Now}), erlang:send_after(Cache#cache.delay, Me, Call), {Head1#head{cache = NewCache#cache{wrtime = Now}}, Found, []}; Size0 =:= 0 -> %% Empty cache that has been written after the %% currently scheduled delayed write. - {Head1#head{cache = NewCache#cache{wrtime = now()}}, Found, []}; + {Head1#head{cache = NewCache#cache{wrtime = time_now()}}, Found, []}; true -> %% Cache is not empty, delayed write has been scheduled. {Head1, Found, []} @@ -3158,11 +3158,7 @@ delayed_write(Head, WrTime) -> Head#head{cache = NewCache}; true -> %% Yes, schedule a new delayed write. - {MS1,S1,M1} = WrTime, - {MS2,S2,M2} = LastWrTime, - WrT = M1+1000000*(S1+1000000*MS1), - LastWrT = M2+1000000*(S2+1000000*MS2), - When = round((LastWrT - WrT)/1000), Me = self(), + When = round((LastWrTime - WrTime)/1000), Me = self(), Call = ?DETS_CALL(Me, {delayed_write, LastWrTime}), erlang:send_after(When, Me, Call), Head @@ -3274,6 +3270,16 @@ err(Error) -> Error end. +-compile({inline, [time_now/0]}). +time_now() -> + erlang:monotonic_time(1000000). + +-compile({inline, [utime_now/0]}). +utime_now() -> + Time = time_now(), + UniqueCounter = erlang:unique_integer([monotonic]), + {Time, UniqueCounter}. + %%%%%%%%%%%%%%%%% DEBUG functions %%%%%%%%%%%%%%%% file_info(FileName) -> diff --git a/lib/stdlib/src/dets_utils.erl b/lib/stdlib/src/dets_utils.erl index 6c176ad513..26e22dbd5b 100644 --- a/lib/stdlib/src/dets_utils.erl +++ b/lib/stdlib/src/dets_utils.erl @@ -447,7 +447,7 @@ reset_cache(C) -> WrTime =:= undefined -> WrTime; true -> - now() + erlang:monotonic_time(1000000) end, PK = family(C#cache.cache), NewC = C#cache{cache = [], csize = 0, inserts = 0, wrtime = NewWrTime}, diff --git a/lib/stdlib/src/erl_tar.erl b/lib/stdlib/src/erl_tar.erl index caa3276d09..72bd54fa29 100644 --- a/lib/stdlib/src/erl_tar.erl +++ b/lib/stdlib/src/erl_tar.erl @@ -300,7 +300,7 @@ format_error(Term) -> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% add1(TarFile, Bin, NameInArchive, Opts) when is_binary(Bin) -> - Now = calendar:now_to_local_time(now()), + Now = calendar:now_to_local_time(erlang:timestamp()), Info = #file_info{size = byte_size(Bin), type = regular, access = read_write, diff --git a/lib/stdlib/src/escript.erl b/lib/stdlib/src/escript.erl index 6bd0eb8a22..90e1f3a8d6 100644 --- a/lib/stdlib/src/escript.erl +++ b/lib/stdlib/src/escript.erl @@ -663,7 +663,8 @@ check_source(S, CheckOnly) -> end. pre_def_macros(File) -> - {MegaSecs, Secs, MicroSecs} = erlang:now(), + {MegaSecs, Secs, MicroSecs} = erlang:timestamp(), + Unique = erlang:unique_integer([positive]), Replace = fun(Char) -> case Char of $\. -> $\_; @@ -675,8 +676,9 @@ pre_def_macros(File) -> CleanBase ++ "__" ++ "escript__" ++ integer_to_list(MegaSecs) ++ "__" ++ - integer_to_list(Secs) ++ "__" ++ - integer_to_list(MicroSecs), + integer_to_list(Secs) ++ "__" ++ + integer_to_list(MicroSecs) ++ "__" ++ + integer_to_list(Unique), Module = list_to_atom(ModuleStr), PreDefMacros = [{'MODULE', Module, redefine}, {'MODULE_STRING', ModuleStr, redefine}], diff --git a/lib/stdlib/src/file_sorter.erl b/lib/stdlib/src/file_sorter.erl index 687d72b4bd..61b489513a 100644 --- a/lib/stdlib/src/file_sorter.erl +++ b/lib/stdlib/src/file_sorter.erl @@ -1425,8 +1425,8 @@ tmp_prefix1(Dir, TmpDirOpt) -> U = "_", Node = node(), Pid = os:getpid(), - {MSecs,Secs,MySecs} = now(), - F = lists:concat(["fs_",Node,U,Pid,U,MSecs,U,Secs,U,MySecs,"."]), + Unique = erlang:unique_integer([positive]), + F = lists:concat(["fs_",Node,U,Pid,U,Unique,"."]), TmpDir = case TmpDirOpt of default -> Dir; diff --git a/lib/stdlib/src/qlc.erl b/lib/stdlib/src/qlc.erl index 002032d48d..5b19ee6190 100644 --- a/lib/stdlib/src/qlc.erl +++ b/lib/stdlib/src/qlc.erl @@ -2764,8 +2764,8 @@ tmp_filename(TmpDirOpt) -> U = "_", Node = node(), Pid = os:getpid(), - {MSecs,Secs,MySecs} = erlang:now(), - F = lists:concat([?MODULE,U,Node,U,Pid,U,MSecs,U,Secs,U,MySecs]), + Unique = erlang:unique_integer(), + F = lists:concat([?MODULE,U,Node,U,Pid,U,Unique]), TmpDir = case TmpDirOpt of "" -> {ok, CurDir} = file:get_cwd(), diff --git a/lib/stdlib/src/random.erl b/lib/stdlib/src/random.erl index d7b51a151c..cf84f8cecf 100644 --- a/lib/stdlib/src/random.erl +++ b/lib/stdlib/src/random.erl @@ -57,11 +57,17 @@ seed() -> %% seed({A1, A2, A3}) %% Seed random number generation --spec seed({A1, A2, A3}) -> 'undefined' | ran() when +-spec seed(SValue) -> 'undefined' | ran() when + SValue :: {A1, A2, A3} | integer(), A1 :: integer(), A2 :: integer(), A3 :: integer(). +seed(Int) when is_integer(Int) -> + A1 = (Int bsr 16) band 16#fffffff, + A2 = Int band 16#ffffff, + A3 = (Int bsr 36) bor (A2 bsr 16), + seed(A1, A2, A3); seed({A1, A2, A3}) -> seed(A1, A2, A3). diff --git a/lib/stdlib/src/stdlib.app.src b/lib/stdlib/src/stdlib.app.src index aa9899da3b..5edcc28418 100644 --- a/lib/stdlib/src/stdlib.app.src +++ b/lib/stdlib/src/stdlib.app.src @@ -103,7 +103,7 @@ dets]}, {applications, [kernel]}, {env, []}, - {runtime_dependencies, ["sasl-2.4","kernel-3.0.2","erts-6.2","crypto-3.3", + {runtime_dependencies, ["sasl-2.4","kernel-3.0.2","erts-7.0","crypto-3.3", "compiler-5.0"]} ]}. diff --git a/lib/stdlib/src/supervisor.erl b/lib/stdlib/src/supervisor.erl index ede2742875..4979179b5c 100644 --- a/lib/stdlib/src/supervisor.erl +++ b/lib/stdlib/src/supervisor.erl @@ -1312,7 +1312,7 @@ add_restart(State) -> I = State#state.intensity, P = State#state.period, R = State#state.restarts, - Now = erlang:now(), + Now = erlang:monotonic_time(1), R1 = add_restart([Now|R], Now, P), State1 = State#state{restarts = R1}, case length(R1) of @@ -1333,26 +1333,13 @@ add_restart([], _, _) -> []. inPeriod(Time, Now, Period) -> - case difference(Time, Now) of + case Time - Now of T when T > Period -> false; _ -> true end. -%% -%% Time = {MegaSecs, Secs, MicroSecs} (NOTE: MicroSecs is ignored) -%% Calculate the time elapsed in seconds between two timestamps. -%% If MegaSecs is equal just subtract Secs. -%% Else calculate the Mega difference and add the Secs difference, -%% note that Secs difference can be negative, e.g. -%% {827, 999999, 676} diff {828, 1, 653753} == > 2 secs. -%% -difference({TimeM, TimeS, _}, {CurM, CurS, _}) when CurM > TimeM -> - ((CurM - TimeM) * 1000000) + (CurS - TimeS); -difference({_, TimeS, _}, {_, CurS, _}) -> - CurS - TimeS. - %%% ------------------------------------------------------ %%% Error and progress reporting. %%% ------------------------------------------------------ diff --git a/lib/stdlib/src/timer.erl b/lib/stdlib/src/timer.erl index 72a2dd9616..19d803345e 100644 --- a/lib/stdlib/src/timer.erl +++ b/lib/stdlib/src/timer.erl @@ -437,10 +437,8 @@ positive(X) -> %% %% system_time() -> time in microseconds %% -system_time() -> - {M,S,U} = erlang:now(), - 1000000 * (M*1000000 + S) + U. - +system_time() -> + erlang:monotonic_time(1000000). send([Pid, Msg]) -> Pid ! Msg. -- cgit v1.2.3