Merge branch 'bjorn/optimize-start-up/OTP-13368'

* bjorn/optimize-start-up/OTP-13368:
  Update preloaded modules
  init: Load modules in parallel using the new loader BIFs
  systools_make: Add commonly used modules to mandatory_modules/0
  compile: Pre-load compiler modules when invoked from 'erlc'

7 files changed, 263 insertions, 61 deletions

diff --git a/erts/preloaded/ebin/erl_prim_loader.beam b/erts/preloaded/ebin/erl_prim_loader.beam
index 6d777fa811..f224178c4f 100644
--- a/erts/preloaded/ebin/erl_prim_loader.beam
+++ b/erts/preloaded/ebin/erl_prim_loader.beam
diff --git a/erts/preloaded/ebin/init.beam b/erts/preloaded/ebin/init.beam
index 9d2dd38f3a..7d73ca2234 100644
--- a/erts/preloaded/ebin/init.beam
+++ b/erts/preloaded/ebin/init.beam
diff --git a/erts/preloaded/src/erl_prim_loader.erl b/erts/preloaded/src/erl_prim_loader.erl
index cbcced5512..641abae7b1 100644
--- a/erts/preloaded/src/erl_prim_loader.erl
+++ b/erts/preloaded/src/erl_prim_loader.erl
@@ -56,7 +56,7 @@
 -export([purge_archive_cache/0]).
 
 %% Used by init and the code server.
--export([get_modules/3]).
+-export([get_modules/2,get_modules/3]).
 
 -include_lib("kernel/include/file.hrl").
 
@@ -239,6 +239,13 @@ set_primary_archive(File, ArchiveBin, FileInfo, ParserFun)
 purge_archive_cache() ->
     request(purge_archive_cache).
 
+-spec get_modules([module()],
+		  fun((atom(), string(), binary()) ->
+			     {'ok',any()} | {'error',any()})) ->
+			 {'ok',{[any()],[any()]}}.
+
+get_modules(Modules, Fun) ->
+    request({get_modules,{Modules,Fun}}).
 
 -spec get_modules([module()],
 		  fun((atom(), string(), binary()) ->
@@ -338,6 +345,8 @@ handle_request(Req, Paths, St0) ->
 	    {{ok,Paths},St0};
 	{get_file,File} ->
 	    handle_get_file(St0, Paths, File);
+	{get_modules,{Modules,Fun}} ->
+	    handle_get_modules(St0, Modules, Fun, Paths);
 	{get_modules,{Modules,Fun,ModPaths}} ->
 	    handle_get_modules(St0, Modules, Fun, ModPaths);
 	{list_dir,Dir} ->
diff --git a/erts/preloaded/src/init.erl b/erts/preloaded/src/init.erl
index 5de3732c20..915f1183d6 100644
--- a/erts/preloaded/src/init.erl
+++ b/erts/preloaded/src/init.erl
@@ -297,9 +297,9 @@ crash(String, List) ->
 -spec boot_loop(pid(), state()) -> no_return().
 boot_loop(BootPid, State) ->
     receive
-	{BootPid,loaded,ModLoaded} ->
-	    Loaded = State#state.loaded,
-	    boot_loop(BootPid,State#state{loaded = [ModLoaded|Loaded]});
+	{BootPid,loaded,NewlyLoaded} ->
+	    Loaded = NewlyLoaded ++ State#state.loaded,
+	    boot_loop(BootPid, State#state{loaded = Loaded});
 	{BootPid,started,KernelPid} ->
 	    boot_loop(BootPid, new_kernelpid(KernelPid, BootPid, State));
 	{BootPid,progress,started} ->
@@ -338,12 +338,25 @@ boot_loop(BootPid, State) ->
     end.
 
 ensure_loaded(Module, Loaded) ->
+    case erlang:module_loaded(Module) of
+	true ->
+	    {{module, Module}, Loaded};
+	false ->
+	    do_ensure_loaded(Module, Loaded)
+    end.
+
+do_ensure_loaded(Module, Loaded) ->
     File = atom_to_list(Module) ++ objfile_extension(),
-    case catch load_mod(Module,File) of
-	{ok, FullName} ->
-	    {{module, Module}, [{Module, FullName}|Loaded]};
-	Res ->
-	    {Res, Loaded}
+    case erl_prim_loader:get_file(File) of
+	{ok,BinCode,FullName} ->
+	    case do_load_module(Module, BinCode) of
+		ok ->
+		    {{module, Module}, [{Module, FullName}|Loaded]};
+		error ->
+		    {error, [{Module, FullName}|Loaded]}
+	    end;
+	Error ->
+	    {Error, Loaded}
     end.
 
 %% Tell subscribed processes the system has started.
@@ -842,13 +855,6 @@ eval_script([{kernel_load_completed}|T], #es{load_mode=Mode}=Es0) ->
 	     _ -> Es0#es{prim_load=false}
 	 end,
     eval_script(T, Es);
-eval_script([{primLoad,[Mod]}|T], #es{prim_load=true}=Es) ->
-    %% Common special case (loading of error_handler). Nothing
-    %% to gain by parallel loading.
-    File = atom_to_list(Mod) ++ objfile_extension(),
-    {ok,Full} = load_mod(Mod, File),
-    init ! {self(),loaded,{Mod,Full}}, % Tell init about loaded module
-    eval_script(T, Es);
 eval_script([{primLoad,Mods}|T], #es{init=Init,prim_load=PrimLoad}=Es)
   when is_list(Mods) ->
     case PrimLoad of
@@ -873,14 +879,44 @@ eval_script([], #es{}) ->
 eval_script(What, #es{}) ->
     exit({'unexpected command in bootfile',What}).
 
-load_modules([Mod|Mods], Init) ->
-    File = atom_to_list(Mod) ++ objfile_extension(),
-    {ok,Full} = load_mod(Mod,File),
-    Init ! {self(),loaded,{Mod,Full}},	%Tell init about loaded module
-    load_modules(Mods, Init);
-load_modules([], _) ->
+load_modules(Mods0, Init) ->
+    Mods = [M || M <- Mods0, not erlang:module_loaded(M)],
+    F = prepare_loading_fun(),
+    case erl_prim_loader:get_modules(Mods, F) of
+	{ok,{Prep0,[]}} ->
+	    Prep = [Code || {_,{prepared,Code,_}} <- Prep0],
+	    ok = erlang:finish_loading(Prep),
+	    Loaded = [{Mod,Full} || {Mod,{_,_,Full}} <- Prep0],
+	    Init ! {self(),loaded,Loaded},
+	    Beams = [{M,Beam,Full} || {M,{on_load,Beam,Full}} <- Prep0],
+	    load_rest(Beams, Init);
+	{ok,{_,[_|_]=Errors}} ->
+	    Ms = [M || {M,_} <- Errors],
+	    exit({load_failed,Ms})
+    end.
+
+load_rest([{Mod,Beam,Full}|T], Init) ->
+    do_load_module(Mod, Beam),
+    Init ! {self(),loaded,[{Mod,Full}]},
+    load_rest(T, Init);
+load_rest([], _) ->
     ok.
 
+prepare_loading_fun() ->
+    fun(Mod, FullName, Beam) ->
+	    case erlang:prepare_loading(Mod, Beam) of
+		Prepared when is_binary(Prepared) ->
+		    case erlang:has_prepared_code_on_load(Prepared) of
+			true ->
+			    {ok,{on_load,Beam,FullName}};
+			false ->
+			    {ok,{prepared,Prepared,FullName}}
+		    end;
+		{error,_}=Error ->
+		    Error
+	    end
+    end.
+
 make_path(Pa, Pz, Path, Vars) ->
     append([Pa,append([fix_path(Path,Vars),Pz])]).
 
@@ -1033,35 +1069,17 @@ start_it([_|_]=MFA) ->
 	[M,F|Args] -> M:F(Args)	% Args is a list
     end.
 
-%%
-%% Fetch a module and load it into the system.
-%%
-load_mod(Mod, File) ->
-    case erlang:module_loaded(Mod) of
-	false ->
-	    case erl_prim_loader:get_file(File) of
-		{ok,BinCode,FullName} ->
-		    load_mod_code(Mod, BinCode, FullName);
-		_ ->
-		    exit({'cannot load',Mod,get_file})
-	    end;
-	_ -> % Already loaded.
-	    {ok,File}
-    end.
+%% Load a module.
 
-load_mod_code(Mod, BinCode, FullName) ->
-    case erlang:module_loaded(Mod) of
-	false ->
-	    case erlang:load_module(Mod, BinCode) of
-		{module,Mod} -> {ok,FullName};
-		{error,on_load} ->
-		    ?ON_LOAD_HANDLER ! {loaded,Mod},
-		    {ok,FullName};
-		Other ->
-		    exit({'cannot load',Mod,Other})
-	    end;
-	_ -> % Already loaded.
-	    {ok,FullName}
+do_load_module(Mod, BinCode) ->
+    case erlang:load_module(Mod, BinCode) of
+	{module,Mod} ->
+	    ok;
+	{error,on_load} ->
+	    ?ON_LOAD_HANDLER ! {loaded,Mod},
+	    ok;
+	_ ->
+	    error
     end.
 
 %% --------------------------------------------------------
diff --git a/lib/compiler/src/compile.erl b/lib/compiler/src/compile.erl
index 46917905de..332bc0bdf9 100644
--- a/lib/compiler/src/compile.erl
+++ b/lib/compiler/src/compile.erl
@@ -1681,6 +1681,7 @@ help(_) ->
 %%   Compile entry point for erl_compile.
 
 compile(File0, _OutFile, Options) ->
+    pre_load(),
     File = shorten_filename(File0),
     case file(File, make_erl_options(Options)) of
 	{ok,_Mod} -> ok;
@@ -1745,3 +1746,46 @@ make_erl_options(Opts) ->
 	end,
     Options ++ [report_errors, {cwd, Cwd}, {outdir, Outdir}|
 	        [{i, Dir} || Dir <- Includes]] ++ Specific.
+
+pre_load() ->
+    L = [beam_a,
+	 beam_asm,
+	 beam_block,
+	 beam_bool,
+	 beam_bs,
+	 beam_bsm,
+	 beam_clean,
+	 beam_dead,
+	 beam_dict,
+	 beam_except,
+	 beam_flatten,
+	 beam_jump,
+	 beam_opcodes,
+	 beam_peep,
+	 beam_receive,
+	 beam_reorder,
+	 beam_split,
+	 beam_trim,
+	 beam_type,
+	 beam_utils,
+	 beam_validator,
+	 beam_z,
+	 cerl,
+	 cerl_clauses,
+	 cerl_sets,
+	 cerl_trees,
+	 core_lib,
+	 epp,
+	 erl_bifs,
+	 erl_expand_records,
+	 erl_lint,
+	 erl_parse,
+	 erl_scan,
+	 sys_core_dsetel,
+	 sys_core_fold,
+	 sys_pre_expand,
+	 v3_codegen,
+	 v3_core,
+	 v3_kernel,
+	 v3_life],
+    code:ensure_modules_loaded(L).
diff --git a/lib/compiler/test/compile_SUITE.erl b/lib/compiler/test/compile_SUITE.erl
index b2e9558cba..fc04c9a60a 100644
--- a/lib/compiler/test/compile_SUITE.erl
+++ b/lib/compiler/test/compile_SUITE.erl
@@ -22,6 +22,7 @@
 %% Tests compile:file/1 and compile:file/2 with various options.
 
 -include_lib("common_test/include/ct.hrl").
+-include_lib("stdlib/include/erl_compile.hrl").
 
 -export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
 	 init_per_group/2,end_per_group/2,
@@ -32,7 +33,7 @@
 	 strict_record/1,
 	 missing_testheap/1, cover/1, env/1, core/1, asm/1,
 	 sys_pre_attributes/1, dialyzer/1,
-	 warnings/1
+	 warnings/1, pre_load_check/1
 	]).
 
 -export([init/3]).
@@ -50,7 +51,7 @@ all() ->
      other_output, encrypted_abstr,
      strict_record,
      missing_testheap, cover, env, core, asm,
-     sys_pre_attributes, dialyzer, warnings].
+     sys_pre_attributes, dialyzer, warnings, pre_load_check].
 
 groups() -> 
     [].
@@ -881,6 +882,115 @@ do_warnings_2([], Next, F) ->
     do_warnings_1(Next, F).
 
 
+%% Test that the compile:pre_load/0 function (used by 'erlc')
+%% pre-loads the modules that are used by a typical compilation.
+
+pre_load_check(Config) ->
+    case test_server:is_cover() of
+	true ->
+	    {skip,"Cover is running"};
+	false ->
+	    try
+		do_pre_load_check(Config)
+	    after
+		dbg:stop_clear()
+	    end
+    end.
+
+do_pre_load_check(Config) ->
+    DataDir = ?config(data_dir, Config),
+    Simple = filename:join(DataDir, "simple.erl"),
+    Big = filename:join(DataDir, "big.erl"),
+    {ok,_} = dbg:tracer(process, {fun pre_load_trace/2,[]}),
+    dbg:p(self(), call),
+    dbg:p(new, call),
+    {ok,_} = dbg:tpl({?MODULE,get_trace_data,0}, []),
+    {ok,_} = dbg:tp({code,ensure_modules_loaded,1}, []),
+
+    %% Compile a simple module using the erl_compile interface
+    %% to find out the modules that are pre-loaded by
+    %% compile:pre_load/0.
+    Opts = #options{specific=[binary]},
+    {ok,simple,_} = compile:compile(Simple, "", Opts),
+    [{code,ensure_modules_loaded,[PreLoaded0]}] = get_trace_data(),
+    PreLoaded1 = ordsets:from_list(PreLoaded0),
+
+    %% Since 'compile' is the function doing the pre-loaded,
+    %% it is useless to include it in the list.
+    case ordsets:is_element(compile, PreLoaded1) of
+	true ->
+	    io:put_chars("The 'compile' module should not be included "
+			 "in the list of modules to be pre-loaded."),
+	    ?t:fail(compile);
+	false ->
+	    []
+    end,
+    PreLoaded = ordsets:add_element(compile, PreLoaded1),
+
+    %% Now unload all pre-loaded modules and all modules in
+    %% compiler application. Then compile a module to find
+    %% which modules that get loaded.
+    CompilerMods = compiler_modules(),
+    Unload = ordsets:union(ordsets:from_list(CompilerMods), PreLoaded),
+    _ = [begin
+	     code:delete(M),
+	     code:purge(M)
+	 end || M <- Unload],
+
+    {ok,_} = dbg:ctp({code,ensure_modules_loaded,1}),
+    {ok,_} = dbg:tp({code,ensure_loaded,1}, []),
+    {ok,big,_} = compile:file(Big, [binary]),
+    WasLoaded0 = get_trace_data(),
+    WasLoaded1 = [M || {code,ensure_loaded,[M]} <- WasLoaded0],
+    WasLoaded = ordsets:from_list(WasLoaded1),
+
+    %% Check for modules that should have been pre-loaded.
+    case ordsets:subtract(WasLoaded, PreLoaded) of
+	[] ->
+	    ok;
+	[_|_]=NotPreLoaded ->
+	    io:format("The following modules were used "
+		      "but not pre-loaded:\n~p\n",
+		      [NotPreLoaded]),
+	    ?t:fail({not_preload,NotPreLoaded})
+    end,
+
+    %% Check for modules that should not be pre-loaded.
+    case ordsets:subtract(PreLoaded, WasLoaded) of
+	[] ->
+	    ok;
+	[_|_]=NotUsed ->
+	    io:format("The following modules were pre-loaded"
+		      " but not used:\n~p\n",
+		      [NotUsed]),
+	    ?t:fail({not_used,NotUsed})
+    end,
+
+    ok.
+
+get_trace_data() ->
+    %% Apparantely, doing a receive at the beginning of
+    %% a traced function can cause extra trace messages.
+    %% To avoid that, don't do the receive in this function.
+    do_get_trace_data().
+
+do_get_trace_data() ->
+    receive
+	{trace_data,Data} -> Data
+    end.
+
+pre_load_trace({trace,Pid,call,{?MODULE,get_trace_data,[]}}, Acc) ->
+    Pid ! {trace_data,Acc},
+    [];
+pre_load_trace({trace,_,call,MFA}, Acc) ->
+    [MFA|Acc].
+
+compiler_modules() ->
+    Wc = filename:join([code:lib_dir(compiler),"ebin","*.beam"]),
+    Ms = filelib:wildcard(Wc),
+    FN = filename,
+    [list_to_atom(FN:rootname(FN:basename(M), ".beam")) || M <- Ms].
+
 %%%
 %%% Utilities.
 %%%
diff --git a/lib/sasl/src/systools_make.erl b/lib/sasl/src/systools_make.erl
index d207dc15bb..154374cd8c 100644
--- a/lib/sasl/src/systools_make.erl
+++ b/lib/sasl/src/systools_make.erl
@@ -1453,16 +1453,37 @@ behave([H|T]) ->
 behave([]) ->
     [].
 
-%%______________________________________________________________________
-%% mandatory modules; this modules must be loaded before processes
-%% can be started. These are a collection of modules from the kernel
-%% and stdlib applications.
-%% Nowadays, error_handler dynamically loads almost every module.
-%% The error_handler self must still be there though.
-
 mandatory_modules() ->
-    %% Sorted
-    [error_handler].
+    [error_handler,				%Truly mandatory.
+
+     %% Modules that are almost always needed. Listing them here
+     %% helps the init module to load them faster. Modules not
+     %% listed here will be loaded by the error_handler module.
+     %%
+     %% Keep this list sorted.
+     application,
+     application_controller,
+     application_master,
+     code,
+     code_server,
+     erl_eval,
+     erl_lint,
+     erl_parse,
+     error_logger,
+     ets,
+     file,
+     filename,
+     file_server,
+     file_io_server,
+     gen,
+     gen_event,
+     gen_server,
+     heart,
+     kernel,
+     lists,
+     proc_lib,
+     supervisor
+    ].
 
 %%______________________________________________________________________
 %% This is the modules that are preloaded into the Erlang system.