From 68731828019e14ef46ef6f2b8bd2c6eb87589a43 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Sun, 22 Jan 2012 09:53:57 +0100
Subject: Fix on_load handling in modules loaded by code:load_binary/3

In "13.4 Running a function when a module is loaded" in the
Reference Manual, it is said that:

   A process that calls any function in a module whose on_load
   function has not yet returned will be suspended until the
   on_load function has returned.

That did not work if the module was loaded using code:load_binary/3.
Instead, the callers would get an 'undef' exception.
---
 lib/kernel/src/code_server.erl | 10 +++++++--
 lib/kernel/test/code_SUITE.erl | 49 +++++++++++++++++++++++++++++++++++++-----
 2 files changed, 52 insertions(+), 7 deletions(-)

(limited to 'lib/kernel')

diff --git a/lib/kernel/src/code_server.erl b/lib/kernel/src/code_server.erl
index 32a12e2b52..5d4f2eb70c 100644
--- a/lib/kernel/src/code_server.erl
+++ b/lib/kernel/src/code_server.erl
@@ -1317,15 +1317,21 @@ int_list([H|T]) when is_integer(H) -> int_list(T);
 int_list([_|_])                    -> false;
 int_list([])                       -> true.
 
+load_file(Mod0, {From,_}=Caller, St0) ->
+    Mod = to_atom(Mod0),
+    case pending_on_load(Mod, From, St0) of
+	no -> load_file_1(Mod, Caller, St0);
+	{yes,St} -> {noreply,St}
+    end.
 
-load_file(Mod, Caller, #state{path=Path,cache=no_cache}=St) ->
+load_file_1(Mod, Caller, #state{path=Path,cache=no_cache}=St) ->
     case mod_to_bin(Path, Mod) of
 	error ->
 	    {reply,{error,nofile},St};
 	{Mod,Binary,File} ->
 	    try_load_module(File, Mod, Binary, Caller, St)
     end;
-load_file(Mod, Caller, #state{cache=Cache}=St0) ->
+load_file_1(Mod, Caller, #state{cache=Cache}=St0) ->
     Key = {obj,Mod},
     case ets:lookup(Cache, Key) of
 	[] -> 
diff --git a/lib/kernel/test/code_SUITE.erl b/lib/kernel/test/code_SUITE.erl
index 10ab3e4370..99b0cd2ffb 100644
--- a/lib/kernel/test/code_SUITE.erl
+++ b/lib/kernel/test/code_SUITE.erl
@@ -30,9 +30,9 @@
 	 load_cached/1, start_node_with_cache/1, add_and_rehash/1,
 	 where_is_file_cached/1, where_is_file_no_cache/1,
 	 purge_stacktrace/1, mult_lib_roots/1, bad_erl_libs/1,
-	 code_archive/1, code_archive2/1, on_load/1,
-	 big_boot_embedded/1,
-	 on_load_embedded/1, on_load_errors/1, native_early_modules/1]).
+	 code_archive/1, code_archive2/1, on_load/1, on_load_binary/1,
+	 on_load_embedded/1, on_load_errors/1, big_boot_embedded/1,
+	 native_early_modules/1]).
 
 -export([init_per_testcase/2, end_per_testcase/2, 
 	 init_per_suite/1, end_per_suite/1,
@@ -55,8 +55,8 @@ all() ->
      add_and_rehash, where_is_file_no_cache,
      where_is_file_cached, purge_stacktrace, mult_lib_roots,
      bad_erl_libs, code_archive, code_archive2, on_load,
-     on_load_embedded, big_boot_embedded, on_load_errors, 
-     native_early_modules].
+     on_load_binary, on_load_embedded, on_load_errors,
+     big_boot_embedded, native_early_modules].
 
 groups() -> 
     [].
@@ -1286,6 +1286,45 @@ on_load_wait_for_all([Ref|T]) ->
     end;
 on_load_wait_for_all([]) -> ok.
 
+on_load_binary(_) ->
+    Master = on_load_binary_test_case_process,
+    register(Master, self()),
+
+    %% Construct, compile and pretty-print.
+    Mod = on_load_binary,
+    File = atom_to_list(Mod) ++ ".erl",
+    Forms = [{attribute,1,file,{File,1}},
+	     {attribute,1,module,Mod},
+	     {attribute,2,export,[{ok,0}]},
+	     {attribute,3,on_load,{init,0}},
+	     {function,5,init,0,
+	      [{clause,5,[],[],
+		[{op,6,'!',
+		  {atom,6,Master},
+		  {tuple,6,[{atom,6,Mod},{call,6,{atom,6,self},[]}]}},
+		 {'receive',7,[{clause,8,[{atom,8,go}],[],[{atom,8,ok}]}]}]}]},
+	     {function,11,ok,0,[{clause,11,[],[],[{atom,11,true}]}]}],
+    {ok,Mod,Bin} = compile:forms(Forms, [report]),
+    [io:put_chars(erl_pp:form(F)) || F <- Forms],
+
+    {Pid1,Ref1} = spawn_monitor(fun() ->
+					code:load_binary(Mod, File, Bin),
+					true = on_load_binary:ok()
+				end),
+    receive {Mod,OnLoadPid} -> ok end,
+    {Pid2,Ref2} = spawn_monitor(fun() ->
+					true = on_load_binary:ok()
+				end),
+    erlang:yield(),
+    OnLoadPid ! go,
+    receive {'DOWN',Ref1,process,Pid1,Exit1} -> ok end,
+    receive {'DOWN',Ref2,process,Pid2,Exit2} -> ok end,
+    normal = Exit1,
+    normal = Exit2,
+    true = code:delete(on_load_binary),
+    false = code:purge(on_load_binary),
+    ok.
+
 on_load_embedded(Config) when is_list(Config) ->
     try
 	on_load_embedded_1(Config)
-- 
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