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authorBjörn Gustavsson <[email protected]>2016-05-04 15:26:38 +0200
committerBjörn Gustavsson <[email protected]>2016-05-04 15:26:38 +0200
commitaf326dd9bc558eaf317a78f197f114d60290a536 (patch)
treeab773a37cb028cdc29712c212691300bff2586eb /lib/kernel/src
parentd9f30be07f6ebb014f6021ac2bd3a99894da4c53 (diff)
parent72fc3ab8b5bd19cbd7c9d0b507d97a942d4177de (diff)
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Merge branch 'bjorn/fix-on_load/OTP-12593'
* bjorn/fix-on_load/OTP-12593: Update documentation regarding improvements Correctly handle multiple load attempts when on_load is pending Avoid deadlock when an on_load function makes an external call to the module itself code_server: Eliminate unnecessary Tag in handle_call/3 Reimplement -on_load() Refactor erts_finish_loading() and insert_new_code() code_SUITE: Make on_load_binary/1 clearer by using merl
Diffstat (limited to 'lib/kernel/src')
-rw-r--r--lib/kernel/src/code_server.erl243
1 files changed, 139 insertions, 104 deletions
diff --git a/lib/kernel/src/code_server.erl b/lib/kernel/src/code_server.erl
index 90b2a06c46..6174136507 100644
--- a/lib/kernel/src/code_server.erl
+++ b/lib/kernel/src/code_server.erl
@@ -32,7 +32,12 @@
-import(lists, [foreach/2]).
--type on_load_item() :: {reference(),module(),file:name_all(),[pid()]}.
+-type on_load_action() ::
+ fun((term(), state()) -> {'reply',term(),state()} |
+ {'noreply',state()}).
+
+-type on_load_item() :: {{pid(),reference()},module(),
+ [{pid(),on_load_action()}]}.
-record(state, {supervisor :: pid(),
root :: file:name_all(),
@@ -142,7 +147,7 @@ reply(Pid, Res) ->
loop(#state{supervisor=Supervisor}=State0) ->
receive
{code_call, Pid, Req} ->
- case handle_call(Req, {Pid, call}, State0) of
+ case handle_call(Req, Pid, State0) of
{reply, Res, State} ->
_ = reply(Pid, Res),
loop(State);
@@ -155,8 +160,8 @@ loop(#state{supervisor=Supervisor}=State0) ->
system_terminate(Reason, Supervisor, [], State0);
{system, From, Msg} ->
handle_system_msg(running,Msg, From, Supervisor, State0);
- {'DOWN',Ref,process,_,Res} ->
- State = finish_on_load(Ref, Res, State0),
+ {'DOWN',Ref,process,Pid,Res} ->
+ State = finish_on_load({Pid,Ref}, Res, State0),
loop(State);
_Msg ->
loop(State0)
@@ -225,90 +230,90 @@ system_code_change(State, _Module, _OldVsn, _Extra) ->
%% The gen_server call back functions.
%%
-handle_call({stick_dir,Dir}, {_From,_Tag}, S) ->
+handle_call({stick_dir,Dir}, _From, S) ->
{reply,stick_dir(Dir, true, S),S};
-handle_call({unstick_dir,Dir}, {_From,_Tag}, S) ->
+handle_call({unstick_dir,Dir}, _From, S) ->
{reply,stick_dir(Dir, false, S),S};
-handle_call({stick_mod,Mod}, {_From,_Tag}, S) ->
+handle_call({stick_mod,Mod}, _From, S) ->
{reply,stick_mod(Mod, true, S),S};
-handle_call({unstick_mod,Mod}, {_From,_Tag}, S) ->
+handle_call({unstick_mod,Mod}, _From, S) ->
{reply,stick_mod(Mod, false, S),S};
-handle_call({dir,Dir}, {_From,_Tag}, S) ->
+handle_call({dir,Dir}, _From, S) ->
Root = S#state.root,
Resp = do_dir(Root,Dir,S#state.namedb),
{reply,Resp,S};
-handle_call({load_file,Mod}, Caller, St) when is_atom(Mod) ->
- load_file(Mod, Caller, St);
+handle_call({load_file,Mod}, From, St) when is_atom(Mod) ->
+ load_file(Mod, From, St);
-handle_call({add_path,Where,Dir0}, {_From,_Tag},
+handle_call({add_path,Where,Dir0}, _From,
#state{namedb=Namedb,path=Path0}=S) ->
{Resp,Path} = add_path(Where, Dir0, Path0, Namedb),
{reply,Resp,S#state{path=Path}};
-handle_call({add_paths,Where,Dirs0}, {_From,_Tag},
+handle_call({add_paths,Where,Dirs0}, _From,
#state{namedb=Namedb,path=Path0}=S) ->
{Resp,Path} = add_paths(Where, Dirs0, Path0, Namedb),
{reply,Resp,S#state{path=Path}};
-handle_call({set_path,PathList}, {_From,_Tag},
+handle_call({set_path,PathList}, _From,
#state{path=Path0,namedb=Namedb}=S) ->
{Resp,Path,NewDb} = set_path(PathList, Path0, Namedb),
{reply,Resp,S#state{path=Path,namedb=NewDb}};
-handle_call({del_path,Name}, {_From,_Tag},
+handle_call({del_path,Name}, _From,
#state{path=Path0,namedb=Namedb}=S) ->
{Resp,Path} = del_path(Name, Path0, Namedb),
{reply,Resp,S#state{path=Path}};
-handle_call({replace_path,Name,Dir}, {_From,_Tag},
+handle_call({replace_path,Name,Dir}, _From,
#state{path=Path0,namedb=Namedb}=S) ->
{Resp,Path} = replace_path(Name, Dir, Path0, Namedb),
{reply,Resp,S#state{path=Path}};
-handle_call(get_path, {_From,_Tag}, S) ->
+handle_call(get_path, _From, S) ->
{reply,S#state.path,S};
%% Messages to load, delete and purge modules/files.
-handle_call({load_abs,File,Mod}, Caller, S) when is_atom(Mod) ->
+handle_call({load_abs,File,Mod}, From, S) when is_atom(Mod) ->
case modp(File) of
false ->
{reply,{error,badarg},S};
true ->
- load_abs(File, Mod, Caller, S)
+ load_abs(File, Mod, From, S)
end;
-handle_call({load_binary,Mod,File,Bin}, Caller, S) when is_atom(Mod) ->
- do_load_binary(Mod, File, Bin, Caller, S);
+handle_call({load_binary,Mod,File,Bin}, From, S) when is_atom(Mod) ->
+ do_load_binary(Mod, File, Bin, From, S);
-handle_call({load_native_partial,Mod,Bin}, {_From,_Tag}, S) ->
+handle_call({load_native_partial,Mod,Bin}, _From, S) ->
Architecture = erlang:system_info(hipe_architecture),
Result = (catch hipe_unified_loader:load(Mod, Bin, Architecture)),
Status = hipe_result_to_status(Result, S),
{reply,Status,S};
-handle_call({load_native_sticky,Mod,Bin,WholeModule}, {_From,_Tag}, S) ->
+handle_call({load_native_sticky,Mod,Bin,WholeModule}, _From, S) ->
Architecture = erlang:system_info(hipe_architecture),
Result = (catch hipe_unified_loader:load_module(Mod, Bin, WholeModule,
Architecture)),
Status = hipe_result_to_status(Result, S),
{reply,Status,S};
-handle_call({ensure_loaded,Mod}, Caller, St) when is_atom(Mod) ->
+handle_call({ensure_loaded,Mod}, From, St) when is_atom(Mod) ->
case erlang:module_loaded(Mod) of
true ->
{reply,{module,Mod},St};
false when St#state.mode =:= interactive ->
- load_file(Mod, Caller, St);
+ ensure_loaded(Mod, From, St);
false ->
{reply,{error,embedded},St}
end;
-handle_call({delete,Mod}, {_From,_Tag}, St) when is_atom(Mod) ->
+handle_call({delete,Mod}, _From, St) when is_atom(Mod) ->
case catch erlang:delete_module(Mod) of
true ->
ets:delete(St#state.moddb, Mod),
@@ -317,48 +322,50 @@ handle_call({delete,Mod}, {_From,_Tag}, St) when is_atom(Mod) ->
{reply,false,St}
end;
-handle_call({purge,Mod}, {_From,_Tag}, St) when is_atom(Mod) ->
+handle_call({purge,Mod}, _From, St) when is_atom(Mod) ->
{reply,do_purge(Mod),St};
-handle_call({soft_purge,Mod}, {_From,_Tag}, St) when is_atom(Mod) ->
+handle_call({soft_purge,Mod}, _From, St) when is_atom(Mod) ->
{reply,do_soft_purge(Mod),St};
-handle_call({is_loaded,Mod}, {_From,_Tag}, St) when is_atom(Mod) ->
+handle_call({is_loaded,Mod}, _From, St) when is_atom(Mod) ->
{reply,is_loaded(Mod, St#state.moddb),St};
-handle_call(all_loaded, {_From,_Tag}, S) ->
+handle_call(all_loaded, _From, S) ->
Db = S#state.moddb,
{reply,all_loaded(Db),S};
-handle_call({get_object_code,Mod}, {_From,_Tag}, St) when is_atom(Mod) ->
+handle_call({get_object_code,Mod}, _From, St) when is_atom(Mod) ->
Path = St#state.path,
case mod_to_bin(Path, Mod) of
{_,Bin,FName} -> {reply,{Mod,Bin,FName},St};
Error -> {reply,Error,St}
end;
-handle_call({is_sticky, Mod}, {_From,_Tag}, S) ->
+handle_call({is_sticky, Mod}, _From, S) ->
Db = S#state.moddb,
{reply, is_sticky(Mod,Db), S};
-handle_call(stop,{_From,_Tag}, S) ->
+handle_call(stop,_From, S) ->
{stop,normal,stopped,S};
-handle_call({set_primary_archive, File, ArchiveBin, FileInfo, ParserFun}, {_From,_Tag}, S=#state{mode=Mode}) ->
- case erl_prim_loader:set_primary_archive(File, ArchiveBin, FileInfo, ParserFun) of
+handle_call({set_primary_archive, File, ArchiveBin, FileInfo, ParserFun},
+ _From, S=#state{mode=Mode}) ->
+ case erl_prim_loader:set_primary_archive(File, ArchiveBin, FileInfo,
+ ParserFun) of
{ok, Files} ->
{reply, {ok, Mode, Files}, S};
{error, _Reason} = Error ->
{reply, Error, S}
end;
-handle_call(get_mode, {_From,_Tag}, S=#state{mode=Mode}) ->
+handle_call(get_mode, _From, S=#state{mode=Mode}) ->
{reply, Mode, S};
-handle_call({finish_loading,Prepared,EnsureLoaded}, {_,_}, S) ->
+handle_call({finish_loading,Prepared,EnsureLoaded}, _From, S) ->
{reply,finish_loading(Prepared, EnsureLoaded, S),S};
-handle_call(Other,{_From,_Tag}, S) ->
+handle_call(Other,_From, S) ->
error_msg(" ** Codeserver*** ignoring ~w~n ",[Other]),
{noreply,S}.
@@ -1054,14 +1061,14 @@ add_paths(Where,[Dir|Tail],Path,NameDb) ->
add_paths(_,_,Path,_) ->
{ok,Path}.
-do_load_binary(Module, File, Binary, Caller, St) ->
+do_load_binary(Module, File, Binary, From, St) ->
case modp(File) andalso is_binary(Binary) of
true ->
case erlang:module_loaded(Module) of
true -> do_purge(Module);
false -> ok
end,
- try_load_module(File, Module, Binary, Caller, St);
+ try_load_module(File, Module, Binary, From, St);
false ->
{reply,{error,badarg},St}
end.
@@ -1070,63 +1077,61 @@ modp(Atom) when is_atom(Atom) -> true;
modp(List) when is_list(List) -> int_list(List);
modp(_) -> false.
-load_abs(File, Mod, Caller, St) ->
+load_abs(File, Mod, From, St) ->
Ext = objfile_extension(),
FileName0 = lists:concat([File, Ext]),
FileName = absname(FileName0),
case erl_prim_loader:get_file(FileName) of
{ok,Bin,_} ->
- try_load_module(FileName, Mod, Bin, Caller, St);
+ try_load_module(FileName, Mod, Bin, From, St);
error ->
{reply,{error,nofile},St}
end.
-try_load_module(File, Mod, Bin, {From,_}=Caller, St0) ->
- case pending_on_load(Mod, From, St0) of
- no ->
- try_load_module_1(File, Mod, Bin, Caller, St0);
- {yes,St} ->
- {noreply,St}
- end.
+try_load_module(File, Mod, Bin, From, St) ->
+ Action = fun(_, S) ->
+ try_load_module_1(File, Mod, Bin, From, S)
+ end,
+ handle_pending_on_load(Action, Mod, From, St).
-try_load_module_1(File, Mod, Bin, Caller, #state{moddb=Db}=St) ->
+try_load_module_1(File, Mod, Bin, From, #state{moddb=Db}=St) ->
case is_sticky(Mod, Db) of
true -> %% Sticky file reject the load
error_msg("Can't load module '~w' that resides in sticky dir\n",[Mod]),
{reply,{error,sticky_directory},St};
false ->
Architecture = erlang:system_info(hipe_architecture),
- try_load_module_2(File, Mod, Bin, Caller, Architecture, St)
+ try_load_module_2(File, Mod, Bin, From, Architecture, St)
end.
-try_load_module_2(File, Mod, Bin, Caller, undefined, St) ->
- try_load_module_3(File, Mod, Bin, Caller, undefined, St);
-try_load_module_2(File, Mod, Bin, Caller, Architecture,
+try_load_module_2(File, Mod, Bin, From, undefined, St) ->
+ try_load_module_3(File, Mod, Bin, From, undefined, St);
+try_load_module_2(File, Mod, Bin, From, Architecture,
#state{moddb=Db}=St) ->
case catch hipe_unified_loader:load_native_code(Mod, Bin, Architecture) of
{module,Mod} = Module ->
ets:insert(Db, [{{native,Mod},true},{Mod,File}]),
{reply,Module,St};
no_native ->
- try_load_module_3(File, Mod, Bin, Caller, Architecture, St);
+ try_load_module_3(File, Mod, Bin, From, Architecture, St);
Error ->
error_msg("Native loading of ~ts failed: ~p\n", [File,Error]),
{reply,ok,St}
end.
-try_load_module_3(File, Mod, Bin, Caller, Architecture,
- #state{moddb=Db}=St) ->
- case erlang:load_module(Mod, Bin) of
- {module,Mod} = Module ->
- ets:insert(Db, {Mod,File}),
- post_beam_load([Mod], Architecture, St),
- {reply,Module,St};
- {error,on_load} ->
- handle_on_load(Mod, File, Caller, St);
- {error,What} = Error ->
- error_msg("Loading of ~ts failed: ~p\n", [File, What]),
- {reply,Error,St}
- end.
+try_load_module_3(File, Mod, Bin, From, Architecture, St0) ->
+ Action = fun({module,_}=Module, #state{moddb=Db}=S) ->
+ ets:insert(Db, {Mod,File}),
+ post_beam_load([Mod], Architecture, S),
+ {reply,Module,S};
+ ({error,on_load_failure}=Error, S) ->
+ {reply,Error,S};
+ ({error,What}=Error, S) ->
+ error_msg("Loading of ~ts failed: ~p\n", [File, What]),
+ {reply,Error,S}
+ end,
+ Res = erlang:load_module(Mod, Bin),
+ handle_on_load(Res, Action, Mod, From, St0).
hipe_result_to_status(Result, #state{moddb=Db}) ->
case Result of
@@ -1151,18 +1156,29 @@ int_list([H|T]) when is_integer(H) -> int_list(T);
int_list([_|_]) -> false;
int_list([]) -> true.
-load_file(Mod, {From,_}=Caller, St0) ->
- case pending_on_load(Mod, From, St0) of
- no -> load_file_1(Mod, Caller, St0);
- {yes,St} -> {noreply,St}
- end.
-
-load_file_1(Mod, Caller, #state{path=Path}=St) ->
+ensure_loaded(Mod, From, St0) ->
+ Action = fun(_, S) ->
+ case erlang:module_loaded(Mod) of
+ true ->
+ {reply,{module,Mod},S};
+ false ->
+ load_file_1(Mod, From, S)
+ end
+ end,
+ handle_pending_on_load(Action, Mod, From, St0).
+
+load_file(Mod, From, St0) ->
+ Action = fun(_, S) ->
+ load_file_1(Mod, From, S)
+ end,
+ handle_pending_on_load(Action, Mod, From, St0).
+
+load_file_1(Mod, From, #state{path=Path}=St) ->
case mod_to_bin(Path, Mod) of
error ->
{reply,{error,nofile},St};
{Mod,Binary,File} ->
- try_load_module_1(File, Mod, Binary, Caller, St)
+ try_load_module_1(File, Mod, Binary, From, St)
end.
mod_to_bin([Dir|Tail], Mod) ->
@@ -1305,59 +1321,78 @@ run([F|Fs], Data0) ->
%% The on_load functionality.
%% -------------------------------------------------------
-handle_on_load(Mod, File, {From,_}, #state{on_load=OnLoad0}=St0) ->
+handle_on_load({error,on_load}, Action, Mod, From, St0) ->
+ #state{on_load=OnLoad0} = St0,
Fun = fun() ->
Res = erlang:call_on_load_function(Mod),
exit(Res)
end,
- {_,Ref} = spawn_monitor(Fun),
- OnLoad = [{Ref,Mod,File,[From]}|OnLoad0],
+ PidRef = spawn_monitor(Fun),
+ PidAction = {From,Action},
+ OnLoad = [{PidRef,Mod,[PidAction]}|OnLoad0],
St = St0#state{on_load=OnLoad},
- {noreply,St}.
+ {noreply,St};
+handle_on_load(Res, Action, _, _, St) ->
+ Action(Res, St).
-pending_on_load(_, _, #state{on_load=[]}) ->
- no;
-pending_on_load(Mod, From, #state{on_load=OnLoad0}=St) ->
- case lists:keymember(Mod, 2, OnLoad0) of
+handle_pending_on_load(Action, Mod, From, #state{on_load=OnLoad0}=St) ->
+ case lists:keyfind(Mod, 2, OnLoad0) of
false ->
- no;
- true ->
- OnLoad = pending_on_load_1(Mod, From, OnLoad0),
- {yes,St#state{on_load=OnLoad}}
+ Action(ok, St);
+ {{From,_Ref},Mod,_Pids} ->
+ %% The on_load function tried to make an external
+ %% call to its own module. That would be a deadlock.
+ %% Fail the call. (The call is probably from error_handler,
+ %% and it will ignore the actual error reason and cause
+ %% an undef execption.)
+ {reply,{error,deadlock},St};
+ {_,_,_} ->
+ OnLoad = handle_pending_on_load_1(Mod, {From,Action}, OnLoad0),
+ {noreply,St#state{on_load=OnLoad}}
end.
-pending_on_load_1(Mod, From, [{Ref,Mod,File,Pids}|T]) ->
- [{Ref,Mod,File,[From|Pids]}|T];
-pending_on_load_1(Mod, From, [H|T]) ->
- [H|pending_on_load_1(Mod, From, T)];
-pending_on_load_1(_, _, []) -> [].
+handle_pending_on_load_1(Mod, From, [{PidRef,Mod,Pids}|T]) ->
+ [{PidRef,Mod,[From|Pids]}|T];
+handle_pending_on_load_1(Mod, From, [H|T]) ->
+ [H|handle_pending_on_load_1(Mod, From, T)];
+handle_pending_on_load_1(_, _, []) -> [].
-finish_on_load(Ref, OnLoadRes, #state{on_load=OnLoad0,moddb=Db}=State) ->
- case lists:keyfind(Ref, 1, OnLoad0) of
+finish_on_load(PidRef, OnLoadRes, #state{on_load=OnLoad0}=St0) ->
+ case lists:keyfind(PidRef, 1, OnLoad0) of
false ->
%% Since this process in general silently ignores messages
%% it doesn't understand, it should also ignore a 'DOWN'
%% message with an unknown reference.
- State;
- {Ref,Mod,File,WaitingPids} ->
- finish_on_load_1(Mod, File, OnLoadRes, WaitingPids, Db),
- OnLoad = [E || {R,_,_,_}=E <- OnLoad0, R =/= Ref],
- State#state{on_load=OnLoad}
+ St0;
+ {PidRef,Mod,Waiting} ->
+ St = finish_on_load_1(Mod, OnLoadRes, Waiting, St0),
+ OnLoad = [E || {R,_,_}=E <- OnLoad0, R =/= PidRef],
+ St#state{on_load=OnLoad}
end.
-finish_on_load_1(Mod, File, OnLoadRes, WaitingPids, Db) ->
+finish_on_load_1(Mod, OnLoadRes, Waiting, St) ->
Keep = OnLoadRes =:= ok,
erlang:finish_after_on_load(Mod, Keep),
Res = case Keep of
false ->
_ = finish_on_load_report(Mod, OnLoadRes),
+ _ = erts_code_purger:purge(Mod),
{error,on_load_failure};
true ->
- ets:insert(Db, {Mod,File}),
{module,Mod}
end,
- _ = [reply(Pid, Res) || Pid <- WaitingPids],
- ok.
+ finish_on_load_2(Waiting, Res, St).
+
+finish_on_load_2([{Pid,Action}|T], Res, St0) ->
+ case Action(Res, St0) of
+ {reply,Rep,St} ->
+ _ = reply(Pid, Rep),
+ finish_on_load_2(T, Res, St);
+ {noreply,St} ->
+ finish_on_load_2(T, Res, St)
+ end;
+finish_on_load_2([], _, St) ->
+ St.
finish_on_load_report(_Mod, Atom) when is_atom(Atom) ->
%% No error reports for atoms.