%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2012. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(proc_lib).
%% This module is used to set some initial information
%% in each created process.
%% Then a process terminates the Reason is checked and
%% a crash report is generated if the Reason was not expected.
-export([spawn/1, spawn_link/1, spawn/2, spawn_link/2,
spawn/3, spawn_link/3, spawn/4, spawn_link/4,
spawn_opt/2, spawn_opt/3, spawn_opt/4, spawn_opt/5,
start/3, start/4, start/5, start_link/3, start_link/4, start_link/5,
hibernate/3,
init_ack/1, init_ack/2,
init_p/3,init_p/5,format/1,initial_call/1,translate_initial_call/1]).
%% Internal exports.
-export([wake_up/3]).
-export_type([spawn_option/0]).
%%-----------------------------------------------------------------------------
-type priority_level() :: 'high' | 'low' | 'max' | 'normal'.
-type spawn_option() :: 'link'
| 'monitor'
| {'priority', priority_level()}
| {'min_heap_size', non_neg_integer()}
| {'min_bin_vheap_size', non_neg_integer()}
| {'fullsweep_after', non_neg_integer()}.
-type dict_or_pid() :: pid()
| (ProcInfo :: [_])
| {X :: integer(), Y :: integer(), Z :: integer()}.
%%-----------------------------------------------------------------------------
-spec spawn(Fun) -> pid() when
Fun :: function().
spawn(F) when is_function(F) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
erlang:spawn(?MODULE, init_p, [Parent,Ancestors,F]).
-spec spawn(Module, Function, Args) -> pid() when
Module :: module(),
Function :: atom(),
Args :: [term()].
spawn(M,F,A) when is_atom(M), is_atom(F), is_list(A) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
erlang:spawn(?MODULE, init_p, [Parent,Ancestors,M,F,A]).
-spec spawn_link(Fun) -> pid() when
Fun :: function().
spawn_link(F) when is_function(F) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
erlang:spawn_link(?MODULE, init_p, [Parent,Ancestors,F]).
-spec spawn_link(Module, Function, Args) -> pid() when
Module :: module(),
Function :: atom(),
Args :: [term()].
spawn_link(M,F,A) when is_atom(M), is_atom(F), is_list(A) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
erlang:spawn_link(?MODULE, init_p, [Parent,Ancestors,M,F,A]).
-spec spawn(Node, Fun) -> pid() when
Node :: node(),
Fun :: function().
spawn(Node, F) when is_function(F) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
erlang:spawn(Node, ?MODULE, init_p, [Parent,Ancestors,F]).
-spec spawn(Node, Module, Function, Args) -> pid() when
Node :: node(),
Module :: module(),
Function :: atom(),
Args :: [term()].
spawn(Node, M, F, A) when is_atom(M), is_atom(F), is_list(A) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
erlang:spawn(Node, ?MODULE, init_p, [Parent,Ancestors,M,F,A]).
-spec spawn_link(Node, Fun) -> pid() when
Node :: node(),
Fun :: function().
spawn_link(Node, F) when is_function(F) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
erlang:spawn_link(Node, ?MODULE, init_p, [Parent,Ancestors,F]).
-spec spawn_link(Node, Module, Function, Args) -> pid() when
Node :: node(),
Module :: module(),
Function :: atom(),
Args :: [term()].
spawn_link(Node, M, F, A) when is_atom(M), is_atom(F), is_list(A) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
erlang:spawn_link(Node, ?MODULE, init_p, [Parent,Ancestors,M,F,A]).
-spec spawn_opt(Fun, SpawnOpts) -> pid() when
Fun :: function(),
SpawnOpts :: [spawn_option()].
spawn_opt(F, Opts) when is_function(F) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
check_for_monitor(Opts),
erlang:spawn_opt(?MODULE, init_p, [Parent,Ancestors,F],Opts).
-spec spawn_opt(Node, Function, SpawnOpts) -> pid() when
Node :: node(),
Function :: function(),
SpawnOpts :: [spawn_option()].
spawn_opt(Node, F, Opts) when is_function(F) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
check_for_monitor(Opts),
erlang:spawn_opt(Node, ?MODULE, init_p, [Parent,Ancestors,F], Opts).
-spec spawn_opt(Module, Function, Args, SpawnOpts) -> pid() when
Module :: module(),
Function :: atom(),
Args :: [term()],
SpawnOpts :: [spawn_option()].
spawn_opt(M, F, A, Opts) when is_atom(M), is_atom(F), is_list(A) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
check_for_monitor(Opts),
erlang:spawn_opt(?MODULE, init_p, [Parent,Ancestors,M,F,A], Opts).
-spec spawn_opt(Node, Module, Function, Args, SpawnOpts) -> pid() when
Node :: node(),
Module :: module(),
Function :: atom(),
Args :: [term()],
SpawnOpts :: [spawn_option()].
spawn_opt(Node, M, F, A, Opts) when is_atom(M), is_atom(F), is_list(A) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
check_for_monitor(Opts),
erlang:spawn_opt(Node, ?MODULE, init_p, [Parent,Ancestors,M,F,A], Opts).
%% OTP-6345
%% monitor spawn_opt option is currently not possible to use
check_for_monitor(SpawnOpts) ->
case lists:member(monitor, SpawnOpts) of
true ->
erlang:error(badarg);
false ->
false
end.
spawn_mon(M,F,A) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
erlang:spawn_monitor(?MODULE, init_p, [Parent,Ancestors,M,F,A]).
spawn_opt_mon(M, F, A, Opts) when is_atom(M), is_atom(F), is_list(A) ->
Parent = get_my_name(),
Ancestors = get_ancestors(),
check_for_monitor(Opts),
erlang:spawn_opt(?MODULE, init_p, [Parent,Ancestors,M,F,A], [monitor|Opts]).
-spec hibernate(Module, Function, Args) -> no_return() when
Module :: module(),
Function :: atom(),
Args :: [term()].
hibernate(M, F, A) when is_atom(M), is_atom(F), is_list(A) ->
erlang:hibernate(?MODULE, wake_up, [M, F, A]).
ensure_link(SpawnOpts) ->
case lists:member(link, SpawnOpts) of
true ->
SpawnOpts;
false ->
[link|SpawnOpts]
end.
-spec init_p(pid(), [pid()], function()) -> term().
init_p(Parent, Ancestors, Fun) when is_function(Fun) ->
put('$ancestors', [Parent|Ancestors]),
{module,Mod} = erlang:fun_info(Fun, module),
{name,Name} = erlang:fun_info(Fun, name),
{arity,Arity} = erlang:fun_info(Fun, arity),
put('$initial_call', {Mod,Name,Arity}),
try
Fun()
catch
Class:Reason ->
exit_p(Class, Reason)
end.
-spec init_p(pid(), [pid()], atom(), atom(), [term()]) -> term().
init_p(Parent, Ancestors, M, F, A) when is_atom(M), is_atom(F), is_list(A) ->
put('$ancestors', [Parent|Ancestors]),
put('$initial_call', trans_init(M, F, A)),
init_p_do_apply(M, F, A).
init_p_do_apply(M, F, A) ->
try
apply(M, F, A)
catch
Class:Reason ->
exit_p(Class, Reason)
end.
-spec wake_up(atom(), atom(), [term()]) -> term().
wake_up(M, F, A) when is_atom(M), is_atom(F), is_list(A) ->
try
apply(M, F, A)
catch
Class:Reason ->
exit_p(Class, Reason)
end.
exit_p(Class, Reason) ->
case get('$initial_call') of
{M,F,A} when is_atom(M), is_atom(F), is_integer(A) ->
MFA = {M,F,make_dummy_args(A, [])},
crash_report(Class, Reason, MFA),
exit(Reason);
_ ->
%% The process dictionary has been cleared or
%% possibly modified.
crash_report(Class, Reason, []),
exit(Reason)
end.
-spec start(Module, Function, Args) -> Ret when
Module :: module(),
Function :: atom(),
Args :: [term()],
Ret :: term() | {error, Reason :: term()}.
start(M, F, A) when is_atom(M), is_atom(F), is_list(A) ->
start(M, F, A, infinity).
-spec start(Module, Function, Args, Time) -> Ret when
Module :: module(),
Function :: atom(),
Args :: [term()],
Time :: timeout(),
Ret :: term() | {error, Reason :: term()}.
start(M, F, A, Timeout) when is_atom(M), is_atom(F), is_list(A) ->
PidRef = spawn_mon(M, F, A),
sync_wait_mon(PidRef, Timeout).
-spec start(Module, Function, Args, Time, SpawnOpts) -> Ret when
Module :: module(),
Function :: atom(),
Args :: [term()],
Time :: timeout(),
SpawnOpts :: [spawn_option()],
Ret :: term() | {error, Reason :: term()}.
start(M, F, A, Timeout, SpawnOpts) when is_atom(M), is_atom(F), is_list(A) ->
PidRef = spawn_opt_mon(M, F, A, SpawnOpts),
sync_wait_mon(PidRef, Timeout).
-spec start_link(Module, Function, Args) -> Ret when
Module :: module(),
Function :: atom(),
Args :: [term()],
Ret :: term() | {error, Reason :: term()}.
start_link(M, F, A) when is_atom(M), is_atom(F), is_list(A) ->
start_link(M, F, A, infinity).
-spec start_link(Module, Function, Args, Time) -> Ret when
Module :: module(),
Function :: atom(),
Args :: [term()],
Time :: timeout(),
Ret :: term() | {error, Reason :: term()}.
start_link(M, F, A, Timeout) when is_atom(M), is_atom(F), is_list(A) ->
Pid = ?MODULE:spawn_link(M, F, A),
sync_wait(Pid, Timeout).
-spec start_link(Module, Function, Args, Time, SpawnOpts) -> Ret when
Module :: module(),
Function :: atom(),
Args :: [term()],
Time :: timeout(),
SpawnOpts :: [spawn_option()],
Ret :: term() | {error, Reason :: term()}.
start_link(M,F,A,Timeout,SpawnOpts) when is_atom(M), is_atom(F), is_list(A) ->
Pid = ?MODULE:spawn_opt(M, F, A, ensure_link(SpawnOpts)),
sync_wait(Pid, Timeout).
sync_wait(Pid, Timeout) ->
receive
{ack, Pid, Return} ->
Return;
{'EXIT', Pid, Reason} ->
{error, Reason}
after Timeout ->
unlink(Pid),
exit(Pid, kill),
flush(Pid),
{error, timeout}
end.
sync_wait_mon({Pid, Ref}, Timeout) ->
receive
{ack, Pid, Return} ->
erlang:demonitor(Ref, [flush]),
Return;
{'DOWN', Ref, _Type, Pid, Reason} ->
{error, Reason};
{'EXIT', Pid, Reason} -> %% link as spawn_opt?
erlang:demonitor(Ref, [flush]),
{error, Reason}
after Timeout ->
erlang:demonitor(Ref, [flush]),
exit(Pid, kill),
flush(Pid),
{error, timeout}
end.
-spec flush(pid()) -> 'true'.
flush(Pid) ->
receive
{'EXIT', Pid, _} ->
true
after 0 ->
true
end.
-spec init_ack(Parent, Ret) -> 'ok' when
Parent :: pid(),
Ret :: term().
init_ack(Parent, Return) ->
Parent ! {ack, self(), Return},
ok.
-spec init_ack(Ret) -> 'ok' when
Ret :: term().
init_ack(Return) ->
[Parent|_] = get('$ancestors'),
init_ack(Parent, Return).
%% -----------------------------------------------------
%% Fetch the initial call of a proc_lib spawned process.
%% -----------------------------------------------------
-spec initial_call(Process) -> {Module, Function, Args} | 'false' when
Process :: dict_or_pid(),
Module :: module(),
Function :: atom(),
Args :: [atom()].
initial_call(DictOrPid) ->
case raw_initial_call(DictOrPid) of
{M,F,A} ->
{M,F,make_dummy_args(A, [])};
false ->
false
end.
make_dummy_args(0, Acc) ->
Acc;
make_dummy_args(N, Acc) ->
Arg = list_to_atom("Argument__" ++ integer_to_list(N)),
make_dummy_args(N-1, [Arg|Acc]).
%% -----------------------------------------------------
%% Translate the '$initial_call' to some useful information.
%% However, the arguments are not returned here; only the
%% arity of the initial function.
%% This function is typically called from c:i() and c:regs().
%% -----------------------------------------------------
-spec translate_initial_call(Process) -> {Module, Function, Arity} when
Process :: dict_or_pid(),
Module :: module(),
Function :: atom(),
Arity :: byte().
translate_initial_call(DictOrPid) ->
case raw_initial_call(DictOrPid) of
{_,_,_}=MFA ->
MFA;
false ->
{?MODULE,init_p,5}
end.
%% -----------------------------------------------------
%% Fetch the initial call information exactly as stored
%% in the process dictionary.
%% -----------------------------------------------------
raw_initial_call({X,Y,Z}) when is_integer(X), is_integer(Y), is_integer(Z) ->
raw_initial_call(c:pid(X,Y,Z));
raw_initial_call(Pid) when is_pid(Pid) ->
case get_process_info(Pid, dictionary) of
{dictionary,Dict} ->
raw_init_call(Dict);
_ ->
false
end;
raw_initial_call(ProcInfo) when is_list(ProcInfo) ->
case lists:keyfind(dictionary, 1, ProcInfo) of
{dictionary,Dict} ->
raw_init_call(Dict);
_ ->
false
end.
raw_init_call(Dict) ->
case lists:keyfind('$initial_call', 1, Dict) of
{_,{_,_,_}=MFA} ->
MFA;
_ ->
false
end.
%% -----------------------------------------------------
%% Translate the initial call to some useful information.
%% -----------------------------------------------------
trans_init(gen,init_it,[gen_server,_,_,supervisor,{_,Module,_},_]) ->
{supervisor,Module,1};
trans_init(gen,init_it,[gen_server,_,_,_,supervisor,{_,Module,_},_]) ->
{supervisor,Module,1};
trans_init(gen,init_it,[gen_server,_,_,supervisor_bridge,[Module|_],_]) ->
{supervisor_bridge,Module,1};
trans_init(gen,init_it,[gen_server,_,_,_,supervisor_bridge,[Module|_],_]) ->
{supervisor_bridge,Module,1};
trans_init(gen,init_it,[gen_server,_,_,Module,_,_]) ->
{Module,init,1};
trans_init(gen,init_it,[gen_server,_,_,_,Module|_]) ->
{Module,init,1};
trans_init(gen,init_it,[gen_fsm,_,_,Module,_,_]) ->
{Module,init,1};
trans_init(gen,init_it,[gen_fsm,_,_,_,Module|_]) ->
{Module,init,1};
trans_init(gen,init_it,[gen_event|_]) ->
{gen_event,init_it,6};
trans_init(M, F, A) when is_atom(M), is_atom(F) ->
{M,F,length(A)}.
%% -----------------------------------------------------
%% Generate a crash report.
%% -----------------------------------------------------
crash_report(exit, normal, _) -> ok;
crash_report(exit, shutdown, _) -> ok;
crash_report(exit, {shutdown,_}, _) -> ok;
crash_report(Class, Reason, StartF) ->
OwnReport = my_info(Class, Reason, StartF),
LinkReport = linked_info(self()),
Rep = [OwnReport,LinkReport],
error_logger:error_report(crash_report, Rep).
my_info(Class, Reason, []) ->
my_info_1(Class, Reason);
my_info(Class, Reason, StartF) ->
[{initial_call, StartF}|my_info_1(Class, Reason)].
my_info_1(Class, Reason) ->
[{pid, self()},
get_process_info(self(), registered_name),
{error_info, {Class,Reason,erlang:get_stacktrace()}},
get_ancestors(self()),
get_process_info(self(), messages),
get_process_info(self(), links),
get_cleaned_dictionary(self()),
get_process_info(self(), trap_exit),
get_process_info(self(), status),
get_process_info(self(), heap_size),
get_process_info(self(), stack_size),
get_process_info(self(), reductions)
].
-spec get_ancestors(pid()) -> {'ancestors', [pid()]}.
get_ancestors(Pid) ->
case get_dictionary(Pid,'$ancestors') of
{'$ancestors',Ancestors} ->
{ancestors,Ancestors};
_ ->
{ancestors,[]}
end.
get_cleaned_dictionary(Pid) ->
case get_process_info(Pid,dictionary) of
{dictionary,Dict} -> {dictionary,clean_dict(Dict)};
_ -> {dictionary,[]}
end.
clean_dict([{'$ancestors',_}|Dict]) ->
clean_dict(Dict);
clean_dict([{'$initial_call',_}|Dict]) ->
clean_dict(Dict);
clean_dict([E|Dict]) ->
[E|clean_dict(Dict)];
clean_dict([]) ->
[].
get_dictionary(Pid,Tag) ->
case get_process_info(Pid,dictionary) of
{dictionary,Dict} ->
case lists:keysearch(Tag,1,Dict) of
{value,Value} -> Value;
_ -> undefined
end;
_ ->
undefined
end.
linked_info(Pid) ->
make_neighbour_reports1(neighbours(Pid)).
make_neighbour_reports1([P|Ps]) ->
ReportBody = make_neighbour_report(P),
%%
%% Process P might have been deleted.
%%
case lists:member(undefined, ReportBody) of
true ->
make_neighbour_reports1(Ps);
false ->
[{neighbour, ReportBody}|make_neighbour_reports1(Ps)]
end;
make_neighbour_reports1([]) ->
[].
make_neighbour_report(Pid) ->
[{pid, Pid},
get_process_info(Pid, registered_name),
get_initial_call(Pid),
get_process_info(Pid, current_function),
get_ancestors(Pid),
get_process_info(Pid, messages),
get_process_info(Pid, links),
get_cleaned_dictionary(Pid),
get_process_info(Pid, trap_exit),
get_process_info(Pid, status),
get_process_info(Pid, heap_size),
get_process_info(Pid, stack_size),
get_process_info(Pid, reductions)
].
get_initial_call(Pid) ->
case get_dictionary(Pid, '$initial_call') of
{'$initial_call', {M, F, A}} ->
{initial_call, {M, F, make_dummy_args(A, [])}};
_ ->
get_process_info(Pid, initial_call)
end.
%% neighbours(Pid) = list of Pids
%%
%% Get the neighbours of Pid. A neighbour is a process which is
%% linked to Pid and does not trap exit; or a neigbour of a
%% neighbour etc.
%%
%% A breadth-first search is performed.
-spec neighbours(pid()) -> [pid()].
neighbours(Pid) ->
{_, Visited} = visit(adjacents(Pid), {max_neighbours(), [Pid]}),
lists:delete(Pid, Visited).
max_neighbours() -> 15.
%%
%% visit(Ps, {N, Vs}) = {N0, V0s}
%%
%% A breadth-first search of neighbours.
%% Ps processes,
%% Vs visited processes,
%% N max number to visit.
%%
visit([P|Ps], {N, Vs} = NVs) when N > 0 ->
case lists:member(P, Vs) of
false -> visit(adjacents(P), visit(Ps, {N-1, [P|Vs]}));
true -> visit(Ps, NVs)
end;
visit(_, {_N, _Vs} = NVs) ->
NVs.
%%
%% adjacents(Pid) = AdjacencyList
%%
-spec adjacents(pid()) -> [pid()].
adjacents(Pid) ->
case catch proc_info(Pid, links) of
{links, Links} -> no_trap(Links);
_ -> []
end.
no_trap([P|Ps]) ->
case catch proc_info(P, trap_exit) of
{trap_exit, false} -> [P|no_trap(Ps)];
_ -> no_trap(Ps)
end;
no_trap([]) ->
[].
get_process_info(Pid, Tag) ->
translate_process_info(Tag, catch proc_info(Pid, Tag)).
translate_process_info(registered_name, []) ->
{registered_name, []};
translate_process_info(_ , {'EXIT', _}) ->
undefined;
translate_process_info(_, Result) ->
Result.
%%% -----------------------------------------------------------
%%% Misc. functions
%%% -----------------------------------------------------------
get_my_name() ->
case proc_info(self(),registered_name) of
{registered_name,Name} -> Name;
_ -> self()
end.
-spec get_ancestors() -> [pid()].
get_ancestors() ->
case get('$ancestors') of
A when is_list(A) -> A;
_ -> []
end.
proc_info(Pid,Item) when node(Pid) =:= node() ->
process_info(Pid,Item);
proc_info(Pid,Item) ->
case lists:member(node(Pid),nodes()) of
true ->
check(rpc:call(node(Pid), erlang, process_info, [Pid, Item]));
_ ->
hidden
end.
check({badrpc,nodedown}) -> undefined;
check({badrpc,Error}) -> Error;
check(Res) -> Res.
%%% -----------------------------------------------------------
%%% Format (and write) a generated crash info structure.
%%% -----------------------------------------------------------
-spec format(CrashReport) -> string() when
CrashReport :: [term()].
format([OwnReport,LinkReport]) ->
OwnFormat = format_report(OwnReport),
LinkFormat = format_report(LinkReport),
S = io_lib:format(" crasher:~n~s neighbours:~n~s",[OwnFormat,LinkFormat]),
lists:flatten(S).
format_report(Rep) when is_list(Rep) ->
format_rep(Rep);
format_report(Rep) ->
io_lib:format("~p~n", [Rep]).
format_rep([{initial_call,InitialCall}|Rep]) ->
[format_mfa(InitialCall)|format_rep(Rep)];
format_rep([{error_info,{Class,Reason,StackTrace}}|Rep]) ->
[format_exception(Class, Reason, StackTrace)|format_rep(Rep)];
format_rep([{Tag,Data}|Rep]) ->
[format_tag(Tag, Data)|format_rep(Rep)];
format_rep(_) ->
[].
format_exception(Class, Reason, StackTrace) ->
PF = pp_fun(),
StackFun = fun(M, _F, _A) -> (M =:= erl_eval) or (M =:= ?MODULE) end,
%% EI = " exception: ",
EI = " ",
[EI, lib:format_exception(1+length(EI), Class, Reason,
StackTrace, StackFun, PF), "\n"].
format_mfa({M,F,Args}=StartF) ->
try
A = length(Args),
[" initial call: ",atom_to_list(M),$:,atom_to_list(F),$/,
integer_to_list(A),"\n"]
catch
error:_ ->
format_tag(initial_call, StartF)
end.
pp_fun() ->
fun(Term, I) ->
io_lib:format("~." ++ integer_to_list(I) ++ "p", [Term])
end.
format_tag(Tag, Data) ->
io_lib:format(" ~p: ~80.18p~n", [Tag, Data]).
