%-*-Mode:erlang;coding:utf-8;tab-width:4;c-basic-offset:4;indent-tabs-mode:()-*- % ex: set ft=erlang fenc=utf-8 sts=4 ts=4 sw=4 et nomod: %%% %%%------------------------------------------------------------------------ %%% @doc %%% ==CPG Supervisor Spawn.== %%% Helper process for cpg_supervisor. %%% @end %%% %%% MIT License %%% %%% Copyright (c) 2013-2020 Michael Truog %%% %%% Permission is hereby granted, free of charge, to any person obtaining a %%% copy of this software and associated documentation files (the "Software"), %%% to deal in the Software without restriction, including without limitation %%% the rights to use, copy, modify, merge, publish, distribute, sublicense, %%% and/or sell copies of the Software, and to permit persons to whom the %%% Software is furnished to do so, subject to the following conditions: %%% %%% The above copyright notice and this permission notice shall be included in %%% all copies or substantial portions of the Software. %%% %%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR %%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, %%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE %%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER %%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING %%% FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER %%% DEALINGS IN THE SOFTWARE. %%% %%% @author Michael Truog %%% @copyright 2013-2020 Michael Truog %%% @version 1.8.1 {@date} {@time} %%%------------------------------------------------------------------------ -module(supervisor_cpg_spawn). -author('mjtruog at protonmail dot com'). -behaviour(gen_server). %% external interface -export([start_link/4, start_nomad_child/4, start_remote_child/2, start_child/2, restart_child/2, delete_child/2, terminate_child/2, which_children/1, count_children/1, cpg_name/1]). %% gen_server callbacks -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). -include("cpg_constants.hrl"). -record(state_nomad, { name, pid, restarts = [], max_r, max_t, child_spec }). -record(state, { parent_sup, child_sup, nomads = dict:new() }). %%%------------------------------------------------------------------------ %%% External interface functions %%%------------------------------------------------------------------------ start_link(SpawnName, MaxR, MaxT, ChildSpecs) -> gen_server:start_link(SpawnName, ?MODULE, [self(), MaxR, MaxT, ChildSpecs], []). start_nomad_child(_, MaxR, MaxT, _) when is_integer(MaxR) =:= false; is_integer(MaxT) =:= false -> erlang:exit(badarg); start_nomad_child(Name, MaxR, MaxT, ChildSpec) when MaxR >= 0, MaxT > 0 -> gen_server:call(cpg_random_pid(Name), {start_nomad_child, Name, MaxR, MaxT, ChildSpec}, infinity). start_remote_child(Name, ChildSpec) -> gen_server:call(cpg_random_pid(Name), {start_child, ChildSpec}, infinity). start_child(Name, ChildSpec) -> gen_server:call(cpg_name(Name), {start_child, ChildSpec}, infinity). terminate_child(Name, Id) -> gen_server:call(cpg_name(Name), {terminate_child, Id}, infinity). delete_child(Name, Id) -> gen_server:call(cpg_name(Name), {delete_child, Id}, infinity). restart_child(Name, Id) -> gen_server:call(cpg_name(Name), {restart_child, Id}, infinity). which_children(Name) -> gen_server:call(cpg_name(Name), which_children, infinity). count_children(Name) -> gen_server:call(cpg_name(Name), count_children, infinity). cpg_name({global, _, _, _}) -> erlang:exit(badarg); cpg_name({local, _, _, Instances}) when is_integer(Instances) -> erlang:exit(badarg); cpg_name({global, _, _}) -> erlang:exit(badarg); cpg_name({local, _, Instances}) when is_integer(Instances) -> erlang:exit(badarg); cpg_name({local, _, _} = Name) -> {via, cpg, Name}; cpg_name({global, _}) -> erlang:exit(badarg); cpg_name({local, _} = Name) -> {via, cpg, Name}; cpg_name({_, _} = Name) -> {via, cpg, Name}; cpg_name(Name) -> {via, cpg, Name}. %%%------------------------------------------------------------------------ %%% Callback functions from gen_server %%%------------------------------------------------------------------------ init([ParentSup, MaxR, MaxT, ChildSpecs]) -> self() ! {child_sup, MaxR, MaxT, ChildSpecs}, {ok, #state{parent_sup = ParentSup}}. handle_call({start_nomad_child, Name, MaxR, MaxT, {Id, StartFunc, _, Shutdown, Type, Modules} = ChildSpec}, _, #state{child_sup = ChildSup, nomads = Nomads} = State) -> NomadChildSpec = {Id, StartFunc, temporary, Shutdown, Type, Modules}, case supervisor:start_child(ChildSup, NomadChildSpec) of {ok, NomadChild} = Success -> NomadState = #state_nomad{name = Name, pid = NomadChild, max_r = MaxR, max_t = MaxT, child_spec = ChildSpec}, MonitorRef = erlang:monitor(process, NomadChild), {reply, Success, State#state{nomads = dict:store(MonitorRef, NomadState, Nomads)}}; {error, _} = Error -> {reply, Error, State} end; handle_call({start_child, ChildSpec}, _, #state{child_sup = ChildSup} = State) -> {reply, supervisor:start_child(ChildSup, ChildSpec), State}; handle_call({terminate_child, Id}, _, #state{child_sup = ChildSup} = State) -> {reply, supervisor:terminate_child(ChildSup, Id), State}; handle_call({delete_child, Id}, _, #state{child_sup = ChildSup} = State) -> {reply, supervisor:delete_child(ChildSup, Id), State}; handle_call({restart_child, Id}, _, #state{child_sup = ChildSup} = State) -> {reply, supervisor:restart_child(ChildSup, Id), State}; handle_call(which_children, _, #state{child_sup = ChildSup} = State) -> {reply, supervisor:which_children(ChildSup), State}; handle_call(count_children, _, #state{child_sup = ChildSup} = State) -> {reply, supervisor:count_children(ChildSup), State}; handle_call(_, _, State) -> {stop, unknown_call, error, State}. handle_cast({restart_nomad_child, #state_nomad{child_spec = {Id, StartFunc, _, Shutdown, Type, Modules}} = NomadState}, #state{child_sup = ChildSup, nomads = Nomads} = State) -> NomadChildSpec = {Id, StartFunc, temporary, Shutdown, Type, Modules}, case supervisor:start_child(ChildSup, NomadChildSpec) of {ok, NomadChild} -> NomadStateNew = NomadState#state_nomad{pid = NomadChild}, MonitorRef = erlang:monitor(process, NomadChild), {noreply, State#state{nomads = dict:store(MonitorRef, NomadStateNew, Nomads)}}; {error, Reason} -> report_error(start_error, Reason, NomadState#state_nomad{pid = undefined}), {noreply, State} end; handle_cast(_, State) -> {stop, unknown_cast, State}. handle_info({child_sup, MaxR, MaxT, ChildSpecs}, #state{parent_sup = ParentSup} = State) -> case supervisor:start_child(ParentSup, {supervisor_cpg_sup, {supervisor_cpg_sup, start_link, [MaxR, MaxT, ChildSpecs]}, permanent, infinity, supervisor, [supervisor_cpg_sup]}) of {ok, ChildSup} -> {noreply, State#state{child_sup = ChildSup}}; {ok, ChildSup, _} -> {noreply, State#state{child_sup = ChildSup}}; {error, Reason} -> {stop, Reason, State} end; handle_info({'DOWN', MonitorRef, process, _Object, Reason}, #state{nomads = Nomads} = State) -> % supervisor behaviour logs this as child_terminated nomad_restart(Reason, dict:fetch(MonitorRef, Nomads)), {noreply, State#state{nomads = dict:erase(MonitorRef, Nomads)}}; handle_info(_, State) -> {stop, unknown_info, State}. terminate(_, _) -> ok. code_change(_, State, _) -> {ok, State}. %%%------------------------------------------------------------------------ %%% Private functions %%%------------------------------------------------------------------------ cpg_random_pid({global, _, _, _}) -> erlang:exit(badarg); cpg_random_pid({local, _, _, Instances}) when is_integer(Instances) -> erlang:exit(badarg); cpg_random_pid({global, _, _}) -> erlang:exit(badarg); cpg_random_pid({local, _, Instances}) when is_integer(Instances) -> erlang:exit(badarg); cpg_random_pid({local, Scope, GroupName}) -> cpg_random_pid(Scope, GroupName, undefined); cpg_random_pid({global, _}) -> erlang:exit(badarg); cpg_random_pid({local, GroupName}) -> cpg_random_pid(?DEFAULT_SCOPE, GroupName, undefined); cpg_random_pid({Scope, GroupName}) -> cpg_random_pid(Scope, GroupName, undefined); cpg_random_pid(GroupName) -> cpg_random_pid(?DEFAULT_SCOPE, GroupName, undefined). cpg_random_pid({global, _, _, _}, _) -> erlang:exit(badarg); cpg_random_pid({local, _, _, Instances}, _) when is_integer(Instances) -> erlang:exit(badarg); cpg_random_pid({global, _, _}, _) -> erlang:exit(badarg); cpg_random_pid({local, _, Instances}, _) when is_integer(Instances) -> erlang:exit(badarg); cpg_random_pid({local, Scope, GroupName}, Exclude) -> cpg_random_pid(Scope, GroupName, Exclude); cpg_random_pid({global, _}, _) -> erlang:exit(badarg); cpg_random_pid({local, GroupName}, Exclude) -> cpg_random_pid(?DEFAULT_SCOPE, GroupName, Exclude); cpg_random_pid({Scope, GroupName}, Exclude) -> cpg_random_pid(Scope, GroupName, Exclude); cpg_random_pid(GroupName, Exclude) -> cpg_random_pid(?DEFAULT_SCOPE, GroupName, Exclude). cpg_random_pid(Scope, GroupName, undefined) -> case cpg:get_random_pid(Scope, GroupName) of {ok, _, Pid} -> Pid; {error, _} -> undefined end; cpg_random_pid(Scope, GroupName, Exclude) -> case cpg:get_random_pid(Scope, GroupName, Exclude) of {ok, _, Pid} -> Pid; {error, _} -> undefined end. nomad_restart(_, #state_nomad{max_r = 0}) -> ok; nomad_restart(_, #state_nomad{child_spec = {_, _, temporary, _, _, _}}) -> ok; nomad_restart(normal, #state_nomad{child_spec = {_, _, transient, _, _, _}}) -> ok; nomad_restart(shutdown, #state_nomad{child_spec = {_, _, transient, _, _, _}}) -> ok; nomad_restart({shutdown, _}, #state_nomad{child_spec = {_, _, transient, _, _, _}}) -> ok; nomad_restart(_Reason, #state_nomad{name = Name, restarts = Restarts, max_r = MaxR, max_t = MaxT} = NomadState) -> Now = timestamp(), RestartsNew = lists:dropwhile(fun(T) -> timer:now_diff(Now, T) / 1000000 > MaxT end, Restarts) ++ [Now], SupPidNext = cpg_random_pid(Name, self()), if erlang:length(RestartsNew) > MaxR -> report_error(shutdown, reached_max_restart_intensity, NomadState); SupPidNext =:= undefined -> report_error(restart_error, noproc, NomadState); true -> gen_server:cast(SupPidNext, {restart_nomad_child, NomadState#state_nomad{restarts = RestartsNew}}) end. % based on OTP supervisor code report_error(Error, Reason, #state_nomad{name = SupName} = NomadState) -> ErrorMsg = [{supervisor, {via, cpg, SupName}}, {errorContext, Error}, {reason, Reason}, {offender, extract_child(NomadState)}], error_logger:error_report(supervisor_report, ErrorMsg). % based on OTP supervisor code extract_child(#state_nomad{pid = Pid, child_spec = {Id, StartFunc, Restart, Shutdown, Type, _}}) -> [{pid, Pid}, {name, Id}, {mfargs, StartFunc}, {restart_type, Restart}, {shutdown, Shutdown}, {child_type, Type}]. -spec timestamp() -> erlang:timestamp(). timestamp() -> erlang:timestamp().