主控引擎重新启动策略和子规范

Question

我正在阅读rabbitmq的supervisor2.erl,rabbit_channel_sup_sup.erl, rabbit_channel_sup.erl源代码。

当childspec的start参数为"temporary"时，表示该子进程在任何原因退出后都不会重启，对吗？

当start参数为"temporary"时，每个重新启动参数one-for-one, one-for-all,one-for-rest,simple-one-for-one都没有区别。因为代码运行结果是相同的。是对的吗？

以下代码来自supervisor2.erl文件

do_restart({permanent = RestartType, Delay}, Reason, Child, State) ->
    do_restart_delay({RestartType, Delay}, Reason, Child, State);
do_restart(permanent, Reason, Child, State) ->
    report_error(child_terminated, Reason, Child, State#state.name),
    restart(Child, State);
do_restart(Type, normal, Child, State) ->
    del_child_and_maybe_shutdown(Type, Child, State);
do_restart({RestartType, Delay}, {shutdown, restart} = Reason, Child, State)
  when RestartType =:= transient orelse RestartType =:= intrinsic ->
    do_restart_delay({RestartType, Delay}, Reason, Child, State);
do_restart(Type, {shutdown, _}, Child, State) ->
    del_child_and_maybe_shutdown(Type, Child, State);
do_restart(Type, shutdown, Child = #child{child_type = supervisor}, State) ->
    del_child_and_maybe_shutdown(Type, Child, State);
do_restart({RestartType, Delay}, Reason, Child, State)
  when RestartType =:= transient orelse RestartType =:= intrinsic ->
    do_restart_delay({RestartType, Delay}, Reason, Child, State);
do_restart(Type, Reason, Child, State) when Type =:= transient orelse
                                            Type =:= intrinsic ->
    report_error(child_terminated, Reason, Child, State#state.name),
    restart(Child, State);
do_restart(temporary, Reason, Child, State) ->  %%<<----attention here, just report_error,not calling restart child function
    report_error(child_terminated, Reason, Child, State#state.name),
    NState = state_del_child(Child, State),
    {ok, NState}.

Answer 1

临时子进程永远不会重启，这是真的。但重启策略仍然在决定主管行为方面发挥作用- all-for-one策略将杀死所有孩子(不会重启，因为他们是暂时的)，而one_for_one不会杀死任何其他孩子。基本上，这些重启策略告诉管理程序如何处理其他进程(其他进程是未死的进程)，因此是有区别的。