主管重启策略和 childspec

Question

我在看rabbitmq的supervisor2.erl,rabbit_channel_sup_sup.erl, rabbit_channel_sup.erl源码。

当childspec的启动参数为"temporary"时，表示无论任何原因退出后子进程都不会重新启动。对吗？

当启动参数为"temporary"时，每个重启参数one-for-one, one-for-all,one-for-rest,simple-one-for-one没有区别。因为代码运行结果是一样的。对吗？

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

一个临时的孩子永远不会重新启动，这是真的。但是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（不会重新启动，因为它们是临时的），而 one_for_one 不会杀死任何其他孩子。基本上，这些重启策略告诉主管如何处理其他进程（其他是没有死的进程），所以有区别。