erlang - Receive after result not returned -

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given function:

%% @doc retrieves client's state. -spec(state(pid()) -> atom()). state(pid) when is_pid(pid) ->   case process_info(pid) of     undefined ->       undefined;     _else ->       pid ! {state, self()},       receive         {state, state} ->           state       after         1000 ->           undefined       end   end.

it works expected dead pids , alive clients:

> client:state(a). undefined > client:state(pid). online

but reason returns pid if process pid not reply status during 1 second:

> client:state(self()). <0.172.0>

i'm expecting 'undefined' atom there. how can fix code?

this happens because receiving message sent. function running on shell process , sends {state, self()} message. right after sending message, receives message , function ends state, self() pid sent.

i hope i've not been confusing.


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