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POgen_server closing listening socket
 

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    <p>What I'm trying to do is have a gen_server process accept a new client and immediately spawn a new child to handle the next one. The issue that I'm seeing is that when the socket is finished and consequentially terminates, it also closes the listening socket and I can't figure out why, even though it no longer references it.</p> <p>Any idea what I am doing wrong?</p> <p>gen_server:</p> <pre><code>-module(simple_tcp). -behaviour(gen_server). %% API -export([start_link/1, stop/0, start/0, start/1]). %% gen-server callbacks -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). -define(SERVER, ?MODULE). -define(DEFAULT_PORT, 1055). -record(state, {port, lsock}). start_link({port, Port}) -&gt; gen_server:start_link(?MODULE, [{port, Port}], []); start_link({socket, Socket}) -&gt; gen_server:start_link(?MODULE, [{socket, Socket}], []). start({port, Port}) -&gt; simple_tcp_sup:start_child({port, Port}); start({socket, Socket}) -&gt; simple_tcp_sup:start_child({socket, Socket}). start() -&gt; start({port, ?DEFAULT_PORT}). stop() -&gt; gen_server:cast(?SERVER, stop). % Callback functions init([{port, Port}]) -&gt; {ok, LSock} = gen_tcp:listen(Port, [{active, true},{reuseaddr, true}]), init([{socket, LSock}]); init([{socket, Socket}]) -&gt; io:fwrite("Starting server with socket: ~p~n", [self()]), {ok, Port} = inet:port(Socket), {ok, #state{port=Port, lsock=Socket}, 0}. handle_call(_Msg, _From, State) -&gt; {noreply, State}. handle_cast(stop, State) -&gt; {stop, ok, State}. handle_info({tcp, Socket, RawData}, State) -&gt; gen_tcp:send(Socket, io_lib:fwrite("Received raw data: ~p~n", [RawData])), {noreply, State}; handle_info({tcp_error, _Socket, Reason}, State) -&gt; io:fwrite("Error: ~p~n", [Reason]), {stop, normal, State}; handle_info(timeout, #state{lsock = LSock} = State) -&gt; case gen_tcp:accept(LSock) of {ok, Sock} -&gt; io:fwrite("Accepting connection...~p~n", [self()]), start({socket, LSock}), {noreply, #state{lsock=Sock}}; {error, Reason} -&gt; io:fwrite("Error: ~p, ~p~n", [Reason, self()]), {stop, normal, State} end; handle_info({tcp_closed, _Port}, State) -&gt; io:fwrite("Socket closed: ~p~n", [self()]), simple_tcp_sup:kill_child(self()), {stop, normal, State}. terminate(_Reason, _State) -&gt; io:fwrite("Shutting down server: ~p~n", [self()]), ok. code_change(_OldVsn, State, _Extra) -&gt; {ok, State}. </code></pre> <p>supervisor:</p> <pre><code>-module(simple_tcp_sup). -behaviour(supervisor). -export([start_link/0, start_child/1 ]). -export([init/1]). -define(SERVER, ?MODULE). start_link() -&gt; supervisor:start_link({local, ?SERVER}, ?MODULE, []). start_child({socket, Socket}) -&gt; io:fwrite("Spawning child with socket...~n"), supervisor:start_child(?SERVER, [{socket, Socket}]); start_child({port, Port}) -&gt; io:fwrite("Spawning child with port...~n"), supervisor:start_child(?SERVER, [{port, Port}]). init([]) -&gt; Element = {simple_tcp, {simple_tcp, start_link, []}, temporary, brutal_kill, worker, [simple_tcp]}, Children = [Element], RestartStrategy = {simple_one_for_one, 0, 1}, {ok, {RestartStrategy, Children}}. </code></pre>
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    1. USAdam Lindberg
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    1. COIt is not very helpful for future readers of your question if you have all code in a ephemeral external storage like pastebin. Edit your question to contain the important parts of the code
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      1. USPeer Stritzinger
    2. CO@Peer: There, I edited it for you.
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      1. USAdam Lindberg
    3. CO@Adam: great ... I was in a hurry so I only had time for the educate the new user part ;-)
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      1. USPeer Stritzinger
 

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