unable to reconnect to server

[Matthias Lang]

Dietmar Schaefer writes:

 > I am trying to establish a connection to a client via gen_tcp:

[...]

 > When I terminate the client and try to start it again I get
 > 
 > Error in process <0.322.0> on node 'cmmc@REDACTED' with exit value: 
 > {badarg,[{erlang,register,[test,<0.325.0>]},{test3,loop,1}]}
 > 
 > What has erlang:register to do with that ?
 > 
 > What's wrong anyway ?
 > 
 > Any hint ?

The program you posted isn't complete (it calls fill/2, but you
haven't provided fill/2), so I'll just take a guess.

register/2 is failing because you try to register the spawned process
every time a client connects. Here's the manual:

  | register(Name, P)
  | 
  | Associates the name Name with the port or process identity P. Name,
  | which must be an atom, can be used instead of a port or pid in the
  | send operator (Name ! Message).
  | 
  | Returns true.
  | 
  | Failure: badarg if P is not an active port or process, or if P is on
  | another node, or if the name Name is already in use, or if the port or
  | process is already registered (it already has a name), or if the name
  | Name is not an atom, or if Name is the atom undefined.

So, if you do this, it's going to fail the second time around:

  loop() ->
     register(test, spawn(fun() -> timer:sleep(10000) end)),
     loop().

Matthias