The idea of referencing processes by their PIDs gets old quickly. Fortunately, there are a number of alternatives.
The simplest is local naming. We assign a name that is unique for all OTP processes on our node, and then we use that name instead of the PID whenever we reference it. To create a locally named process, we use the name: option when we start the server:
| » | iex> { :ok, pid } = GenServer.start_link(Sequence.Server, 100, name: :seq) |
| | {:ok,#PID<0.58.0>} |
| | iex> GenServer.call(:seq, :next_number) |
| | 100 |
| | iex> GenServer.call(:seq, :next_number) |
| | 101 |
| | iex> :sys.get_status :seq |
| | {:status, #PID<0.69.0>, {:module, :gen_server}, |
| | [["$ancestors": [#PID<0.58.0>], |
| | "$initial_call": {Sequence.Server, :init, 1}], |
| | :running, #PID<0.58.0>, [], |
| | [header: 'Status for generic server seq', |
| | data: [{'Status', :running}, |
| | {'Parent', #PID<0.58.0>}, |
| | {'Logged events', []}], |
| | data: [{'State', "My current state is '102', and I'm happy"}]]]} |