Genserver.call with timeout doesn't end up with :timeout message

Where is your timeout defined?

The 50 I believe

No, it’s should not be like that…

It’s when You return from any call that You specify timeout.

like {:reply, state, state, timeout}

But what about this?

It is not the same timeout. One is the client timeout, one is the server timeout.

Please note server handlers should also return timeout, even init.

Here is an example…

  @timeout 5 * 60 * 1_000

  @impl GenServer
  def handle_call(:get_state, _from, state), do: {:reply, state, state, @timeout}

  # Timeout handler
  @impl GenServer
  def handle_info(:timeout, state), do: stop_and_clean(state, {:shutdown, :timeout})

stop and clean is a custom function…

And how can I make this timeout?

What I actually want to use is to show a different response if the timeout happens.
Now I added the timeout to where you said, and I am getting the :timeout message.
But where I am making the call to the genserver I am still getting the result.

with {:ok, checksum} <- Checksum.calculate_checksum() do
      conn
      |> put_status(200)
      |> put_view(ChecksumView)
      |> render("checksum.json", checksum: checksum, message: "Checksum calculated successfully!")
    else
      _ ->
        conn
        |> put_status(488)
        |> put_view(ChecksumView)
        |> render("408.json")
    end

As you saw from my handle_call for :calculate I am returning {:ok, result}, but I am also seeing the :timeout message being handled.

  @impl GenServer
  def handle_info(:timeout, state) do
    {:noreply, state}
  end

What would be ideal if there is a timeout instead of getting {:ok, result} I could get something like {:error, :timeout} but If I do reply with this error and state in the handle_info then it is a bad return value.

I think I was on the right path based on this: gen_server — OTP 29.0.2 (stdlib 8.0.1)
And I think I have this problem:
https://groups.google.com/g/elixir-lang-talk/c/7tS9tX7fLpg

I tried to put the genserver call in try do but no success yet

When you do a call with a timeout this is the timeout the caller process will wait before it throws an exception. You need to rescue this exception at the call site.

The timeout in a gen_server (the one you can set in the callback of any handle) is an internal timeout that sets an amount of time the gen_server can be without receiving any message, which upon it elapsing triggers an internal message of :timeout that you can handle. This timeout is disabled whenever a message arrives in the gen_servers mailbox and needs to be set again if you wish it to trigger again.

Hey, thanks for the response!

I am trying this:

  def calculate_checksum() do
    try do
      GenServer.call(__MODULE__, :calculate, 15)
    rescue
      _ -> {:error, :timeout}
    end
  end

but no success