IdleTimeout

A simple mechanism to timeout idle Elixir processes - for example a GenServer - after a given period of inactivity.

Design goals

• Good interface
• Minimal overhead
• Obvious implementation

Interface

Setup the timeout watchdog in GenServer.init/3:

IdleTimeout.start __MODULE__, 2000

First argument must be any unique ID, second argument is the first / default timeout. Your GenServer now has to ping the watchdog to prevent timeout:

IdleTimeout.ping __MODULE__

This will renew the last / default timeout. Optionally a new timeout can be given:

IdleTimeout.ping __MODULE__, 1000

Timeout only ever will get expanded, not shortened by later, shorter intervals.

Limitation

Doesn't work too well with short timeouts. Should be fine with anyting in the seconds range. My own usecase is several minutes.

Installation

If available in Hex, the package can be installed by adding idle_timeout_ex to your list of dependencies in mix.exs:

def deps do
  [{:idle_timeout_ex, "~> 0.1.0"}]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/idle_timeout_ex.