Start by building a simple version of GenServer that supports both synchronous and asynchronous functionality.
A GenServer can maintain a state.
A GenServer has three types of “handles”:
handle_call: synchronous message handlinghandle_cast: asynchronous message handlinghandle_info: non-GenServer-specific message
The chapter provides a periodic clean-up timer as an example.
On to the GenServer-powered go-do server exercise.
Notable Notes and Quotes
- The code
Module.__info__(:functions)returns a list of public module functions and their arity. - “It’s a good practice to always specify the @impl attribute for every callback function you define in your modules.”
- If you are going to have only a single instance of a GenServer, you should register the name.
This allows you to refer to the process by name vs pid.
See
key_value_gen_server_named.exin My Github under Chapter 6.
My Github repository. Book samples Github code samples.
Quotes are excerpts From Elixir in Action, Third Edition, Sasa Juric. All notes and comments are my own opinion. Follow me at @rgacote@genserver.social