From 581b6954d344eaca2bfcdab663019796e852c778 Mon Sep 17 00:00:00 2001 From: Jan Uhlig Date: Wed, 1 Sep 2021 14:01:47 +0200 Subject: Update docs and modernize examples * Use the map form for transport options everywhere * Remove mentions of the list form for transport options * Use a state enter call instead of gen_statem:enter_loop/4 and proc_lib:start_link/3 in the tcp_reverse example * Take care of different EOLs in the tcp_reverse example * Mention state enter calls, the next_event action, and {continue, ...} in the docs for how to use gen_statem and gen_server --- doc/src/guide/listeners.asciidoc | 25 ++++++++++++------------- doc/src/guide/protocols.asciidoc | 30 ++++++++++++++++++++++-------- doc/src/guide/ssl_auth.asciidoc | 4 ++-- 3 files changed, 36 insertions(+), 23 deletions(-) (limited to 'doc/src/guide') diff --git a/doc/src/guide/listeners.asciidoc b/doc/src/guide/listeners.asciidoc index 779497c..3e7254d 100644 --- a/doc/src/guide/listeners.asciidoc +++ b/doc/src/guide/listeners.asciidoc @@ -19,7 +19,6 @@ A listener can be started and stopped at will. When starting a listener, a number of different settings are required: * A name to identify it locally and be able to interact with it. -* The number of acceptors in the pool. * A transport handler and its associated options. * A protocol handler and its associated options. @@ -43,8 +42,8 @@ to the `echo_protocol` handler. [source,erlang] {ok, _} = ranch:start_listener(tcp_echo, - ranch_tcp, [{port, 5555}], - echo_protocol, [] + ranch_tcp, #{socket_opts => [{port, 5555}]}, + echo_protocol, [] ). You can try this out by compiling and running the `tcp_echo` example in the @@ -142,8 +141,8 @@ argument is the name of the listener you gave in `ranch:start_listener/5`. [source,erlang] {ok, _} = ranch:start_listener(tcp_echo, - ranch_tcp, [{port, 0}], - echo_protocol, [] + ranch_tcp, #{socket_opts => [{port, 0}]}, + echo_protocol, [] ). Port = ranch:get_port(tcp_echo). @@ -238,8 +237,8 @@ overloaded and ensuring all the connections are handled optimally. [source,erlang] {ok, _} = ranch:start_listener(tcp_echo, - ranch_tcp, #{socket_opts => [{port, 5555}], max_connections => 100}, - echo_protocol, [] + ranch_tcp, #{socket_opts => [{port, 5555}], max_connections => 100}, + echo_protocol, [] ). You can disable this limit by setting its value to the atom `infinity`. @@ -248,8 +247,8 @@ You can disable this limit by setting its value to the atom `infinity`. [source,erlang] {ok, _} = ranch:start_listener(tcp_echo, - ranch_tcp, #{socket_opts => [{port, 5555}], max_connections => infinity}, - echo_protocol, [] + ranch_tcp, #{socket_opts => [{port, 5555}], max_connections => infinity}, + echo_protocol, [] ). The maximum number of connections is a soft limit. In practice, it @@ -305,8 +304,8 @@ measure to find the best value for your application. [source,erlang] {ok, _} = ranch:start_listener(tcp_echo, - ranch_tcp, [{port, 5555}, {num_acceptors, 42}], - echo_protocol, [] + ranch_tcp, #{socket_opts => [{port, 5555}], num_acceptors => 42}, + echo_protocol, [] ). === Customizing the number of connection supervisors @@ -325,8 +324,8 @@ processes. [source,erlang] {ok, _} = ranch:start_listener(tcp_echo, - ranch_tcp, #{socket_opts => [{port, 5555}], num_conns_sups => 42}], - echo_protocol, [] + ranch_tcp, #{socket_opts => [{port, 5555}], num_conns_sups => 42}, + echo_protocol, [] ). === When running out of file descriptors diff --git a/doc/src/guide/protocols.asciidoc b/doc/src/guide/protocols.asciidoc index 73a0bf5..8f55cea 100644 --- a/doc/src/guide/protocols.asciidoc +++ b/doc/src/guide/protocols.asciidoc @@ -59,7 +59,7 @@ loop(Socket, Transport) -> end. ---- -=== Using gen_statem +=== Using gen_statem and gen_server Special processes like the ones that use the `gen_statem` or `gen_server` behaviours have the particularity of having their `start_link` call not @@ -67,12 +67,21 @@ return until the `init` function returns. This is problematic, because you won't be able to call `ranch:handshake/1,2` from the `init` callback as this would cause a deadlock to happen. -Use the `gen_statem:enter_loop/4` function. It allows you to start your process -normally (although it must be started with `proc_lib` like all special -processes), then perform any needed operations before falling back into -the normal `gen_statem` execution loop. +This problem can be addressed in several ways. -.Use a gen_statem for protocol handling +==== gen_statem + +* Use state enter calls and place the `ranch:handshake/1,2` call in the enter + clause of the initial state. Check the `tcp_reverse` example for a complete + example. +* Use a `next_event` action in the return from `init/1` and place the + `ranch:handshake/1,2` call in the clause handling the event in the initial + state. +* Use the `gen_statem:enter_loop/4` function and start your process with + `proc_lib:spawn_link/3` or `proc_lib:start_link/3,4,5`. See below for an + example. + +.Using gen_statem:enter_loop/4 to start a protocol [source,erlang] ---- @@ -87,7 +96,7 @@ the normal `gen_statem` execution loop. start_link(Ref, Transport, Opts) -> {ok, proc_lib:spawn_link(?MODULE, init, [{Ref, Transport, Opts}])}. -init({Ref, Transport, _Opts = []}) -> +init({Ref, Transport, _Opts}) -> %% Perform any required state initialization here. {ok, Socket} = ranch:handshake(Ref), ok = Transport:setopts(Socket, [{active, once}]), @@ -96,4 +105,9 @@ init({Ref, Transport, _Opts = []}) -> %% Other gen_statem callbacks here. ---- -Check the `tcp_reverse` example for a complete example. +==== gen_server + +* Use `{continue, Continue}` in the return from `init/1` and place the + `ranch:handshake/1,2` call in a corresponding `handle_continue/2` clause. +* Use the `gen_server:enter_loop/3` function and start your process with + `proc_lib:spawn_link/3` or `proc_lib:start_link/3,4,5`. diff --git a/doc/src/guide/ssl_auth.asciidoc b/doc/src/guide/ssl_auth.asciidoc index de16107..1ae91e4 100644 --- a/doc/src/guide/ssl_auth.asciidoc +++ b/doc/src/guide/ssl_auth.asciidoc @@ -50,12 +50,12 @@ the listener to enable this behavior. [source,erlang] {ok, _} = ranch:start_listener(my_ssl, - ranch_ssl, [ + ranch_ssl, #{socket_opts => [ {port, SSLPort}, {certfile, PathToCertfile}, {cacertfile, PathToCACertfile}, {verify, verify_peer} - ], + ]}, my_protocol, [] ). -- cgit v1.2.3