diff options
| -rw-r--r-- | doc/src/guide/protocols.asciidoc | 36 | ||||
| -rw-r--r-- | examples/tcp_reverse/src/reverse_protocol.erl | 8 |
2 files changed, 7 insertions, 37 deletions
diff --git a/doc/src/guide/protocols.asciidoc b/doc/src/guide/protocols.asciidoc index 8060343..393c601 100644 --- a/doc/src/guide/protocols.asciidoc +++ b/doc/src/guide/protocols.asciidoc @@ -67,10 +67,7 @@ return until the `init` function returns. This is problematic, because you won't be able to call `ranch:accept_ack/1` from the `init` callback as this would cause a deadlock to happen. -There are two ways of solving this problem. - -The first, and probably the most elegant one, is to make use of the -`gen_server:enter_loop/3` function. It allows you to start your process +Use the `gen_server:enter_loop/3` 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_server` execution loop. @@ -84,14 +81,13 @@ the normal `gen_server` execution loop. -behaviour(ranch_protocol). -export([start_link/4]). --export([init/4]). +-export([init/1]). %% Exports of other gen_server callbacks here. start_link(Ref, Socket, Transport, Opts) -> - proc_lib:start_link(?MODULE, init, [Ref, Socket, Transport, Opts]). + {ok, proc_lib:spawn_link(?MODULE, init, [{Ref, Socket, Transport, Opts}])}. -init(Ref, Socket, Transport, _Opts = []) -> - ok = proc_lib:init_ack({ok, self()}), +init({Ref, Socket, Transport, _Opts = []}) -> %% Perform any required state initialization here. ok = ranch:accept_ack(Ref), ok = Transport:setopts(Socket, [{active, once}]), @@ -99,27 +95,3 @@ init(Ref, Socket, Transport, _Opts = []) -> %% Other gen_server callbacks here. ---- - -The second method involves triggering a timeout just after `gen_server:init` -ends. If you return a timeout value of `0` then the `gen_server` will call -`handle_info(timeout, _, _)` right away. - -.Use a gen_server for protocol handling, method 2 - -[source,erlang] ----- --module(my_protocol). --behaviour(gen_server). --behaviour(ranch_protocol). - -%% Exports go here. - -init([Ref, Socket, Transport]) -> - {ok, {state, Ref, Socket, Transport}, 0}. - -handle_info(timeout, State={state, Ref, Socket, Transport}) -> - ok = ranch:accept_ack(Ref), - ok = Transport:setopts(Socket, [{active, once}]), - {noreply, State}; -%% ... ----- diff --git a/examples/tcp_reverse/src/reverse_protocol.erl b/examples/tcp_reverse/src/reverse_protocol.erl index 6f7c770..2c7c15b 100644 --- a/examples/tcp_reverse/src/reverse_protocol.erl +++ b/examples/tcp_reverse/src/reverse_protocol.erl @@ -9,7 +9,6 @@ %% gen_server. -export([init/1]). --export([init/4]). -export([handle_call/3]). -export([handle_cast/2]). -export([handle_info/2]). @@ -23,16 +22,15 @@ %% API. start_link(Ref, Socket, Transport, Opts) -> - proc_lib:start_link(?MODULE, init, [Ref, Socket, Transport, Opts]). + {ok, proc_lib:spawn_link(?MODULE, init, [{Ref, Socket, Transport, Opts}])}. %% gen_server. %% This function is never called. We only define it so that %% we can use the -behaviour(gen_server) attribute. -init([]) -> {ok, undefined}. +%init([]) -> {ok, undefined}. -init(Ref, Socket, Transport, _Opts = []) -> - ok = proc_lib:init_ack({ok, self()}), +init({Ref, Socket, Transport, _Opts = []}) -> ok = ranch:accept_ack(Ref), ok = Transport:setopts(Socket, [{active, once}]), gen_server:enter_loop(?MODULE, [], |