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Update documentation for embedded listeners

juhlig 5 years ago
parent
commit
f6d1fae694
1 changed files with 20 additions and 21 deletions
  1. 20 21
      doc/src/guide/embedded.asciidoc

+ 20 - 21
doc/src/guide/embedded.asciidoc

@@ -5,44 +5,43 @@ in your supervision tree. This allows for greater fault tolerance
 control by permitting the shutdown of a listener due to the
 control by permitting the shutdown of a listener due to the
 failure of another part of the application and vice versa.
 failure of another part of the application and vice versa.
 
 
+However, just as for non-embedded listeners that were started via
+`ranch:start_listener/5`, it is required that the `ranch` application
+is running before you can start embedded listeners. Furthermore,
+this also means that embedded listeners will restart when `ranch_sup` fails.
+
+WARNING: By using embedded mode, it is possible to start a listener with the same name
+as an already existing listener. This will corrupt the information Ranch
+keeps for that listener, so you should take care to ensure unique listener
+names yourself. A good way to achieve this is by combining the embedded
+listener's name with `?MODULE`, or the name of the application it is used
+in.
+
 === Embedding
 === Embedding
 
 
 To embed Ranch in your application you can simply add the child specs
 To embed Ranch in your application you can simply add the child specs
 to your supervision tree. This can all be done in the `init/1` function
 to your supervision tree. This can all be done in the `init/1` function
 of one of your application supervisors.
 of one of your application supervisors.
 
 
-Ranch requires at the minimum two kinds of child specs for embedding.
-First, you need to add `ranch_sup` to your supervision tree, only once,
-regardless of the number of listeners you will use. Then you need to
-add the child specs for each listener.
-
 Ranch has a convenience function for getting the listeners child specs
 Ranch has a convenience function for getting the listeners child specs
 called `ranch:child_spec/5`, that works like `ranch:start_listener/5`,
 called `ranch:child_spec/5`, that works like `ranch:start_listener/5`,
 except that it doesn't start anything, it only returns child specs.
 except that it doesn't start anything, it only returns child specs.
 
 
-As for `ranch_sup`, the child spec is simple enough to not require a
-convenience function.
-
-The following example adds both `ranch_sup` and one listener to another
-application's supervision tree.
+The following example adds one listener to another application's
+supervision tree.
 
 
 .Embed Ranch directly in your supervision tree
 .Embed Ranch directly in your supervision tree
 
 
 [source,erlang]
 [source,erlang]
 ----
 ----
 init([]) ->
 init([]) ->
-	RanchSupSpec = {ranch_sup, {ranch_sup, start_link, []},
-		permanent, 5000, supervisor, [ranch_sup]},
-	ListenerSpec = ranch:child_spec(echo, 100,
-		ranch_tcp, [{port, 5555}],
+	ListenerSpec = ranch:child_spec({?MODULE, echo},
+		ranch_tcp, #{socket_opts => [{port, 5555}]},
 		echo_protocol, []
 		echo_protocol, []
 	),
 	),
-	{ok, {{one_for_one, 10, 10}, [RanchSupSpec, ListenerSpec]}}.
+	{ok, {#{}, [ListenerSpec]}}.
 ----
 ----
 
 
-Remember, you can add as many listener child specs as needed, but only
-one `ranch_sup` spec!
-
-It is recommended that your architecture makes sure that all listeners
-are restarted if `ranch_sup` fails. See the Ranch internals chapter for
-more details on how Ranch does it.
+Embedded listeners cannot be stopped via `ranch:stop_listener/1`. Instead,
+are to be stopped as part of the shutdown of your application's supervison
+tree.