Add '#[rocket::main]' attribute and make 'launch()' an 'async fn'.

'#[rocket::main]' works like '#[rocket::async_test]', but it uses
tokio's multithreaded scheduler.

contrib/lib/src/databases.rs

@@ -62,10 +62,12 @@
 //! #[database("sqlite_logs")]
 //! struct LogsDbConn(diesel::SqliteConnection);
 //!
-//! fn main() {
+//! #[rocket::main]
+//! async fn main() {
 //!     rocket::ignite()
 //!        .attach(LogsDbConn::fairing())
-//!        .launch();
+//!        .launch()
+//!        .await;
 //! }
 //! # } fn main() {}
 //! ```
@@ -150,7 +152,8 @@
 //! use std::collections::HashMap;
 //! use rocket::config::{Config, Environment, Value};
 //!
-//! fn main() {
+//! #[rocket::main]
+//! async fn main() {
 //!     let mut database_config = HashMap::new();
 //!     let mut databases = HashMap::new();
 //!
@@ -164,7 +167,7 @@
 //!         .finalize()
 //!         .unwrap();
 //!
-//!     rocket::custom(config).launch();
+//!     rocket::custom(config).launch().await;
 //! }
 //! # } fn main() {}
 //! ```
@@ -263,7 +266,8 @@
 //! #[database("my_db")]
 //! struct MyDatabase(diesel::SqliteConnection);
 //!
-//! fn main() {
+//! #[rocket::main]
+//! async fn main() {
 //! #     let mut db_config = HashMap::new();
 //! #     let mut databases = HashMap::new();
 //! #
@@ -278,7 +282,8 @@
 //! #
 //!     rocket::custom(config)
 //!         .attach(MyDatabase::fairing())
-//!         .launch();
+//!         .launch()
+//!         .await;
 //! }
 //! # } fn main() {}
 //! ```

contrib/lib/src/serve.rs

@@ -135,11 +135,13 @@ impl std::ops::BitOr for Options {
 /// # extern crate rocket_contrib;
 /// use rocket_contrib::serve::StaticFiles;
 ///
-/// fn main() {
+/// #[rocket::main]
+/// async fn main() {
 /// # if false {
 ///     rocket::ignite()
 ///         .mount("/public", StaticFiles::from("/static"))
-///         .launch();
+///         .launch()
+///         .await;
 /// # }
 /// }
 /// ```
@@ -161,11 +163,13 @@ impl std::ops::BitOr for Options {
 /// # extern crate rocket_contrib;
 /// use rocket_contrib::serve::StaticFiles;
 ///
-/// fn main() {
+/// #[rocket::main]
+/// async fn main() {
 /// # if false {
 ///     rocket::ignite()
 ///         .mount("/", StaticFiles::from(concat!(env!("CARGO_MANIFEST_DIR"), "/static")))
-///         .launch();
+///         .launch()
+///         .await;
 /// # }
 /// }
 /// ```
@@ -196,11 +200,13 @@ impl StaticFiles {
     /// # extern crate rocket_contrib;
     /// use rocket_contrib::serve::StaticFiles;
     ///
-    /// fn main() {
+    /// #[rocket::main]
+    /// async fn main() {
     /// # if false {
     ///     rocket::ignite()
     ///         .mount("/static", StaticFiles::from("/www/public"))
-    ///         .launch();
+    ///         .launch()
+    ///         .await;
     /// # }
     /// }
     /// ```
@@ -212,11 +218,13 @@ impl StaticFiles {
     /// # extern crate rocket_contrib;
     /// use rocket_contrib::serve::StaticFiles;
     ///
-    /// fn main() {
+    /// #[rocket::main]
+    /// async fn main() {
     /// # if false {
     ///     rocket::ignite()
     ///         .mount("/static", StaticFiles::from("/www/public").rank(30))
-    ///         .launch();
+    ///         .launch()
+    ///         .await;
     /// # }
     /// }
     /// ```
@@ -240,13 +248,15 @@ impl StaticFiles {
     /// # extern crate rocket_contrib;
     /// use rocket_contrib::serve::{StaticFiles, Options};
     ///
-    /// fn main() {
+    /// #[rocket::main]
+    /// async fn main() {
     /// # if false {
     ///     let options = Options::Index | Options::DotFiles;
     ///     rocket::ignite()
     ///         .mount("/static", StaticFiles::from("/www/public"))
     ///         .mount("/pub", StaticFiles::new("/www/public", options).rank(-1))
-    ///         .launch();
+    ///         .launch()
+    ///         .await;
     /// # }
     /// }
     /// ```

core/codegen/src/attribute/async_entry.rs

@@ -0,0 +1,83 @@
+use proc_macro::{TokenStream, Span};
+use devise::{syn, Result};
+
+use crate::proc_macro2::TokenStream as TokenStream2;
+use crate::syn_ext::syn_to_diag;
+
+#[derive(Copy, Clone)]
+enum Kind {
+    Main,
+    Test,
+}
+
+impl Kind {
+    // The name of the attribute, used for error messages
+    fn attr_name(&self) -> &'static str {
+        match self {
+            Kind::Main => "main",
+            Kind::Test => "async_test",
+        }
+    }
+
+    // Attributes to decorate the generated function with
+    fn attrs(&self) -> Option<TokenStream2> {
+        match self {
+            Kind::Main => None,
+            Kind::Test => Some(quote!{ #[test] }),
+        }
+    }
+
+    // The path to the function to call
+    fn fn_path(&self) -> TokenStream2 {
+        match self {
+            Kind::Main => quote! { rocket :: async_main },
+            Kind::Test => quote! { rocket :: async_test },
+        }
+    }
+}
+
+fn parse_input(input: TokenStream, attr_name: &str) -> Result<syn::ItemFn> {
+    let function: syn::ItemFn = syn::parse(input).map_err(syn_to_diag)
+        .map_err(|diag| diag.help(format!("`#[{}]` can only be applied to async functions", attr_name)))?;
+
+    if function.sig.asyncness.is_none() {
+        return Err(Span::call_site().error(format!("`#[{}]` can only be applied to async functions", attr_name)))
+    }
+
+    if !function.sig.inputs.is_empty() {
+        return Err(Span::call_site().error(format!("`#[{}]` can only be applied to functions with no parameters", attr_name)));
+    }
+
+    Ok(function)
+}
+
+fn _async_entry(_args: TokenStream, input: TokenStream, kind: Kind) -> Result<TokenStream> {
+    let function = parse_input(input, kind.attr_name())?;
+
+    let attrs = &function.attrs;
+    let vis = &function.vis;
+    let name = &function.sig.ident;
+    let output = &function.sig.output;
+    let body = &function.block;
+
+    let test_attr = kind.attrs();
+    let fn_path = kind.fn_path();
+
+    Ok(quote! {
+        #test_attr
+        #(#attrs)*
+        #vis fn #name() #output {
+            #fn_path (async move {
+                #body
+            })
+        }
+    }.into())
+}
+
+pub fn async_test_attribute(args: TokenStream, input: TokenStream) -> TokenStream {
+    _async_entry(args, input, Kind::Test).unwrap_or_else(|d| { d.emit(); TokenStream::new() })
+}
+
+pub fn main_attribute(args: TokenStream, input: TokenStream) -> TokenStream {
+    _async_entry(args, input, Kind::Main).unwrap_or_else(|d| { d.emit(); TokenStream::new() })
+}

core/codegen/src/attribute/async_test.rs

@@ -1,43 +0,0 @@
-use proc_macro::{TokenStream, Span};
-use devise::{syn, Result};
-
-use crate::syn_ext::syn_to_diag;
-
-fn parse_input(input: TokenStream) -> Result<syn::ItemFn> {
-    let function: syn::ItemFn = syn::parse(input).map_err(syn_to_diag)
-        .map_err(|diag| diag.help("`#[async_test]` can only be applied to async functions"))?;
-
-    if function.sig.asyncness.is_none() {
-        return Err(Span::call_site().error("`#[async_test]` can only be applied to async functions"))
-    }
-
-    if !function.sig.inputs.is_empty() {
-        return Err(Span::call_site().error("`#[async_test]` can only be applied to functions with no parameters"));
-    }
-
-    Ok(function)
-}
-
-pub fn _async_test(_args: TokenStream, input: TokenStream) -> Result<TokenStream> {
-    let function = parse_input(input)?;
-
-    let attrs = &function.attrs;
-    let vis = &function.vis;
-    let name = &function.sig.ident;
-    let output = &function.sig.output;
-    let body = &function.block;
-
-    Ok(quote! {
-        #[test]
-        #(#attrs)*
-        #vis fn #name() #output {
-            rocket::async_test(async move {
-                #body
-            })
-        }
-    }.into())
-}
-
-pub fn async_test_attribute(args: TokenStream, input: TokenStream) -> TokenStream {
-    _async_test(args, input).unwrap_or_else(|d| { d.emit(); TokenStream::new() })
-}

core/codegen/src/attribute/mod.rs

@@ -1,4 +1,4 @@
-pub mod async_test;
+pub mod async_entry;
 pub mod catch;
 pub mod route;
 pub mod segments;

core/codegen/src/lib.rs

@@ -407,7 +407,12 @@ pub fn catch(args: TokenStream, input: TokenStream) -> TokenStream {
 
 #[proc_macro_attribute]
 pub fn async_test(args: TokenStream, input: TokenStream) -> TokenStream {
-    emit!(attribute::async_test::async_test_attribute(args, input))
+    emit!(attribute::async_entry::async_test_attribute(args, input))
+}
+
+#[proc_macro_attribute]
+pub fn main(args: TokenStream, input: TokenStream) -> TokenStream {
+    emit!(attribute::async_entry::main_attribute(args, input))
 }
 
 /// Derive for the [`FromFormValue`] trait.

core/lib/src/catcher.rs

@@ -52,9 +52,10 @@ use yansi::Color::*;
 ///     format!("I couldn't find '{}'. Try something else?", req.uri())
 /// }
 ///
-/// fn main() {
+/// #[rocket::main]
+/// async fn main() {
 /// # if false { // We don't actually want to launch the server in an example.
-///     rocket::ignite().register(catchers![internal_error, not_found]).launch();
+///     rocket::ignite().register(catchers![internal_error, not_found]).launch().await;
 /// # }
 /// }
 /// ```

core/lib/src/error.rs

@@ -65,8 +65,8 @@ pub enum LaunchErrorKind {
 /// ```rust
 /// use rocket::error::Error;
 ///
-/// # if false {
-/// if let Err(error) = rocket::ignite().launch() {
+/// # let _ = async {
+/// if let Err(error) = rocket::ignite().launch().await {
 ///     match error {
 ///         Error::Launch(error) => {
 ///             // This case is only reached if launching failed. This println "inspects" the error.
@@ -82,20 +82,20 @@ pub enum LaunchErrorKind {
 ///     }
 /// }
 ///
-/// # }
+/// # };
 /// ```
 ///
 /// When a value of this type panics, the corresponding error message is pretty
 /// printed to the console. The following illustrates this:
 ///
 /// ```rust
-/// # if false {
-/// let error = rocket::ignite().launch();
+/// # let _ = async {
+/// let error = rocket::ignite().launch().await;
 ///
 /// // This call to drop (explicit here for demonstration) will result in
 /// // `error` being pretty-printed to the console along with a `panic!`.
 /// drop(error);
-/// # }
+/// # };
 /// ```
 ///
 /// # Usage
@@ -136,14 +136,14 @@ impl LaunchError {
     ///
     /// ```rust
     /// use rocket::error::Error;
-    /// # if false {
-    /// if let Err(error) = rocket::ignite().launch() {
+    /// # let _ = async {
+    /// if let Err(error) = rocket::ignite().launch().await {
     ///     match error {
     ///         Error::Launch(err) => println!("Found a launch error: {}", err.kind()),
     ///         Error::Run(err) => println!("Error at runtime"),
     ///     }
     /// }
-    /// # }
+    /// # };
     /// ```
     #[inline]
     pub fn kind(&self) -> &LaunchErrorKind {

core/lib/src/handler.rs

@@ -65,11 +65,13 @@ pub type HandlerFuture<'r> = BoxFuture<'r, Outcome<'r>>;
 ///     }
 /// }
 ///
-/// fn main() {
+/// #[rocket::main]
+/// async fn main() {
 /// # if false {
 ///     rocket::ignite()
 ///         .mount("/", CustomHandler(Kind::Simple))
-///         .launch();
+///         .launch()
+///         .await;
 /// # }
 /// }
 /// ```
@@ -112,12 +114,14 @@ pub type HandlerFuture<'r> = BoxFuture<'r, Outcome<'r>>;
 ///     }
 /// }
 ///
-/// fn main() {
+/// #[rocket::main]
+/// async fn main() {
 /// # if false {
 ///     rocket::ignite()
 ///         .mount("/", routes![custom_handler])
 ///         .manage(Kind::Simple)
-///         .launch();
+///         .launch()
+///         .await;
 /// # }
 /// }
 /// ```

core/lib/src/lib.rs

@@ -67,9 +67,10 @@
 //!     "Hello, world!"
 //! }
 //!
-//! fn main() {
+//! #[rocket::main]
+//! async fn main() {
 //! # if false { // We don't actually want to launch the server in an example.
-//!     rocket::ignite().mount("/", routes![hello]).launch();
+//!     rocket::ignite().mount("/", routes![hello]).launch().await;
 //! # }
 //! }
 //! ```
@@ -164,3 +165,14 @@ pub fn async_test<R>(fut: impl std::future::Future<Output = R> + Send) -> R {
         .expect("create tokio runtime")
         .block_on(fut)
 }
+
+/// WARNING: This is unstable! Do not use this method outside of Rocket!
+#[doc(hidden)]
+pub fn async_main<R>(fut: impl std::future::Future<Output = R> + Send) -> R {
+    tokio::runtime::Builder::new()
+        .threaded_scheduler()
+        .enable_all()
+        .build()
+        .expect("create tokio runtime")
+        .block_on(fut)
+}

core/lib/src/request/state.rs

@@ -42,7 +42,8 @@ use crate::http::Status;
 ///     state.inner().user_val.as_str()
 /// }
 ///
-/// fn main() {
+/// #[rocket::main]
+/// async fn main() {
 ///     let config = MyConfig {
 ///         user_val: "user input".to_string()
 ///     };
@@ -51,7 +52,8 @@ use crate::http::Status;
 ///     rocket::ignite()
 ///         .mount("/", routes![index, raw_config_value])
 ///         .manage(config)
-///         .launch();
+///         .launch()
+///         .await;
 /// # }
 /// }
 /// ```

core/lib/src/response/flash.rs

@@ -69,9 +69,10 @@ const FLASH_COOKIE_DELIM: char = ':';
 ///          .unwrap_or_else(|| "Welcome!".to_string())
 /// }
 ///
-/// fn main() {
+/// #[rocket::main]
+/// async fn main() {
 /// # if false { // We don't actually want to launch the server in an example.
-///     rocket::ignite().mount("/", routes![login, index]).launch();
+///     rocket::ignite().mount("/", routes![login, index]).launch().await;
 /// # }
 /// }
 /// ```

core/lib/src/rocket.rs

@@ -656,10 +656,11 @@ impl Rocket {
     ///     "Hello!"
     /// }
     ///
-    /// fn main() {
+    /// #[rocket::main]
+    /// async fn main() {
     /// # if false { // We don't actually want to launch the server in an example.
     ///     rocket::ignite().mount("/hello", routes![hi])
-    /// #       .launch();
+    /// #       .launch().await;
     /// # }
     /// }
     /// ```
@@ -677,10 +678,10 @@ impl Rocket {
     ///     Outcome::from(req, "Hello!")
     /// }
     ///
-    /// # if false { // We don't actually want to launch the server in an example.
+    /// # let _ = async { // We don't actually want to launch the server in an example.
     /// rocket::ignite().mount("/hello", vec![Route::new(Get, "/world", hi)])
-    /// #     .launch();
-    /// # }
+    /// #     .launch().await;
+    /// # };
     /// ```
     #[inline]
     pub fn mount<R: Into<Vec<Route>>>(mut self, base: &str, routes: R) -> Self {
@@ -718,11 +719,12 @@ impl Rocket {
     ///     format!("I couldn't find '{}'. Try something else?", req.uri())
     /// }
     ///
-    /// fn main() {
+    /// #[rocket::main]
+    /// async fn main() {
     /// # if false { // We don't actually want to launch the server in an example.
     ///     rocket::ignite()
     ///         .register(catchers![internal_error, not_found])
-    /// #       .launch();
+    /// #       .launch().await;
     /// # }
     /// }
     /// ```
@@ -760,12 +762,14 @@ impl Rocket {
     ///     format!("The stateful value is: {}", state.0)
     /// }
     ///
-    /// fn main() {
+    /// #[rocket::main]
+    /// async fn main() {
     /// # if false { // We don't actually want to launch the server in an example.
     ///     rocket::ignite()
     ///         .mount("/", routes![index])
     ///         .manage(MyValue(10))
-    ///         .launch();
+    ///         .launch()
+    ///         .await;
     /// # }
     /// }
     /// ```
@@ -795,13 +799,15 @@ impl Rocket {
     /// use rocket::Rocket;
     /// use rocket::fairing::AdHoc;
     ///
-    /// fn main() {
+    /// #[rocket::main]
+    /// async fn main() {
     /// # if false { // We don't actually want to launch the server in an example.
     ///     rocket::ignite()
     ///         .attach(AdHoc::on_launch("Launch Message", |_| {
     ///             println!("Rocket is launching!");
     ///         }))
-    ///         .launch();
+    ///         .launch()
+    ///         .await;
     /// # }
     /// }
     /// ```
@@ -863,15 +869,15 @@ impl Rocket {
     /// # Example
     ///
     /// ```rust
-    /// #[tokio::main]
+    /// #[rocket::main]
     /// async fn main() {
     /// # if false {
-    ///     let result = rocket::ignite().launch();
+    ///     let result = rocket::ignite().launch().await;
     ///     assert!(result.is_ok());
     /// # }
     /// }
     /// ```
-    async fn serve(self) -> Result<(), crate::error::Error> {
+    pub async fn launch(self) -> Result<(), crate::error::Error> {
         use std::net::ToSocketAddrs;
 
         use crate::error::Error::Launch;
@@ -954,40 +960,6 @@ impl Rocket {
         server.await
     }
 
-    /// Starts the application server and begins listening for and dispatching
-    /// requests to mounted routes and catchers. This function does not return
-    /// unless a shutdown is requested via a [`ShutdownHandle`] or there is an
-    /// error.
-    ///
-    /// This is a convenience function that creates a suitable default runtime
-    /// and launches the server on that runtime. If you already have a runtime,
-    /// use the [`Rocket::serve`] method instead.
-    ///
-    /// # Error
-    ///
-    /// If there is a problem starting the application, a [`LaunchError`] is
-    /// returned. Note that a value of type `LaunchError` panics if dropped
-    /// without first being inspected. See the [`LaunchError`] documentation for
-    /// more information.
-    ///
-    /// # Example
-    ///
-    /// ```rust
-    /// # if false {
-    /// rocket::ignite().launch();
-    /// # }
-    /// ```
-    pub fn launch(self) -> Result<(), crate::error::Error> {
-        // Initialize the tokio runtime
-        let mut runtime = tokio::runtime::Builder::new()
-            .threaded_scheduler()
-            .enable_all()
-            .build()
-            .expect("Cannot build runtime!");
-
-        runtime.block_on(async move { self.serve().await })
-    }
-
     pub(crate) fn _manifest(&self) -> &Manifest {
         self.manifest.as_ref().expect("internal error: manifest was taken and not replaced. \
                                       Was `inspect()` called but not polled to completion?")
@@ -1079,7 +1051,7 @@ impl Manifest {
     /// });
     ///
     /// // Shuts down after 10 seconds
-    /// let shutdown_result = rocket.launch();
+    /// let shutdown_result = rocket.launch().await;
     /// assert!(shutdown_result.is_ok());
     /// # }
     /// # });
@@ -1160,13 +1132,15 @@ impl Manifest {
     /// use rocket::Rocket;
     /// use rocket::fairing::AdHoc;
     ///
-    /// fn main() {
+    /// #[rocket::main]
+    /// async fn main() {
     /// # if false { // We don't actually want to launch the server in an example.
     ///     rocket::ignite()
     ///         .attach(AdHoc::on_launch("Config Printer", |manifest| {
     ///             println!("Rocket launch config: {:?}", manifest.config());
     ///         }))
-    ///         .launch();
+    ///         .launch()
+    ///         .await;
     /// # }
     /// }
     /// ```

core/lib/src/shutdown.rs

@@ -24,11 +24,13 @@ use tokio::sync::mpsc;
 ///     "Shutting down..."
 /// }
 ///
-/// fn main() {
+/// #[rocket::main]
+/// async fn main() {
 ///     # if false {
 ///     rocket::ignite()
 ///         .mount("/", routes![shutdown])
 ///         .launch()
+///         .await
 ///         .expect("server failed unexpectedly");
 ///     # }
 /// }

examples/config/src/main.rs

@@ -1,4 +1,5 @@
 // This example's illustration is the Rocket.toml file.
-fn main() {
-    let _ = rocket::ignite().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket::ignite().launch().await;
 }

examples/content_types/src/main.rs

@@ -63,9 +63,10 @@ fn not_found(request: &Request<'_>) -> Html<String> {
     Html(html)
 }
 
-fn main() {
+#[rocket::main]
+async fn main() {
     let _ = rocket::ignite()
         .mount("/hello", routes![get_hello, post_hello])
         .register(catchers![not_found])
-        .launch();
+        .launch().await;
 }

examples/cookies/src/main.rs

@@ -38,6 +38,7 @@ fn rocket() -> rocket::Rocket {
     rocket::ignite().mount("/", routes![submit, index]).attach(Template::fairing())
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/errors/src/main.rs

@@ -18,12 +18,13 @@ fn not_found(req: &rocket::Request<'_>) -> content::Html<String> {
             req.uri()))
 }
 
-fn main() {
+#[rocket::main]
+async fn main() {
     let result = rocket::ignite()
         // .mount("/", routes![hello, hello]) // uncoment this to get an error
         .mount("/", routes![hello])
         .register(catchers![not_found])
-        .launch();
+        .launch().await;
 
     if let Err(e) = result {
         println!("Whoops! Rocket didn't launch!");

examples/fairings/src/main.rs

@@ -94,6 +94,7 @@ fn rocket() -> rocket::Rocket {
         }))
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/form_kitchen_sink/src/main.rs

@@ -45,6 +45,7 @@ fn rocket() -> rocket::Rocket {
     rocket::ignite().mount("/", routes![index, sink])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/form_validation/src/main.rs

@@ -81,6 +81,7 @@ fn rocket() -> rocket::Rocket {
         .mount("/", routes![files::index, files::files, user_page, login])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/handlebars_templates/src/main.rs

@@ -77,6 +77,7 @@ fn rocket() -> rocket::Rocket {
         }))
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/hello_2018/src/main.rs

@@ -9,6 +9,7 @@ fn hello() -> &'static str {
     "Hello, Rust 2018!"
 }
 
-fn main() {
-    let _ = rocket::ignite().mount("/", routes![hello]).launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket::ignite().mount("/", routes![hello]).launch().await;
 }

examples/hello_person/src/main.rs

@@ -14,6 +14,7 @@ fn hi(name: String) -> String {
     name
 }
 
-fn main() {
-    let _ = rocket::ignite().mount("/", routes![hello, hi]).launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket::ignite().mount("/", routes![hello, hi]).launch().await;
 }

examples/hello_world/src/main.rs

@@ -9,6 +9,7 @@ fn hello() -> &'static str {
     "Hello, world!"
 }
 
-fn main() {
-    let _ = rocket::ignite().mount("/", routes![hello]).launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket::ignite().mount("/", routes![hello]).launch().await;
 }

examples/json/src/main.rs

@@ -76,6 +76,7 @@ fn rocket() -> rocket::Rocket {
         .manage(Mutex::new(HashMap::<ID, String>::new()))
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/managed_queue/src/main.rs

@@ -25,6 +25,7 @@ fn rocket() -> rocket::Rocket {
         .manage(LogChannel(SegQueue::new()))
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/manual_routes/src/main.rs

@@ -118,6 +118,7 @@ fn rocket() -> rocket::Rocket {
         .register(vec![not_found_catcher])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/msgpack/src/main.rs

@@ -27,6 +27,7 @@ fn rocket() -> rocket::Rocket {
     rocket::ignite().mount("/message", routes![get, create])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/optional_redirect/src/main.rs

@@ -26,6 +26,7 @@ fn login() -> &'static str {
     "Hi! That user doesn't exist. Maybe you need to log in?"
 }
 
-fn main() {
-    let _ = rocket::ignite().mount("/", routes![root, user, login]).launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket::ignite().mount("/", routes![root, user, login]).launch().await;
 }

examples/pastebin/src/main.rs

@@ -55,6 +55,7 @@ fn rocket() -> rocket::Rocket {
     rocket::ignite().mount("/", routes![index, upload, retrieve])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/query_params/src/main.rs

@@ -36,6 +36,7 @@ fn rocket() -> rocket::Rocket {
     rocket::ignite().mount("/", routes![hello, hello_20])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/ranking/src/main.rs

@@ -16,6 +16,7 @@ fn hi(name: String, age: &RawStr) -> String {
     format!("Hi {}! Your age ({}) is kind of funky.", name, age)
 }
 
-fn main() {
-    let _ = rocket::ignite().mount("/", routes![hi, hello]).launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket::ignite().mount("/", routes![hi, hello]).launch().await;
 }

examples/raw_sqlite/src/main.rs

@@ -48,6 +48,7 @@ fn rocket() -> Rocket {
         .mount("/", routes![hello])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/raw_upload/src/main.rs

@@ -21,6 +21,7 @@ fn rocket() -> rocket::Rocket {
     rocket::ignite().mount("/", routes![index, upload])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/redirect/src/main.rs

@@ -16,6 +16,7 @@ fn login() -> &'static str {
     "Hi! Please log in before continuing."
 }
 
-fn main() {
-    let _ = rocket::ignite().mount("/", routes![root, login]).launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket::ignite().mount("/", routes![root, login]).launch().await;
 }

examples/request_guard/src/main.rs

@@ -26,8 +26,9 @@ fn rocket() -> rocket::Rocket {
     rocket::ignite().mount("/", routes![header_count])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }
 
 #[cfg(test)]

examples/request_local_state/src/main.rs

@@ -84,6 +84,7 @@ fn rocket() -> rocket::Rocket {
         .mount("/", routes![r_sync, r_async])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/session/src/main.rs

@@ -86,6 +86,7 @@ fn rocket() -> rocket::Rocket {
         .mount("/", routes![index, user_index, login, logout, login_user, login_page])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/state/src/main.rs

@@ -30,6 +30,7 @@ fn rocket() -> rocket::Rocket {
         .manage(HitCount(AtomicUsize::new(0)))
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/static_files/src/main.rs

@@ -9,6 +9,7 @@ fn rocket() -> rocket::Rocket {
     rocket::ignite().mount("/", StaticFiles::from("static"))
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/stream/src/main.rs

@@ -26,6 +26,7 @@ fn rocket() -> rocket::Rocket {
     rocket::ignite().mount("/", routes![root, file])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/tera_templates/src/main.rs

@@ -42,6 +42,7 @@ fn rocket() -> rocket::Rocket {
         .register(catchers![not_found])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/testing/src/main.rs

@@ -11,8 +11,9 @@ fn rocket() -> rocket::Rocket {
     rocket::ignite().mount("/", routes![hello])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }
 
 #[cfg(test)]

examples/tls/src/main.rs

@@ -9,6 +9,7 @@ fn hello() -> &'static str {
     "Hello, world!"
 }
 
-fn main() {
-    let _ = rocket::ignite().mount("/", routes![hello]).launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket::ignite().mount("/", routes![hello]).launch().await;
 }

examples/todo/src/main.rs

@@ -114,6 +114,7 @@ fn rocket() -> Rocket {
         .attach(Template::fairing())
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

examples/uuid/src/main.rs

@@ -37,6 +37,7 @@ fn rocket() -> rocket::Rocket {
     rocket::ignite().mount("/", routes![people])
 }
 
-fn main() {
-    let _ = rocket().launch();
+#[rocket::main]
+async fn main() {
+    let _ = rocket().launch().await;
 }

site/guide/3-overview.md

@@ -238,9 +238,9 @@ You can find async-ready libraries on [crates.io](https://crates.io) with the
 
 ! note
 
-  Rocket 0.5 uses the tokio (0.2) runtime. `Rocket::launch()` will automatically
-  start a runtime for you, or you can create a runtime yourself and use
-  `Rocket::spawn()`.
+  Rocket 0.5 uses the tokio (0.2) runtime. The runtime is started for you
+  if you use `#[rocket::main]`, but you can still `launch()` a rocket
+  instance on a custom-built `Runtime`.
 
 ### Cooperative Multitasking