runtime: stabilize LocalRuntime (#7557)

Daksh14 · web-flow · commit 1fc450aefba4 · 2026-04-02T13:13:24.000Z
diff --git a/tokio-macros/src/entry.rs b/tokio-macros/src/entry.rs
@@ -476,12 +476,7 @@ fn parse_knobs(mut input: ItemFn, is_test: bool, config: FinalConfig) -> TokenSt
         },
     };
 
-    let mut checks = vec![];
-    let mut errors = vec![];
-
     let build = if let RuntimeFlavor::Local = config.flavor {
-        checks.push(quote! { tokio_unstable });
-        errors.push("The local runtime flavor is only available when `tokio_unstable` is set.");
         quote_spanned! {last_stmt_start_span=> build_local(Default::default())}
     } else {
         quote_spanned! {last_stmt_start_span=> build()}
@@ -509,23 +504,10 @@ fn parse_knobs(mut input: ItemFn, is_test: bool, config: FinalConfig) -> TokenSt
         quote! {}
     };
 
-    let do_checks: TokenStream = checks
-        .iter()
-        .zip(&errors)
-        .map(|(check, error)| {
-            quote! {
-                #[cfg(not(#check))]
-                compile_error!(#error);
-            }
-        })
-        .collect();
-
     let body_ident = quote! { body };
     // This explicit `return` is intentional. See tokio-rs/tokio#4636
     let last_block = quote_spanned! {last_stmt_end_span=>
-        #do_checks
 
-        #[cfg(all(#(#checks),*))]
         #[allow(clippy::expect_used, clippy::diverging_sub_expression, clippy::needless_return, clippy::unwrap_in_result)]
         {
             #use_builder
@@ -537,10 +519,6 @@ fn parse_knobs(mut input: ItemFn, is_test: bool, config: FinalConfig) -> TokenSt
                 .block_on(#body_ident);
         }
 
-        #[cfg(not(all(#(#checks),*)))]
-        {
-            panic!("fell through checks")
-        }
     };
 
     let body = input.body();
diff --git a/tokio-macros/src/lib.rs b/tokio-macros/src/lib.rs
@@ -73,16 +73,11 @@ use proc_macro::TokenStream;
 ///
 /// ## Local
 ///
-/// [Unstable API][unstable] only.
-///
 /// To use the [local runtime], the macro can be configured using
 ///
 /// ```rust
-/// # #[cfg(tokio_unstable)]
 /// #[tokio::main(flavor = "local")]
 /// # async fn main() {}
-/// # #[cfg(not(tokio_unstable))]
-/// # fn main() {}
 /// ```
 ///
 /// # Function arguments
@@ -165,25 +160,19 @@ use proc_macro::TokenStream;
 ///
 /// ## Using the local runtime
 ///
-/// Available in the [unstable API][unstable] only.
-///
 /// The [local runtime] is similar to the current-thread runtime but
 /// supports [`task::spawn_local`](../tokio/task/fn.spawn_local.html).
 ///
 /// ```rust
-/// # #[cfg(tokio_unstable)]
 /// #[tokio::main(flavor = "local")]
 /// async fn main() {
 ///     println!("Hello world");
 /// }
-/// # #[cfg(not(tokio_unstable))]
-/// # fn main() {}
 /// ```
 ///
 /// Equivalent code not using `#[tokio::main]`
 ///
 /// ```rust
-/// # #[cfg(tokio_unstable)]
 /// fn main() {
 ///     tokio::runtime::Builder::new_current_thread()
 ///         .enable_all()
@@ -193,8 +182,6 @@ use proc_macro::TokenStream;
 ///             println!("Hello world");
 ///         })
 /// }
-/// # #[cfg(not(tokio_unstable))]
-/// # fn main() {}
 /// ```
 ///
 ///
diff --git a/tokio/src/runtime/builder.rs b/tokio/src/runtime/builder.rs
@@ -5,7 +5,9 @@ use crate::runtime::{
     blocking, driver, Callback, HistogramBuilder, Runtime, TaskCallback, TimerFlavor,
 };
 #[cfg(tokio_unstable)]
-use crate::runtime::{metrics::HistogramConfiguration, LocalOptions, LocalRuntime, TaskMeta};
+use crate::runtime::{metrics::HistogramConfiguration, TaskMeta};
+
+use crate::runtime::{LocalOptions, LocalRuntime};
 use crate::util::rand::{RngSeed, RngSeedGenerator};
 
 use crate::runtime::blocking::BlockingPool;
@@ -241,7 +243,7 @@ impl Builder {
     /// Configuration methods can be chained on the return value.
     ///
     /// To spawn non-`Send` tasks on the resulting runtime, combine it with a
-    /// [`LocalSet`], or call [`build_local`] to create a [`LocalRuntime`] (unstable).
+    /// [`LocalSet`], or call [`build_local`] to create a [`LocalRuntime`].
     ///
     /// [`LocalSet`]: crate::task::LocalSet
     /// [`LocalRuntime`]: crate::runtime::LocalRuntime
@@ -1048,8 +1050,6 @@ impl Builder {
     /// });
     /// ```
     #[allow(unused_variables, unreachable_patterns)]
-    #[cfg(tokio_unstable)]
-    #[cfg_attr(docsrs, doc(cfg(tokio_unstable)))]
     pub fn build_local(&mut self, options: LocalOptions) -> io::Result<LocalRuntime> {
         match &self.kind {
             Kind::CurrentThread => self.build_current_thread_local_runtime(),
@@ -1605,7 +1605,6 @@ impl Builder {
         ))
     }
 
-    #[cfg(tokio_unstable)]
     fn build_current_thread_local_runtime(&mut self) -> io::Result<LocalRuntime> {
         use crate::runtime::local_runtime::LocalRuntimeScheduler;
 
diff --git a/tokio/src/runtime/local_runtime/runtime.rs b/tokio/src/runtime/local_runtime/runtime.rs
@@ -29,7 +29,6 @@ use std::time::Duration;
 /// [runtime]: crate::runtime::Runtime
 /// [module]: crate::runtime
 #[derive(Debug)]
-#[cfg_attr(docsrs, doc(cfg(tokio_unstable)))]
 pub struct LocalRuntime {
     /// Task scheduler
     scheduler: LocalRuntimeScheduler,
diff --git a/tokio/src/runtime/mod.rs b/tokio/src/runtime/mod.rs
@@ -36,9 +36,9 @@
 //!                            | Yes                 | No
 //!                            |                     |
 //!                            V                     |
-//!              +--------------------------+        |
-//!              | Local Runtime (unstable) |        |
-//!              +--------------------------+        |
+//!                    +---------------+             |
+//!                    | Local Runtime |             |
+//!                    +---------------+             |
 //!                                                  |
 //!                                                  v
 //!                                      +------------------------+
@@ -575,9 +575,6 @@ cfg_rt! {
         pub use self::builder::UnhandledPanic;
         pub use crate::util::rand::RngSeed;
 
-        mod local_runtime;
-        pub use local_runtime::{LocalRuntime, LocalOptions};
-
         /// Returns the index of the current worker thread, if called from a
         /// runtime worker thread.
         ///
@@ -635,6 +632,9 @@ cfg_rt! {
     mod runtime;
     pub use runtime::{Runtime, RuntimeFlavor, is_rt_shutdown_err};
 
+    mod local_runtime;
+    pub use local_runtime::{LocalRuntime, LocalOptions};
+
     mod id;
     pub use id::Id;
 
diff --git a/tokio/src/task/local.rs b/tokio/src/task/local.rs
@@ -328,9 +328,8 @@ impl<'a> Drop for LocalDataEnterGuard<'a> {
 cfg_rt! {
     /// Spawns a `!Send` future on the current [`LocalSet`] or [`LocalRuntime`].
     ///
-    /// This is possible when either using one of these types
-    /// explicitly, or (with `tokio_unstable`) by opting to use the
-    /// `"local"` runtime flavor in `tokio::main`:
+    /// This is possible when either using one of these types explicitly, or by
+    /// opting to use the `"local"` runtime flavor in `tokio::main`:
     ///
     /// ```ignore
     /// #[tokio::main(flavor = "local")]
@@ -374,10 +373,9 @@ cfg_rt! {
     /// }).await;
     /// # }
     /// ```
-    /// With local runtime flavor ([Unstable API][unstable] only).
+    /// With local runtime flavor.
     ///
     /// ```rust
-    /// # #[cfg(tokio_unstable)]
     /// #[tokio::main(flavor = "local")]
     /// async fn main() {
     ///     let join = tokio::task::spawn_local(async {
@@ -386,8 +384,6 @@ cfg_rt! {
     ///
     ///    join.await.unwrap()
     ///  }
-    /// # #[cfg(not(tokio_unstable))]
-    /// # fn main() {}
     ///
     /// ```
     ///
