task: stabilise JoinMap (#7075)

tokio-util/Cargo.toml

@@ -21,7 +21,7 @@ categories = ["asynchronous"]
 default = []
 
 # Shorthand for enabling everything
-full = ["codec", "compat", "io-util", "time", "net", "rt"]
+full = ["codec", "compat", "io-util", "time", "net", "rt", "join-map"]
 
 net = ["tokio/net"]
 compat = ["futures-io"]
@@ -29,7 +29,8 @@ codec = []
 time = ["tokio/time", "slab"]
 io = []
 io-util = ["io", "tokio/rt", "tokio/io-util"]
-rt = ["tokio/rt", "tokio/sync", "futures-util", "hashbrown"]
+rt = ["tokio/rt", "tokio/sync", "futures-util"]
+join-map = ["rt", "hashbrown"]
 
 __docs_rs = ["futures-util"]
 
@@ -43,8 +44,6 @@ futures-util = { version = "0.3.0", optional = true }
 pin-project-lite = "0.2.11"
 slab = { version = "0.4.4", optional = true } # Backs `DelayQueue`
 tracing = { version = "0.1.29", default-features = false, features = ["std"], optional = true }
-
-[target.'cfg(tokio_unstable)'.dependencies]
 hashbrown = { version = "0.15.0", default-features = false, optional = true }
 
 [dev-dependencies]

tokio-util/src/lib.rs

@@ -45,9 +45,11 @@ cfg_io! {
 
 cfg_rt! {
     pub mod context;
-    pub mod task;
 }
 
+#[cfg(feature = "rt")]
+pub mod task;
+
 cfg_time! {
     pub mod time;
 }

tokio-util/src/task/join_map.rs

@@ -29,10 +29,6 @@ use tokio::task::{AbortHandle, Id, JoinError, JoinSet, LocalSet};
 ///
 /// When the `JoinMap` is dropped, all tasks in the `JoinMap` are immediately aborted.
 ///
-/// **Note**: This type depends on Tokio's [unstable API][unstable]. See [the
-/// documentation on unstable features][unstable] for details on how to enable
-/// Tokio's unstable features.
-///
 /// # Examples
 ///
 /// Spawn multiple tasks and wait for them:
@@ -96,11 +92,9 @@ use tokio::task::{AbortHandle, Id, JoinError, JoinSet, LocalSet};
 /// ```
 ///
 /// [`JoinSet`]: tokio::task::JoinSet
-/// [unstable]: tokio#unstable-features
 /// [abort]: fn@Self::abort
 /// [abort_matching]: fn@Self::abort_matching
 /// [contains]: fn@Self::contains_key
-#[cfg_attr(docsrs, doc(cfg(all(feature = "rt", tokio_unstable))))]
 pub struct JoinMap<K, V, S = RandomState> {
     /// A map of the [`AbortHandle`]s of the tasks spawned on this `JoinMap`,
     /// indexed by their keys.
@@ -541,9 +535,9 @@ where
     /// assert!(!map.abort("goodbye universe"));
     /// # }
     /// ```
-    pub fn abort<Q: ?Sized>(&mut self, key: &Q) -> bool
+    pub fn abort<Q>(&mut self, key: &Q) -> bool
     where
-        Q: Hash + Eq,
+        Q: ?Sized + Hash + Eq,
         K: Borrow<Q>,
     {
         match self.get_by_key(key) {
@@ -638,9 +632,9 @@ where
     /// call to [`join_next`], this method will still return `true`.
     ///
     /// [`join_next`]: fn@Self::join_next
-    pub fn contains_key<Q: ?Sized>(&self, key: &Q) -> bool
+    pub fn contains_key<Q>(&self, key: &Q) -> bool
     where
-        Q: Hash + Eq,
+        Q: ?Sized + Hash + Eq,
         K: Borrow<Q>,
     {
         self.get_by_key(key).is_some()
@@ -744,9 +738,9 @@ where
     }
 
     /// Look up a task in the map by its key, returning the key and abort handle.
-    fn get_by_key<'map, Q: ?Sized>(&'map self, key: &Q) -> Option<&'map (K, AbortHandle)>
+    fn get_by_key<'map, Q>(&'map self, key: &Q) -> Option<&'map (K, AbortHandle)>
     where
-        Q: Hash + Eq,
+        Q: ?Sized + Hash + Eq,
         K: Borrow<Q>,
     {
         let hash_builder = self.hashes_by_task.hasher();
@@ -774,9 +768,10 @@ where
 
 /// Returns the hash for a given key.
 #[inline]
-fn hash_one<S: BuildHasher, Q: ?Sized>(hash_builder: &S, key: &Q) -> u64
+fn hash_one<S, Q>(hash_builder: &S, key: &Q) -> u64
 where
-    Q: Hash,
+    Q: ?Sized + Hash,
+    S: BuildHasher,
 {
     let mut hasher = hash_builder.build_hasher();
     key.hash(&mut hasher);

tokio-util/src/task/mod.rs

@@ -1,16 +1,21 @@
 //! Extra utilities for spawning tasks
+//!
+//! This module is only available when the `rt` feature is enabled. Note that enabling the
+//! `join-map` feature will automatically also enable the `rt` feature.
 
-#[cfg(tokio_unstable)]
+cfg_rt! {
+    mod spawn_pinned;
+    pub use spawn_pinned::LocalPoolHandle;
+
+    pub mod task_tracker;
+    pub use task_tracker::TaskTracker;
+
+    mod abort_on_drop;
+    pub use abort_on_drop::AbortOnDropHandle;
+}
+
+#[cfg(feature = "join-map")]
 mod join_map;
-mod spawn_pinned;
+#[cfg(feature = "join-map")]
-pub use spawn_pinned::LocalPoolHandle;
+#[cfg_attr(docsrs, doc(cfg(feature = "join-map")))]
-
-#[cfg(tokio_unstable)]
-#[cfg_attr(docsrs, doc(cfg(all(tokio_unstable, feature = "rt"))))]
 pub use join_map::{JoinMap, JoinMapKeys};
-
-pub mod task_tracker;
-pub use task_tracker::TaskTracker;
-
-mod abort_on_drop;
-pub use abort_on_drop::AbortOnDropHandle;

tokio-util/tests/task_join_map.rs

@@ -1,5 +1,5 @@
 #![warn(rust_2018_idioms)]
-#![cfg(all(feature = "rt", tokio_unstable))]
+#![cfg(feature = "join-map")]
 
 use std::panic::AssertUnwindSafe;
 
@@ -26,7 +26,7 @@ async fn test_with_sleep() {
     map.detach_all();
     assert_eq!(map.len(), 0);
 
-    assert!(matches!(map.join_next().await, None));
+    assert!(map.join_next().await.is_none());
 
     for i in 0..10 {
         map.spawn(i, async move {
@@ -45,7 +45,7 @@ async fn test_with_sleep() {
     for was_seen in &seen {
         assert!(was_seen);
     }
-    assert!(matches!(map.join_next().await, None));
+    assert!(map.join_next().await.is_none());
 
     // Do it again.
     for i in 0..10 {
@@ -64,7 +64,7 @@ async fn test_with_sleep() {
     for was_seen in &seen {
         assert!(was_seen);
     }
-    assert!(matches!(map.join_next().await, None));
+    assert!(map.join_next().await.is_none());
 }
 
 #[tokio::test]
@@ -250,7 +250,7 @@ async fn join_map_coop() {
     loop {
         match map.join_next().now_or_never() {
             Some(Some((key, Ok(i)))) => assert_eq!(key, i),
-            Some(Some((key, Err(err)))) => panic!("failed[{}]: {}", key, err),
+            Some(Some((key, Err(err)))) => panic!("failed[{key}]: {err}"),
             None => {
                 coop_count += 1;
                 tokio::task::yield_now().await;