reorganize library/std/src/sync/mod.rs file

Moves things around to make a bit more sense (plus prepare moving `once`
out of `poison`.

Signed-off-by: Connor Tsui <[email protected]>

Author: connortsui20

library/std/src/sync/mod.rs

@@ -181,7 +181,20 @@ pub use alloc_crate::sync::UniqueArc;
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use alloc_crate::sync::{Arc, Weak};
 
-// FIXME(sync_nonpoison,sync_poison_mod): remove all `#[doc(inline)]` once the modules are stabilized.
+#[unstable(feature = "mpmc_channel", issue = "126840")]
+pub mod mpmc;
+pub mod mpsc;
+
+// TODO: Make this `self::once::ONCE_INIT`.
+#[stable(feature = "rust1", since = "1.0.0")]
+#[doc(inline)]
+#[expect(deprecated)]
+pub use self::poison::ONCE_INIT;
+
+mod barrier;
+mod lazy_lock;
+mod once_lock;
+mod reentrant_lock;
 
 // These exist only in one flavor: no poisoning.
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -193,49 +206,38 @@ pub use self::once_lock::OnceLock;
 #[unstable(feature = "reentrant_lock", issue = "121440")]
 pub use self::reentrant_lock::{ReentrantLock, ReentrantLockGuard};
 
-// These make sense and exist only with poisoning.
+// Note: in the future we will change the default version in `std::sync` to the non-poisoning
+// version over an edition.
+// See https://github.com/rust-lang/rust/issues/134645#issuecomment-3324577500 for more details.
+
+#[unstable(feature = "sync_nonpoison", issue = "134645")]
+pub mod nonpoison;
+#[unstable(feature = "sync_poison_mod", issue = "134646")]
+pub mod poison;
+
+// FIXME(sync_poison_mod): remove all `#[doc(inline)]` once the modules are stabilized.
+
+// These exist only with poisoning.
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(inline)]
 pub use self::poison::{LockResult, PoisonError};
 
-// These (should) exist in both flavors: with and without poisoning.
-// FIXME(sync_nonpoison): implement nonpoison versions:
-//  * Mutex (nonpoison_mutex)
-//  * Condvar (nonpoison_condvar)
-//  * Once (nonpoison_once)
-//  * RwLock (nonpoison_rwlock)
+// These exist in both flavors: with and without poisoning.
 // The historical default is the version with poisoning.
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(inline)]
 pub use self::poison::{
     TryLockError, TryLockResult,
-    Condvar,
     Mutex, MutexGuard,
     RwLock, RwLockReadGuard, RwLockWriteGuard,
+    Condvar,
     Once, OnceState,
 };
-#[stable(feature = "rust1", since = "1.0.0")]
-#[doc(inline)]
-#[expect(deprecated)]
-pub use self::poison::ONCE_INIT;
+
 #[unstable(feature = "mapped_lock_guards", issue = "117108")]
 #[doc(inline)]
 pub use self::poison::{MappedMutexGuard, MappedRwLockReadGuard, MappedRwLockWriteGuard};
 
-#[unstable(feature = "mpmc_channel", issue = "126840")]
-pub mod mpmc;
-pub mod mpsc;
-
-#[unstable(feature = "sync_nonpoison", issue = "134645")]
-pub mod nonpoison;
-#[unstable(feature = "sync_poison_mod", issue = "134646")]
-pub mod poison;
-
-mod barrier;
-mod lazy_lock;
-mod once_lock;
-mod reentrant_lock;
-
 /// A type indicating whether a timed wait on a condition variable returned
 /// due to a time out or not.
 ///