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-rw-r--r--library/std/src/env.rs7
-rw-r--r--library/std/src/io/error.rs18
-rw-r--r--library/std/src/io/error/repr_bitpacked.rs2
-rw-r--r--library/std/src/keyword_docs.rs122
-rw-r--r--library/std/src/lib.rs8
-rw-r--r--library/std/src/os/fd/owned.rs8
-rw-r--r--library/std/src/os/fd/raw.rs8
-rw-r--r--library/std/src/os/hurd/mod.rs1
-rw-r--r--library/std/src/os/windows/io/handle.rs8
-rw-r--r--library/std/src/os/windows/io/socket.rs8
-rw-r--r--library/std/src/panicking.rs2
-rw-r--r--library/std/src/path.rs4
-rw-r--r--library/std/src/pipe.rs140
-rw-r--r--library/std/src/prelude/common.rs3
-rw-r--r--library/std/src/prelude/mod.rs21
-rw-r--r--library/std/src/sync/mutex.rs110
-rw-r--r--library/std/src/sync/mutex/tests.rs161
-rw-r--r--library/std/src/sync/poison.rs35
-rw-r--r--library/std/src/sync/rwlock.rs128
-rw-r--r--library/std/src/sync/rwlock/tests.rs169
-rw-r--r--library/std/src/sys/backtrace.rs26
-rw-r--r--library/std/src/sys/pal/hermit/fs.rs6
-rw-r--r--library/std/src/sys/pal/hermit/mod.rs2
-rw-r--r--library/std/src/sys/pal/hermit/os.rs4
-rw-r--r--library/std/src/sys/pal/teeos/mod.rs2
-rw-r--r--library/std/src/sys/pal/unix/mod.rs2
-rw-r--r--library/std/src/sys/pal/unix/net.rs1
-rw-r--r--library/std/src/sys/pal/wasi/fs.rs175
-rw-r--r--library/std/src/sys/pal/windows/mod.rs4
-rw-r--r--library/std/src/sys/thread_local/key/unix.rs20
-rw-r--r--library/std/src/sys/thread_local/mod.rs5
-rw-r--r--library/std/src/thread/local.rs2
32 files changed, 943 insertions, 269 deletions
diff --git a/library/std/src/env.rs b/library/std/src/env.rs
index 043747d0bc5..535236ff89a 100644
--- a/library/std/src/env.rs
+++ b/library/std/src/env.rs
@@ -597,6 +597,13 @@ impl Error for JoinPathsError {
 
 /// Returns the path of the current user's home directory if known.
 ///
+/// This may return `None` if getting the directory fails or if the platform does not have user home directories.
+///
+/// For storing user data and configuration it is often preferable to use more specific directories.
+/// For example, [XDG Base Directories] on Unix or the `LOCALAPPDATA` and `APPDATA` environment variables on Windows.
+///
+/// [XDG Base Directories]: https://specifications.freedesktop.org/basedir-spec/latest/
+///
 /// # Unix
 ///
 /// - Returns the value of the 'HOME' environment variable if it is set
diff --git a/library/std/src/io/error.rs b/library/std/src/io/error.rs
index 03f38e220a5..476c403c21f 100644
--- a/library/std/src/io/error.rs
+++ b/library/std/src/io/error.rs
@@ -338,9 +338,9 @@ pub enum ErrorKind {
     /// example, on Unix, a named pipe opened with `File::open`.
     #[stable(feature = "io_error_a_bit_more", since = "1.83.0")]
     NotSeekable,
-    /// Filesystem quota was exceeded.
-    #[unstable(feature = "io_error_more", issue = "86442")]
-    FilesystemQuotaExceeded,
+    /// Filesystem quota or some other kind of quota was exceeded.
+    #[stable(feature = "io_error_quota_exceeded", since = "CURRENT_RUSTC_VERSION")]
+    QuotaExceeded,
     /// File larger than allowed or supported.
     ///
     /// This might arise from a hard limit of the underlying filesystem or file access API, or from
@@ -364,7 +364,7 @@ pub enum ErrorKind {
     #[stable(feature = "io_error_a_bit_more", since = "1.83.0")]
     Deadlock,
     /// Cross-device or cross-filesystem (hard) link or rename.
-    #[unstable(feature = "io_error_more", issue = "86442")]
+    #[stable(feature = "io_error_crosses_devices", since = "CURRENT_RUSTC_VERSION")]
     CrossesDevices,
     /// Too many (hard) links to the same filesystem object.
     ///
@@ -446,8 +446,8 @@ pub enum ErrorKind {
 impl ErrorKind {
     pub(crate) fn as_str(&self) -> &'static str {
         use ErrorKind::*;
-        // tidy-alphabetical-start
         match *self {
+            // tidy-alphabetical-start
             AddrInUse => "address in use",
             AddrNotAvailable => "address not available",
             AlreadyExists => "entity already exists",
@@ -460,12 +460,11 @@ impl ErrorKind {
             Deadlock => "deadlock",
             DirectoryNotEmpty => "directory not empty",
             ExecutableFileBusy => "executable file busy",
-            FileTooLarge => "file too large",
             FilesystemLoop => "filesystem loop or indirection limit (e.g. symlink loop)",
-            FilesystemQuotaExceeded => "filesystem quota exceeded",
+            FileTooLarge => "file too large",
             HostUnreachable => "host unreachable",
-            Interrupted => "operation interrupted",
             InProgress => "in progress",
+            Interrupted => "operation interrupted",
             InvalidData => "invalid data",
             InvalidFilename => "invalid filename",
             InvalidInput => "invalid input parameter",
@@ -479,6 +478,7 @@ impl ErrorKind {
             Other => "other error",
             OutOfMemory => "out of memory",
             PermissionDenied => "permission denied",
+            QuotaExceeded => "quota exceeded",
             ReadOnlyFilesystem => "read-only filesystem or storage medium",
             ResourceBusy => "resource busy",
             StaleNetworkFileHandle => "stale network file handle",
@@ -490,8 +490,8 @@ impl ErrorKind {
             Unsupported => "unsupported",
             WouldBlock => "operation would block",
             WriteZero => "write zero",
+            // tidy-alphabetical-end
         }
-        // tidy-alphabetical-end
     }
 }
 
diff --git a/library/std/src/io/error/repr_bitpacked.rs b/library/std/src/io/error/repr_bitpacked.rs
index a839a2fbac1..f958a938646 100644
--- a/library/std/src/io/error/repr_bitpacked.rs
+++ b/library/std/src/io/error/repr_bitpacked.rs
@@ -335,7 +335,7 @@ fn kind_from_prim(ek: u32) -> Option<ErrorKind> {
         WriteZero,
         StorageFull,
         NotSeekable,
-        FilesystemQuotaExceeded,
+        QuotaExceeded,
         FileTooLarge,
         ResourceBusy,
         ExecutableFileBusy,
diff --git a/library/std/src/keyword_docs.rs b/library/std/src/keyword_docs.rs
index 4302e24781e..0c526eafdf3 100644
--- a/library/std/src/keyword_docs.rs
+++ b/library/std/src/keyword_docs.rs
@@ -807,64 +807,6 @@ mod in_keyword {}
 /// [Reference]: ../reference/statements.html#let-statements
 mod let_keyword {}
 
-#[doc(keyword = "while")]
-//
-/// Loop while a condition is upheld.
-///
-/// A `while` expression is used for predicate loops. The `while` expression runs the conditional
-/// expression before running the loop body, then runs the loop body if the conditional
-/// expression evaluates to `true`, or exits the loop otherwise.
-///
-/// ```rust
-/// let mut counter = 0;
-///
-/// while counter < 10 {
-///     println!("{counter}");
-///     counter += 1;
-/// }
-/// ```
-///
-/// Like the [`for`] expression, we can use `break` and `continue`. A `while` expression
-/// cannot break with a value and always evaluates to `()` unlike [`loop`].
-///
-/// ```rust
-/// let mut i = 1;
-///
-/// while i < 100 {
-///     i *= 2;
-///     if i == 64 {
-///         break; // Exit when `i` is 64.
-///     }
-/// }
-/// ```
-///
-/// As `if` expressions have their pattern matching variant in `if let`, so too do `while`
-/// expressions with `while let`. The `while let` expression matches the pattern against the
-/// expression, then runs the loop body if pattern matching succeeds, or exits the loop otherwise.
-/// We can use `break` and `continue` in `while let` expressions just like in `while`.
-///
-/// ```rust
-/// let mut counter = Some(0);
-///
-/// while let Some(i) = counter {
-///     if i == 10 {
-///         counter = None;
-///     } else {
-///         println!("{i}");
-///         counter = Some (i + 1);
-///     }
-/// }
-/// ```
-///
-/// For more information on `while` and loops in general, see the [reference].
-///
-/// See also, [`for`], [`loop`].
-///
-/// [`for`]: keyword.for.html
-/// [`loop`]: keyword.loop.html
-/// [reference]: ../reference/expressions/loop-expr.html#predicate-loops
-mod while_keyword {}
-
 #[doc(keyword = "loop")]
 //
 /// Loop indefinitely.
@@ -1321,10 +1263,10 @@ mod return_keyword {}
 /// [Reference]: ../reference/items/associated-items.html#methods
 mod self_keyword {}
 
-// FIXME: Once rustdoc can handle URL conflicts on case insensitive file systems, we can remove the
-// three next lines and put back: `#[doc(keyword = "Self")]`.
+// FIXME: Once rustdoc can handle URL conflicts on case insensitive file systems, we can replace
+// these two lines with `#[doc(keyword = "Self")]` and update `is_doc_keyword` in
+// `CheckAttrVisitor`.
 #[doc(alias = "Self")]
-#[allow(rustc::existing_doc_keyword)]
 #[doc(keyword = "SelfTy")]
 //
 /// The implementing type within a [`trait`] or [`impl`] block, or the current type within a type
@@ -2343,6 +2285,64 @@ mod use_keyword {}
 /// [RFC]: https://github.com/rust-lang/rfcs/blob/master/text/0135-where.md
 mod where_keyword {}
 
+#[doc(keyword = "while")]
+//
+/// Loop while a condition is upheld.
+///
+/// A `while` expression is used for predicate loops. The `while` expression runs the conditional
+/// expression before running the loop body, then runs the loop body if the conditional
+/// expression evaluates to `true`, or exits the loop otherwise.
+///
+/// ```rust
+/// let mut counter = 0;
+///
+/// while counter < 10 {
+///     println!("{counter}");
+///     counter += 1;
+/// }
+/// ```
+///
+/// Like the [`for`] expression, we can use `break` and `continue`. A `while` expression
+/// cannot break with a value and always evaluates to `()` unlike [`loop`].
+///
+/// ```rust
+/// let mut i = 1;
+///
+/// while i < 100 {
+///     i *= 2;
+///     if i == 64 {
+///         break; // Exit when `i` is 64.
+///     }
+/// }
+/// ```
+///
+/// As `if` expressions have their pattern matching variant in `if let`, so too do `while`
+/// expressions with `while let`. The `while let` expression matches the pattern against the
+/// expression, then runs the loop body if pattern matching succeeds, or exits the loop otherwise.
+/// We can use `break` and `continue` in `while let` expressions just like in `while`.
+///
+/// ```rust
+/// let mut counter = Some(0);
+///
+/// while let Some(i) = counter {
+///     if i == 10 {
+///         counter = None;
+///     } else {
+///         println!("{i}");
+///         counter = Some (i + 1);
+///     }
+/// }
+/// ```
+///
+/// For more information on `while` and loops in general, see the [reference].
+///
+/// See also, [`for`], [`loop`].
+///
+/// [`for`]: keyword.for.html
+/// [`loop`]: keyword.loop.html
+/// [reference]: ../reference/expressions/loop-expr.html#predicate-loops
+mod while_keyword {}
+
 // 2018 Edition keywords
 
 #[doc(alias = "promise")]
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 585946c1d50..1c80694ca8f 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -251,7 +251,6 @@
 #![allow(explicit_outlives_requirements)]
 #![allow(unused_lifetimes)]
 #![allow(internal_features)]
-#![deny(rustc::existing_doc_keyword)]
 #![deny(fuzzy_provenance_casts)]
 #![deny(unsafe_op_in_unsafe_fn)]
 #![allow(rustdoc::redundant_explicit_links)]
@@ -292,6 +291,7 @@
 #![feature(dropck_eyepatch)]
 #![feature(f128)]
 #![feature(f16)]
+#![feature(formatting_options)]
 #![feature(if_let_guard)]
 #![feature(intra_doc_pointers)]
 #![feature(lang_items)]
@@ -347,7 +347,6 @@
 #![feature(pin_coerce_unsized_trait)]
 #![feature(pointer_is_aligned_to)]
 #![feature(portable_simd)]
-#![feature(prelude_2024)]
 #![feature(ptr_as_uninit)]
 #![feature(ptr_mask)]
 #![feature(random)]
@@ -373,6 +372,7 @@
 #![feature(thin_box)]
 #![feature(try_reserve_kind)]
 #![feature(try_with_capacity)]
+#![feature(unique_rc_arc)]
 #![feature(vec_into_raw_parts)]
 // tidy-alphabetical-end
 //
@@ -544,6 +544,8 @@ pub use core::u64;
 #[stable(feature = "i128", since = "1.26.0")]
 #[allow(deprecated, deprecated_in_future)]
 pub use core::u128;
+#[unstable(feature = "unsafe_binders", issue = "130516")]
+pub use core::unsafe_binder;
 #[stable(feature = "rust1", since = "1.0.0")]
 #[allow(deprecated, deprecated_in_future)]
 pub use core::usize;
@@ -589,7 +591,7 @@ pub mod net;
 pub mod num;
 pub mod os;
 pub mod panic;
-#[unstable(feature = "core_pattern_types", issue = "123646")]
+#[unstable(feature = "pattern_type_macro", issue = "123646")]
 pub mod pat;
 pub mod path;
 #[unstable(feature = "anonymous_pipe", issue = "127154")]
diff --git a/library/std/src/os/fd/owned.rs b/library/std/src/os/fd/owned.rs
index 388b8a88a1a..abb13b75f50 100644
--- a/library/std/src/os/fd/owned.rs
+++ b/library/std/src/os/fd/owned.rs
@@ -428,6 +428,14 @@ impl<T: AsFd + ?Sized> AsFd for crate::rc::Rc<T> {
     }
 }
 
+#[unstable(feature = "unique_rc_arc", issue = "112566")]
+impl<T: AsFd + ?Sized> AsFd for crate::rc::UniqueRc<T> {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        (**self).as_fd()
+    }
+}
+
 #[stable(feature = "asfd_ptrs", since = "1.64.0")]
 impl<T: AsFd + ?Sized> AsFd for Box<T> {
     #[inline]
diff --git a/library/std/src/os/fd/raw.rs b/library/std/src/os/fd/raw.rs
index 0d99d5492a2..22f5528248a 100644
--- a/library/std/src/os/fd/raw.rs
+++ b/library/std/src/os/fd/raw.rs
@@ -266,6 +266,14 @@ impl<T: AsRawFd> AsRawFd for crate::rc::Rc<T> {
     }
 }
 
+#[unstable(feature = "unique_rc_arc", issue = "112566")]
+impl<T: AsRawFd + ?Sized> AsRawFd for crate::rc::UniqueRc<T> {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        (**self).as_raw_fd()
+    }
+}
+
 #[stable(feature = "asrawfd_ptrs", since = "1.63.0")]
 impl<T: AsRawFd> AsRawFd for Box<T> {
     #[inline]
diff --git a/library/std/src/os/hurd/mod.rs b/library/std/src/os/hurd/mod.rs
index aee86c7f616..6cd50aeada1 100644
--- a/library/std/src/os/hurd/mod.rs
+++ b/library/std/src/os/hurd/mod.rs
@@ -1,6 +1,7 @@
 //! Hurd-specific definitions
 
 #![stable(feature = "raw_ext", since = "1.1.0")]
+#![forbid(unsafe_op_in_unsafe_fn)]
 
 pub mod fs;
 pub mod raw;
diff --git a/library/std/src/os/windows/io/handle.rs b/library/std/src/os/windows/io/handle.rs
index a4fa94e2b96..76f5f549dd2 100644
--- a/library/std/src/os/windows/io/handle.rs
+++ b/library/std/src/os/windows/io/handle.rs
@@ -485,6 +485,14 @@ impl<T: AsHandle + ?Sized> AsHandle for crate::rc::Rc<T> {
     }
 }
 
+#[unstable(feature = "unique_rc_arc", issue = "112566")]
+impl<T: AsHandle + ?Sized> AsHandle for crate::rc::UniqueRc<T> {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        (**self).as_handle()
+    }
+}
+
 #[stable(feature = "as_windows_ptrs", since = "1.71.0")]
 impl<T: AsHandle + ?Sized> AsHandle for Box<T> {
     #[inline]
diff --git a/library/std/src/os/windows/io/socket.rs b/library/std/src/os/windows/io/socket.rs
index 272641ea6c7..c6d7bad9440 100644
--- a/library/std/src/os/windows/io/socket.rs
+++ b/library/std/src/os/windows/io/socket.rs
@@ -279,6 +279,14 @@ impl<T: AsSocket> AsSocket for crate::rc::Rc<T> {
     }
 }
 
+#[unstable(feature = "unique_rc_arc", issue = "112566")]
+impl<T: AsSocket + ?Sized> AsSocket for crate::rc::UniqueRc<T> {
+    #[inline]
+    fn as_socket(&self) -> BorrowedSocket<'_> {
+        (**self).as_socket()
+    }
+}
+
 #[stable(feature = "as_windows_ptrs", since = "1.71.0")]
 impl<T: AsSocket> AsSocket for Box<T> {
     #[inline]
diff --git a/library/std/src/panicking.rs b/library/std/src/panicking.rs
index 97f800dddaa..dca5ccca0c4 100644
--- a/library/std/src/panicking.rs
+++ b/library/std/src/panicking.rs
@@ -623,7 +623,7 @@ pub fn begin_panic_handler(info: &core::panic::PanicInfo<'_>) -> ! {
             // Lazily, the first time this gets called, run the actual string formatting.
             self.string.get_or_insert_with(|| {
                 let mut s = String::new();
-                let mut fmt = fmt::Formatter::new(&mut s);
+                let mut fmt = fmt::Formatter::new(&mut s, fmt::FormattingOptions::new());
                 let _err = fmt::Display::fmt(&inner, &mut fmt);
                 s
             })
diff --git a/library/std/src/path.rs b/library/std/src/path.rs
index 5b277a982ee..35e920ab344 100644
--- a/library/std/src/path.rs
+++ b/library/std/src/path.rs
@@ -2327,7 +2327,9 @@ impl Path {
             // FIXME: Allow Redox prefixes
             self.has_root() || has_redox_scheme(self.as_u8_slice())
         } else {
-            self.has_root() && (cfg!(any(unix, target_os = "wasi")) || self.prefix().is_some())
+            self.has_root()
+                && (cfg!(any(unix, target_os = "hermit", target_os = "wasi"))
+                    || self.prefix().is_some())
         }
     }
 
diff --git a/library/std/src/pipe.rs b/library/std/src/pipe.rs
index 891032e94a6..06f3fd9fdff 100644
--- a/library/std/src/pipe.rs
+++ b/library/std/src/pipe.rs
@@ -1,20 +1,66 @@
-//! Module for anonymous pipe
+//!  A cross-platform anonymous pipe.
 //!
-//! ```
-//! #![feature(anonymous_pipe)]
+//! This module provides support for anonymous OS pipes, like [pipe] on Linux or [CreatePipe] on
+//! Windows.
+//!
+//! # Behavior
+//!
+//! A pipe is a synchronous, unidirectional data channel between two or more processes, like an
+//! interprocess [`mpsc`](crate::sync::mpsc) provided by the OS. In particular:
+//!
+//! * A read on a [`PipeReader`] blocks until the pipe is non-empty.
+//! * A write on a [`PipeWriter`] blocks when the pipe is full.
+//! * When all copies of a [`PipeWriter`] are closed, a read on the corresponding [`PipeReader`]
+//!   returns EOF.
+//! * [`PipeReader`] can be shared, but only one process will consume the data in the pipe.
+//!
+//! # Capacity
+//!
+//! Pipe capacity is platform dependent. To quote the Linux [man page]:
+//!
+//! > Different implementations have different limits for the pipe capacity. Applications should
+//! > not rely on a particular capacity: an application should be designed so that a reading process
+//! > consumes data as soon as it is available, so that a writing process does not remain blocked.
 //!
+//! # Examples
+//!
+//! ```no_run
+//! #![feature(anonymous_pipe)]
 //! # #[cfg(miri)] fn main() {}
 //! # #[cfg(not(miri))]
 //! # fn main() -> std::io::Result<()> {
-//! let (reader, writer) = std::pipe::pipe()?;
+//! # use std::process::Command;
+//! # use std::io::{Read, Write};
+//! let (ping_rx, mut ping_tx) = std::pipe::pipe()?;
+//! let (mut pong_rx, pong_tx) = std::pipe::pipe()?;
+//!
+//! // Spawn a process that echoes its input.
+//! let mut echo_server = Command::new("cat").stdin(ping_rx).stdout(pong_tx).spawn()?;
+//!
+//! ping_tx.write_all(b"hello")?;
+//! // Close to unblock echo_server's reader.
+//! drop(ping_tx);
+//!
+//! let mut buf = String::new();
+//! // Block until echo_server's writer is closed.
+//! pong_rx.read_to_string(&mut buf)?;
+//! assert_eq!(&buf, "hello");
+//!
+//! echo_server.wait()?;
 //! # Ok(())
 //! # }
 //! ```
-
+//! [pipe]: https://man7.org/linux/man-pages/man2/pipe.2.html
+//! [CreatePipe]: https://learn.microsoft.com/en-us/windows/win32/api/namedpipeapi/nf-namedpipeapi-createpipe
+//! [man page]: https://man7.org/linux/man-pages/man7/pipe.7.html
 use crate::io;
 use crate::sys::anonymous_pipe::{AnonPipe, pipe as pipe_inner};
 
 /// Create anonymous pipe that is close-on-exec and blocking.
+///
+/// # Examples
+///
+/// See the [module-level](crate::pipe) documentation for examples.
 #[unstable(feature = "anonymous_pipe", issue = "127154")]
 #[inline]
 pub fn pipe() -> io::Result<(PipeReader, PipeWriter)> {
@@ -33,6 +79,58 @@ pub struct PipeWriter(pub(crate) AnonPipe);
 
 impl PipeReader {
     /// Create a new [`PipeReader`] instance that shares the same underlying file description.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(anonymous_pipe)]
+    /// # #[cfg(miri)] fn main() {}
+    /// # #[cfg(not(miri))]
+    /// # fn main() -> std::io::Result<()> {
+    /// # use std::fs;
+    /// # use std::io::Write;
+    /// # use std::process::Command;
+    /// const NUM_SLOT: u8 = 2;
+    /// const NUM_PROC: u8 = 5;
+    /// const OUTPUT: &str = "work.txt";
+    ///
+    /// let mut jobs = vec![];
+    /// let (reader, mut writer) = std::pipe::pipe()?;
+    ///
+    /// // Write NUM_SLOT characters the the pipe.
+    /// writer.write_all(&[b'|'; NUM_SLOT as usize])?;
+    ///
+    /// // Spawn several processes that read a character from the pipe, do some work, then
+    /// // write back to the pipe. When the pipe is empty, the processes block, so only
+    /// // NUM_SLOT processes can be working at any given time.
+    /// for _ in 0..NUM_PROC {
+    ///     jobs.push(
+    ///         Command::new("bash")
+    ///             .args(["-c",
+    ///                 &format!(
+    ///                      "read -n 1\n\
+    ///                       echo -n 'x' >> '{OUTPUT}'\n\
+    ///                       echo -n '|'",
+    ///                 ),
+    ///             ])
+    ///             .stdin(reader.try_clone()?)
+    ///             .stdout(writer.try_clone()?)
+    ///             .spawn()?,
+    ///     );
+    /// }
+    ///
+    /// // Wait for all jobs to finish.
+    /// for mut job in jobs {
+    ///     job.wait()?;
+    /// }
+    ///
+    /// // Check our work and clean up.
+    /// let xs = fs::read_to_string(OUTPUT)?;
+    /// fs::remove_file(OUTPUT)?;
+    /// assert_eq!(xs, "x".repeat(NUM_PROC.into()));
+    /// # Ok(())
+    /// # }
+    /// ```
     #[unstable(feature = "anonymous_pipe", issue = "127154")]
     pub fn try_clone(&self) -> io::Result<Self> {
         self.0.try_clone().map(Self)
@@ -41,6 +139,38 @@ impl PipeReader {
 
 impl PipeWriter {
     /// Create a new [`PipeWriter`] instance that shares the same underlying file description.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(anonymous_pipe)]
+    /// # #[cfg(miri)] fn main() {}
+    /// # #[cfg(not(miri))]
+    /// # fn main() -> std::io::Result<()> {
+    /// # use std::process::Command;
+    /// # use std::io::Read;
+    /// let (mut reader, writer) = std::pipe::pipe()?;
+    ///
+    /// // Spawn a process that writes to stdout and stderr.
+    /// let mut peer = Command::new("bash")
+    ///     .args([
+    ///         "-c",
+    ///         "echo -n foo\n\
+    ///          echo -n bar >&2"
+    ///     ])
+    ///     .stdout(writer.try_clone()?)
+    ///     .stderr(writer)
+    ///     .spawn()?;
+    ///
+    /// // Read and check the result.
+    /// let mut msg = String::new();
+    /// reader.read_to_string(&mut msg)?;
+    /// assert_eq!(&msg, "foobar");
+    ///
+    /// peer.wait()?;
+    /// # Ok(())
+    /// # }
+    /// ```
     #[unstable(feature = "anonymous_pipe", issue = "127154")]
     pub fn try_clone(&self) -> io::Result<Self> {
         self.0.try_clone().map(Self)
diff --git a/library/std/src/prelude/common.rs b/library/std/src/prelude/common.rs
index e4731280ffe..22a364074c5 100644
--- a/library/std/src/prelude/common.rs
+++ b/library/std/src/prelude/common.rs
@@ -12,7 +12,8 @@ pub use crate::marker::{Send, Sized, Sync, Unpin};
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)]
 pub use crate::ops::{Drop, Fn, FnMut, FnOnce};
-#[unstable(feature = "async_closure", issue = "62290")]
+#[cfg_attr(bootstrap, unstable(feature = "async_closure", issue = "62290"))]
+#[cfg_attr(not(bootstrap), stable(feature = "async_closure", since = "CURRENT_RUSTC_VERSION"))]
 #[doc(no_inline)]
 pub use crate::ops::{AsyncFn, AsyncFnMut, AsyncFnOnce};
 
diff --git a/library/std/src/prelude/mod.rs b/library/std/src/prelude/mod.rs
index 0c610ba67e6..64349987fcf 100644
--- a/library/std/src/prelude/mod.rs
+++ b/library/std/src/prelude/mod.rs
@@ -25,6 +25,7 @@
 //!
 //! # Prelude contents
 //!
+//! The items included in the prelude depend on the edition of the crate.
 //! The first version of the prelude is used in Rust 2015 and Rust 2018,
 //! and lives in [`std::prelude::v1`].
 //! [`std::prelude::rust_2015`] and [`std::prelude::rust_2018`] re-export this prelude.
@@ -32,8 +33,9 @@
 //!
 //! * <code>[std::marker]::{[Copy], [Send], [Sized], [Sync], [Unpin]}</code>,
 //!   marker traits that indicate fundamental properties of types.
-//! * <code>[std::ops]::{[Drop], [Fn], [FnMut], [FnOnce]}</code>, various
-//!   operations for both destructors and overloading `()`.
+//! * <code>[std::ops]::{[Fn], [FnMut], [FnOnce]}</code>, and their analogous
+//!   async traits, <code>[std::ops]::{[AsyncFn], [AsyncFnMut], [AsyncFnOnce]}</code>.
+//! * <code>[std::ops]::[Drop]</code>, for implementing destructors.
 //! * <code>[std::mem]::[drop]</code>, a convenience function for explicitly
 //!   dropping a value.
 //! * <code>[std::mem]::{[size_of], [size_of_val]}</code>, to get the size of
@@ -67,15 +69,21 @@
 //! The prelude used in Rust 2021, [`std::prelude::rust_2021`], includes all of the above,
 //! and in addition re-exports:
 //!
-//! * <code>[std::convert]::{[TryFrom], [TryInto]}</code>,
+//! * <code>[std::convert]::{[TryFrom], [TryInto]}</code>.
 //! * <code>[std::iter]::[FromIterator]</code>.
 //!
+//! The prelude used in Rust 2024, [`std::prelude::rust_2024`], includes all of the above,
+//! and in addition re-exports:
+//!
+//! * <code>[std::future]::{[Future], [IntoFuture]}</code>.
+//!
 //! [std::borrow]: crate::borrow
 //! [std::boxed]: crate::boxed
 //! [std::clone]: crate::clone
 //! [std::cmp]: crate::cmp
 //! [std::convert]: crate::convert
 //! [std::default]: crate::default
+//! [std::future]: crate::future
 //! [std::iter]: crate::iter
 //! [std::marker]: crate::marker
 //! [std::mem]: crate::mem
@@ -85,6 +93,7 @@
 //! [`std::prelude::rust_2015`]: rust_2015
 //! [`std::prelude::rust_2018`]: rust_2018
 //! [`std::prelude::rust_2021`]: rust_2021
+//! [`std::prelude::rust_2024`]: rust_2024
 //! [std::result]: crate::result
 //! [std::slice]: crate::slice
 //! [std::string]: crate::string
@@ -94,6 +103,8 @@
 //! [book-dtor]: ../../book/ch15-03-drop.html
 //! [book-enums]: ../../book/ch06-01-defining-an-enum.html
 //! [book-iter]: ../../book/ch13-02-iterators.html
+//! [Future]: crate::future::Future
+//! [IntoFuture]: crate::future::IntoFuture
 
 // No formatting: this file is nothing but re-exports, and their order is worth preserving.
 #![cfg_attr(rustfmt, rustfmt::skip)]
@@ -158,12 +169,12 @@ pub mod rust_2021 {
 /// The 2024 version of the prelude of The Rust Standard Library.
 ///
 /// See the [module-level documentation](self) for more.
-#[unstable(feature = "prelude_2024", issue = "121042")]
+#[stable(feature = "prelude_2024", since = "CURRENT_RUSTC_VERSION")]
 pub mod rust_2024 {
     #[stable(feature = "rust1", since = "1.0.0")]
     pub use super::common::*;
 
-    #[unstable(feature = "prelude_2024", issue = "121042")]
+    #[stable(feature = "prelude_2024", since = "CURRENT_RUSTC_VERSION")]
     #[doc(no_inline)]
     pub use core::prelude::rust_2024::*;
 }
diff --git a/library/std/src/sync/mutex.rs b/library/std/src/sync/mutex.rs
index fe2aca031a2..e28c2090afe 100644
--- a/library/std/src/sync/mutex.rs
+++ b/library/std/src/sync/mutex.rs
@@ -4,10 +4,10 @@ mod tests;
 use crate::cell::UnsafeCell;
 use crate::fmt;
 use crate::marker::PhantomData;
-use crate::mem::ManuallyDrop;
+use crate::mem::{self, ManuallyDrop};
 use crate::ops::{Deref, DerefMut};
 use crate::ptr::NonNull;
-use crate::sync::{LockResult, TryLockError, TryLockResult, poison};
+use crate::sync::{LockResult, PoisonError, TryLockError, TryLockResult, poison};
 use crate::sys::sync as sys;
 
 /// A mutual exclusion primitive useful for protecting shared data
@@ -273,6 +273,100 @@ impl<T> Mutex<T> {
     pub const fn new(t: T) -> Mutex<T> {
         Mutex { inner: sys::Mutex::new(), poison: poison::Flag::new(), data: UnsafeCell::new(t) }
     }
+
+    /// Returns the contained value by cloning it.
+    ///
+    /// # Errors
+    ///
+    /// If another user of this mutex panicked while holding the mutex, then
+    /// this call will return an error instead.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(lock_value_accessors)]
+    ///
+    /// use std::sync::Mutex;
+    ///
+    /// let mut mutex = Mutex::new(7);
+    ///
+    /// assert_eq!(mutex.get_cloned().unwrap(), 7);
+    /// ```
+    #[unstable(feature = "lock_value_accessors", issue = "133407")]
+    pub fn get_cloned(&self) -> Result<T, PoisonError<()>>
+    where
+        T: Clone,
+    {
+        match self.lock() {
+            Ok(guard) => Ok((*guard).clone()),
+            Err(_) => Err(PoisonError::new(())),
+        }
+    }
+
+    /// Sets the contained value.
+    ///
+    /// # Errors
+    ///
+    /// If another user of this mutex panicked while holding the mutex, then
+    /// this call will return an error containing the provided `value` instead.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(lock_value_accessors)]
+    ///
+    /// use std::sync::Mutex;
+    ///
+    /// let mut mutex = Mutex::new(7);
+    ///
+    /// assert_eq!(mutex.get_cloned().unwrap(), 7);
+    /// mutex.set(11).unwrap();
+    /// assert_eq!(mutex.get_cloned().unwrap(), 11);
+    /// ```
+    #[unstable(feature = "lock_value_accessors", issue = "133407")]
+    pub fn set(&self, value: T) -> Result<(), PoisonError<T>> {
+        if mem::needs_drop::<T>() {
+            // If the contained value has non-trivial destructor, we
+            // call that destructor after the lock being released.
+            self.replace(value).map(drop)
+        } else {
+            match self.lock() {
+                Ok(mut guard) => {
+                    *guard = value;
+
+                    Ok(())
+                }
+                Err(_) => Err(PoisonError::new(value)),
+            }
+        }
+    }
+
+    /// Replaces the contained value with `value`, and returns the old contained value.
+    ///
+    /// # Errors
+    ///
+    /// If another user of this mutex panicked while holding the mutex, then
+    /// this call will return an error containing the provided `value` instead.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(lock_value_accessors)]
+    ///
+    /// use std::sync::Mutex;
+    ///
+    /// let mut mutex = Mutex::new(7);
+    ///
+    /// assert_eq!(mutex.replace(11).unwrap(), 7);
+    /// assert_eq!(mutex.get_cloned().unwrap(), 11);
+    /// ```
+    #[unstable(feature = "lock_value_accessors", issue = "133407")]
+    pub fn replace(&self, value: T) -> LockResult<T> {
+        match self.lock() {
+            Ok(mut guard) => Ok(mem::replace(&mut *guard, value)),
+            Err(_) => Err(PoisonError::new(value)),
+        }
+    }
 }
 
 impl<T: ?Sized> Mutex<T> {
@@ -290,7 +384,8 @@ impl<T: ?Sized> Mutex<T> {
     /// # Errors
     ///
     /// If another user of this mutex panicked while holding the mutex, then
-    /// this call will return an error once the mutex is acquired.
+    /// this call will return an error once the mutex is acquired. The acquired
+    /// mutex guard will be contained in the returned error.
     ///
     /// # Panics
     ///
@@ -331,7 +426,8 @@ impl<T: ?Sized> Mutex<T> {
     ///
     /// If another user of this mutex panicked while holding the mutex, then
     /// this call will return the [`Poisoned`] error if the mutex would
-    /// otherwise be acquired.
+    /// otherwise be acquired. An acquired lock guard will be contained
+    /// in the returned error.
     ///
     /// If the mutex could not be acquired because it is already locked, then
     /// this call will return the [`WouldBlock`] error.
@@ -438,7 +534,8 @@ impl<T: ?Sized> Mutex<T> {
     /// # Errors
     ///
     /// If another user of this mutex panicked while holding the mutex, then
-    /// this call will return an error instead.
+    /// this call will return an error containing the the underlying data
+    /// instead.
     ///
     /// # Examples
     ///
@@ -465,7 +562,8 @@ impl<T: ?Sized> Mutex<T> {
     /// # Errors
     ///
     /// If another user of this mutex panicked while holding the mutex, then
-    /// this call will return an error instead.
+    /// this call will return an error containing a mutable reference to the
+    /// underlying data instead.
     ///
     /// # Examples
     ///
diff --git a/library/std/src/sync/mutex/tests.rs b/library/std/src/sync/mutex/tests.rs
index 19ec096c593..395c8aada08 100644
--- a/library/std/src/sync/mutex/tests.rs
+++ b/library/std/src/sync/mutex/tests.rs
@@ -1,13 +1,34 @@
+use crate::fmt::Debug;
+use crate::ops::FnMut;
+use crate::panic::{self, AssertUnwindSafe};
 use crate::sync::atomic::{AtomicUsize, Ordering};
 use crate::sync::mpsc::channel;
 use crate::sync::{Arc, Condvar, MappedMutexGuard, Mutex, MutexGuard, TryLockError};
-use crate::thread;
+use crate::{hint, mem, thread};
 
 struct Packet<T>(Arc<(Mutex<T>, Condvar)>);
 
 #[derive(Eq, PartialEq, Debug)]
 struct NonCopy(i32);
 
+#[derive(Eq, PartialEq, Debug)]
+struct NonCopyNeedsDrop(i32);
+
+impl Drop for NonCopyNeedsDrop {
+    fn drop(&mut self) {
+        hint::black_box(());
+    }
+}
+
+#[test]
+fn test_needs_drop() {
+    assert!(!mem::needs_drop::<NonCopy>());
+    assert!(mem::needs_drop::<NonCopyNeedsDrop>());
+}
+
+#[derive(Clone, Eq, PartialEq, Debug)]
+struct Cloneable(i32);
+
 #[test]
 fn smoke() {
     let m = Mutex::new(());
@@ -57,6 +78,21 @@ fn try_lock() {
     *m.try_lock().unwrap() = ();
 }
 
+fn new_poisoned_mutex<T>(value: T) -> Mutex<T> {
+    let mutex = Mutex::new(value);
+
+    let catch_unwind_result = panic::catch_unwind(AssertUnwindSafe(|| {
+        let _guard = mutex.lock().unwrap();
+
+        panic!("test panic to poison mutex");
+    }));
+
+    assert!(catch_unwind_result.is_err());
+    assert!(mutex.is_poisoned());
+
+    mutex
+}
+
 #[test]
 fn test_into_inner() {
     let m = Mutex::new(NonCopy(10));
@@ -83,22 +119,32 @@ fn test_into_inner_drop() {
 
 #[test]
 fn test_into_inner_poison() {
-    let m = Arc::new(Mutex::new(NonCopy(10)));
-    let m2 = m.clone();
-    let _ = thread::spawn(move || {
-        let _lock = m2.lock().unwrap();
-        panic!("test panic in inner thread to poison mutex");
-    })
-    .join();
+    let m = new_poisoned_mutex(NonCopy(10));
 
-    assert!(m.is_poisoned());
-    match Arc::try_unwrap(m).unwrap().into_inner() {
+    match m.into_inner() {
         Err(e) => assert_eq!(e.into_inner(), NonCopy(10)),
         Ok(x) => panic!("into_inner of poisoned Mutex is Ok: {x:?}"),
     }
 }
 
 #[test]
+fn test_get_cloned() {
+    let m = Mutex::new(Cloneable(10));
+
+    assert_eq!(m.get_cloned().unwrap(), Cloneable(10));
+}
+
+#[test]
+fn test_get_cloned_poison() {
+    let m = new_poisoned_mutex(Cloneable(10));
+
+    match m.get_cloned() {
+        Err(e) => assert_eq!(e.into_inner(), ()),
+        Ok(x) => panic!("get of poisoned Mutex is Ok: {x:?}"),
+    }
+}
+
+#[test]
 fn test_get_mut() {
     let mut m = Mutex::new(NonCopy(10));
     *m.get_mut().unwrap() = NonCopy(20);
@@ -107,22 +153,91 @@ fn test_get_mut() {
 
 #[test]
 fn test_get_mut_poison() {
-    let m = Arc::new(Mutex::new(NonCopy(10)));
-    let m2 = m.clone();
-    let _ = thread::spawn(move || {
-        let _lock = m2.lock().unwrap();
-        panic!("test panic in inner thread to poison mutex");
-    })
-    .join();
+    let mut m = new_poisoned_mutex(NonCopy(10));
 
-    assert!(m.is_poisoned());
-    match Arc::try_unwrap(m).unwrap().get_mut() {
+    match m.get_mut() {
         Err(e) => assert_eq!(*e.into_inner(), NonCopy(10)),
         Ok(x) => panic!("get_mut of poisoned Mutex is Ok: {x:?}"),
     }
 }
 
 #[test]
+fn test_set() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = Mutex::new(init());
+
+        assert_eq!(*m.lock().unwrap(), init());
+        m.set(value()).unwrap();
+        assert_eq!(*m.lock().unwrap(), value());
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
+fn test_set_poison() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = new_poisoned_mutex(init());
+
+        match m.set(value()) {
+            Err(e) => {
+                assert_eq!(e.into_inner(), value());
+                assert_eq!(m.into_inner().unwrap_err().into_inner(), init());
+            }
+            Ok(x) => panic!("set of poisoned Mutex is Ok: {x:?}"),
+        }
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
+fn test_replace() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = Mutex::new(init());
+
+        assert_eq!(*m.lock().unwrap(), init());
+        assert_eq!(m.replace(value()).unwrap(), init());
+        assert_eq!(*m.lock().unwrap(), value());
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
+fn test_replace_poison() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = new_poisoned_mutex(init());
+
+        match m.replace(value()) {
+            Err(e) => {
+                assert_eq!(e.into_inner(), value());
+                assert_eq!(m.into_inner().unwrap_err().into_inner(), init());
+            }
+            Ok(x) => panic!("replace of poisoned Mutex is Ok: {x:?}"),
+        }
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
 fn test_mutex_arc_condvar() {
     let packet = Packet(Arc::new((Mutex::new(false), Condvar::new())));
     let packet2 = Packet(packet.0.clone());
@@ -269,7 +384,7 @@ fn test_mapping_mapped_guard() {
 fn panic_while_mapping_unlocked_poison() {
     let lock = Mutex::new(());
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.lock().unwrap();
         let _guard = MutexGuard::map::<(), _>(guard, |_| panic!());
     });
@@ -282,7 +397,7 @@ fn panic_while_mapping_unlocked_poison() {
         Err(TryLockError::Poisoned(_)) => {}
     }
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.lock().unwrap();
         let _guard = MutexGuard::try_map::<(), _>(guard, |_| panic!());
     });
@@ -295,7 +410,7 @@ fn panic_while_mapping_unlocked_poison() {
         Err(TryLockError::Poisoned(_)) => {}
     }
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.lock().unwrap();
         let guard = MutexGuard::map::<(), _>(guard, |val| val);
         let _guard = MappedMutexGuard::map::<(), _>(guard, |_| panic!());
@@ -309,7 +424,7 @@ fn panic_while_mapping_unlocked_poison() {
         Err(TryLockError::Poisoned(_)) => {}
     }
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.lock().unwrap();
         let guard = MutexGuard::map::<(), _>(guard, |val| val);
         let _guard = MappedMutexGuard::try_map::<(), _>(guard, |_| panic!());
diff --git a/library/std/src/sync/poison.rs b/library/std/src/sync/poison.rs
index da66a088e51..9eb900c2103 100644
--- a/library/std/src/sync/poison.rs
+++ b/library/std/src/sync/poison.rs
@@ -87,8 +87,8 @@ pub struct Guard {
 ///
 /// Both [`Mutex`]es and [`RwLock`]s are poisoned whenever a thread fails while the lock
 /// is held. The precise semantics for when a lock is poisoned is documented on
-/// each lock, but once a lock is poisoned then all future acquisitions will
-/// return this error.
+/// each lock. For a lock in the poisoned state, unless the state is cleared manually,
+/// all future acquisitions will return this error.
 ///
 /// # Examples
 ///
@@ -118,7 +118,7 @@ pub struct Guard {
 /// [`RwLock`]: crate::sync::RwLock
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct PoisonError<T> {
-    guard: T,
+    data: T,
     #[cfg(not(panic = "unwind"))]
     _never: !,
 }
@@ -147,14 +147,15 @@ pub enum TryLockError<T> {
 /// A type alias for the result of a lock method which can be poisoned.
 ///
 /// The [`Ok`] variant of this result indicates that the primitive was not
-/// poisoned, and the `Guard` is contained within. The [`Err`] variant indicates
+/// poisoned, and the operation result is contained within. The [`Err`] variant indicates
 /// that the primitive was poisoned. Note that the [`Err`] variant *also* carries
-/// the associated guard, and it can be acquired through the [`into_inner`]
-/// method.
+/// an associated value assigned by the lock method, and it can be acquired through the
+/// [`into_inner`] method. The semantics of the associated value depends on the corresponding
+/// lock method.
 ///
 /// [`into_inner`]: PoisonError::into_inner
 #[stable(feature = "rust1", since = "1.0.0")]
-pub type LockResult<Guard> = Result<Guard, PoisonError<Guard>>;
+pub type LockResult<T> = Result<T, PoisonError<T>>;
 
 /// A type alias for the result of a nonblocking locking method.
 ///
@@ -195,8 +196,8 @@ impl<T> PoisonError<T> {
     /// This method may panic if std was built with `panic="abort"`.
     #[cfg(panic = "unwind")]
     #[stable(feature = "sync_poison", since = "1.2.0")]
-    pub fn new(guard: T) -> PoisonError<T> {
-        PoisonError { guard }
+    pub fn new(data: T) -> PoisonError<T> {
+        PoisonError { data }
     }
 
     /// Creates a `PoisonError`.
@@ -208,12 +209,12 @@ impl<T> PoisonError<T> {
     #[cfg(not(panic = "unwind"))]
     #[stable(feature = "sync_poison", since = "1.2.0")]
     #[track_caller]
-    pub fn new(_guard: T) -> PoisonError<T> {
+    pub fn new(_data: T) -> PoisonError<T> {
         panic!("PoisonError created in a libstd built with panic=\"abort\"")
     }
 
     /// Consumes this error indicating that a lock is poisoned, returning the
-    /// underlying guard to allow access regardless.
+    /// associated data.
     ///
     /// # Examples
     ///
@@ -238,21 +239,21 @@ impl<T> PoisonError<T> {
     /// ```
     #[stable(feature = "sync_poison", since = "1.2.0")]
     pub fn into_inner(self) -> T {
-        self.guard
+        self.data
     }
 
     /// Reaches into this error indicating that a lock is poisoned, returning a
-    /// reference to the underlying guard to allow access regardless.
+    /// reference to the associated data.
     #[stable(feature = "sync_poison", since = "1.2.0")]
     pub fn get_ref(&self) -> &T {
-        &self.guard
+        &self.data
     }
 
     /// Reaches into this error indicating that a lock is poisoned, returning a
-    /// mutable reference to the underlying guard to allow access regardless.
+    /// mutable reference to the associated data.
     #[stable(feature = "sync_poison", since = "1.2.0")]
     pub fn get_mut(&mut self) -> &mut T {
-        &mut self.guard
+        &mut self.data
     }
 }
 
@@ -322,6 +323,6 @@ where
     match result {
         Ok(t) => Ok(f(t)),
         #[cfg(panic = "unwind")]
-        Err(PoisonError { guard }) => Err(PoisonError::new(f(guard))),
+        Err(PoisonError { data }) => Err(PoisonError::new(f(data))),
     }
 }
diff --git a/library/std/src/sync/rwlock.rs b/library/std/src/sync/rwlock.rs
index d55d1c80dca..1519baf99a8 100644
--- a/library/std/src/sync/rwlock.rs
+++ b/library/std/src/sync/rwlock.rs
@@ -4,7 +4,7 @@ mod tests;
 use crate::cell::UnsafeCell;
 use crate::fmt;
 use crate::marker::PhantomData;
-use crate::mem::{ManuallyDrop, forget};
+use crate::mem::{self, ManuallyDrop, forget};
 use crate::ops::{Deref, DerefMut};
 use crate::ptr::NonNull;
 use crate::sync::{LockResult, PoisonError, TryLockError, TryLockResult, poison};
@@ -224,6 +224,103 @@ impl<T> RwLock<T> {
     pub const fn new(t: T) -> RwLock<T> {
         RwLock { inner: sys::RwLock::new(), poison: poison::Flag::new(), data: UnsafeCell::new(t) }
     }
+
+    /// Returns the contained value by cloning it.
+    ///
+    /// # Errors
+    ///
+    /// This function will return an error if the `RwLock` is poisoned. An
+    /// `RwLock` is poisoned whenever a writer panics while holding an exclusive
+    /// lock.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(lock_value_accessors)]
+    ///
+    /// use std::sync::RwLock;
+    ///
+    /// let mut lock = RwLock::new(7);
+    ///
+    /// assert_eq!(lock.get_cloned().unwrap(), 7);
+    /// ```
+    #[unstable(feature = "lock_value_accessors", issue = "133407")]
+    pub fn get_cloned(&self) -> Result<T, PoisonError<()>>
+    where
+        T: Clone,
+    {
+        match self.read() {
+            Ok(guard) => Ok((*guard).clone()),
+            Err(_) => Err(PoisonError::new(())),
+        }
+    }
+
+    /// Sets the contained value.
+    ///
+    /// # Errors
+    ///
+    /// This function will return an error containing the provided `value` if
+    /// the `RwLock` is poisoned. An `RwLock` is poisoned whenever a writer
+    /// panics while holding an exclusive lock.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(lock_value_accessors)]
+    ///
+    /// use std::sync::RwLock;
+    ///
+    /// let mut lock = RwLock::new(7);
+    ///
+    /// assert_eq!(lock.get_cloned().unwrap(), 7);
+    /// lock.set(11).unwrap();
+    /// assert_eq!(lock.get_cloned().unwrap(), 11);
+    /// ```
+    #[unstable(feature = "lock_value_accessors", issue = "133407")]
+    pub fn set(&self, value: T) -> Result<(), PoisonError<T>> {
+        if mem::needs_drop::<T>() {
+            // If the contained value has non-trivial destructor, we
+            // call that destructor after the lock being released.
+            self.replace(value).map(drop)
+        } else {
+            match self.write() {
+                Ok(mut guard) => {
+                    *guard = value;
+
+                    Ok(())
+                }
+                Err(_) => Err(PoisonError::new(value)),
+            }
+        }
+    }
+
+    /// Replaces the contained value with `value`, and returns the old contained value.
+    ///
+    /// # Errors
+    ///
+    /// This function will return an error containing the provided `value` if
+    /// the `RwLock` is poisoned. An `RwLock` is poisoned whenever a writer
+    /// panics while holding an exclusive lock.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(lock_value_accessors)]
+    ///
+    /// use std::sync::RwLock;
+    ///
+    /// let mut lock = RwLock::new(7);
+    ///
+    /// assert_eq!(lock.replace(11).unwrap(), 7);
+    /// assert_eq!(lock.get_cloned().unwrap(), 11);
+    /// ```
+    #[unstable(feature = "lock_value_accessors", issue = "133407")]
+    pub fn replace(&self, value: T) -> LockResult<T> {
+        match self.write() {
+            Ok(mut guard) => Ok(mem::replace(&mut *guard, value)),
+            Err(_) => Err(PoisonError::new(value)),
+        }
+    }
 }
 
 impl<T: ?Sized> RwLock<T> {
@@ -244,7 +341,8 @@ impl<T: ?Sized> RwLock<T> {
     /// This function will return an error if the `RwLock` is poisoned. An
     /// `RwLock` is poisoned whenever a writer panics while holding an exclusive
     /// lock. The failure will occur immediately after the lock has been
-    /// acquired.
+    /// acquired. The acquired lock guard will be contained in the returned
+    /// error.
     ///
     /// # Panics
     ///
@@ -292,7 +390,8 @@ impl<T: ?Sized> RwLock<T> {
     /// This function will return the [`Poisoned`] error if the `RwLock` is
     /// poisoned. An `RwLock` is poisoned whenever a writer panics while holding
     /// an exclusive lock. `Poisoned` will only be returned if the lock would
-    /// have otherwise been acquired.
+    /// have otherwise been acquired. An acquired lock guard will be contained
+    /// in the returned error.
     ///
     /// This function will return the [`WouldBlock`] error if the `RwLock` could
     /// not be acquired because it was already locked exclusively.
@@ -337,7 +436,8 @@ impl<T: ?Sized> RwLock<T> {
     ///
     /// This function will return an error if the `RwLock` is poisoned. An
     /// `RwLock` is poisoned whenever a writer panics while holding an exclusive
-    /// lock. An error will be returned when the lock is acquired.
+    /// lock. An error will be returned when the lock is acquired. The acquired
+    /// lock guard will be contained in the returned error.
     ///
     /// # Panics
     ///
@@ -380,7 +480,8 @@ impl<T: ?Sized> RwLock<T> {
     /// This function will return the [`Poisoned`] error if the `RwLock` is
     /// poisoned. An `RwLock` is poisoned whenever a writer panics while holding
     /// an exclusive lock. `Poisoned` will only be returned if the lock would
-    /// have otherwise been acquired.
+    /// have otherwise been acquired. An acquired lock guard will be contained
+    /// in the returned error.
     ///
     /// This function will return the [`WouldBlock`] error if the `RwLock` could
     /// not be acquired because it was already locked exclusively.
@@ -481,10 +582,10 @@ impl<T: ?Sized> RwLock<T> {
     ///
     /// # Errors
     ///
-    /// This function will return an error if the `RwLock` is poisoned. An
-    /// `RwLock` is poisoned whenever a writer panics while holding an exclusive
-    /// lock. An error will only be returned if the lock would have otherwise
-    /// been acquired.
+    /// This function will return an error containing the underlying data if
+    /// the `RwLock` is poisoned. An `RwLock` is poisoned whenever a writer
+    /// panics while holding an exclusive lock. An error will only be returned
+    /// if the lock would have otherwise been acquired.
     ///
     /// # Examples
     ///
@@ -514,10 +615,11 @@ impl<T: ?Sized> RwLock<T> {
     ///
     /// # Errors
     ///
-    /// This function will return an error if the `RwLock` is poisoned. An
-    /// `RwLock` is poisoned whenever a writer panics while holding an exclusive
-    /// lock. An error will only be returned if the lock would have otherwise
-    /// been acquired.
+    /// This function will return an error containing a mutable reference to
+    /// the underlying data if the `RwLock` is poisoned. An `RwLock` is
+    /// poisoned whenever a writer panics while holding an exclusive lock.
+    /// An error will only be returned if the lock would have otherwise been
+    /// acquired.
     ///
     /// # Examples
     ///
diff --git a/library/std/src/sync/rwlock/tests.rs b/library/std/src/sync/rwlock/tests.rs
index 48d442921f7..057c2f1a5d7 100644
--- a/library/std/src/sync/rwlock/tests.rs
+++ b/library/std/src/sync/rwlock/tests.rs
@@ -1,16 +1,37 @@
 use rand::Rng;
 
+use crate::fmt::Debug;
+use crate::ops::FnMut;
+use crate::panic::{self, AssertUnwindSafe};
 use crate::sync::atomic::{AtomicUsize, Ordering};
 use crate::sync::mpsc::channel;
 use crate::sync::{
     Arc, MappedRwLockReadGuard, MappedRwLockWriteGuard, RwLock, RwLockReadGuard, RwLockWriteGuard,
     TryLockError,
 };
-use crate::thread;
+use crate::{hint, mem, thread};
 
 #[derive(Eq, PartialEq, Debug)]
 struct NonCopy(i32);
 
+#[derive(Eq, PartialEq, Debug)]
+struct NonCopyNeedsDrop(i32);
+
+impl Drop for NonCopyNeedsDrop {
+    fn drop(&mut self) {
+        hint::black_box(());
+    }
+}
+
+#[test]
+fn test_needs_drop() {
+    assert!(!mem::needs_drop::<NonCopy>());
+    assert!(mem::needs_drop::<NonCopyNeedsDrop>());
+}
+
+#[derive(Clone, Eq, PartialEq, Debug)]
+struct Cloneable(i32);
+
 #[test]
 fn smoke() {
     let l = RwLock::new(());
@@ -255,6 +276,21 @@ fn test_rwlock_try_write() {
     drop(mapped_read_guard);
 }
 
+fn new_poisoned_rwlock<T>(value: T) -> RwLock<T> {
+    let lock = RwLock::new(value);
+
+    let catch_unwind_result = panic::catch_unwind(AssertUnwindSafe(|| {
+        let _guard = lock.write().unwrap();
+
+        panic!("test panic to poison RwLock");
+    }));
+
+    assert!(catch_unwind_result.is_err());
+    assert!(lock.is_poisoned());
+
+    lock
+}
+
 #[test]
 fn test_into_inner() {
     let m = RwLock::new(NonCopy(10));
@@ -281,22 +317,32 @@ fn test_into_inner_drop() {
 
 #[test]
 fn test_into_inner_poison() {
-    let m = Arc::new(RwLock::new(NonCopy(10)));
-    let m2 = m.clone();
-    let _ = thread::spawn(move || {
-        let _lock = m2.write().unwrap();
-        panic!("test panic in inner thread to poison RwLock");
-    })
-    .join();
+    let m = new_poisoned_rwlock(NonCopy(10));
 
-    assert!(m.is_poisoned());
-    match Arc::try_unwrap(m).unwrap().into_inner() {
+    match m.into_inner() {
         Err(e) => assert_eq!(e.into_inner(), NonCopy(10)),
         Ok(x) => panic!("into_inner of poisoned RwLock is Ok: {x:?}"),
     }
 }
 
 #[test]
+fn test_get_cloned() {
+    let m = RwLock::new(Cloneable(10));
+
+    assert_eq!(m.get_cloned().unwrap(), Cloneable(10));
+}
+
+#[test]
+fn test_get_cloned_poison() {
+    let m = new_poisoned_rwlock(Cloneable(10));
+
+    match m.get_cloned() {
+        Err(e) => assert_eq!(e.into_inner(), ()),
+        Ok(x) => panic!("get of poisoned RwLock is Ok: {x:?}"),
+    }
+}
+
+#[test]
 fn test_get_mut() {
     let mut m = RwLock::new(NonCopy(10));
     *m.get_mut().unwrap() = NonCopy(20);
@@ -305,22 +351,91 @@ fn test_get_mut() {
 
 #[test]
 fn test_get_mut_poison() {
-    let m = Arc::new(RwLock::new(NonCopy(10)));
-    let m2 = m.clone();
-    let _ = thread::spawn(move || {
-        let _lock = m2.write().unwrap();
-        panic!("test panic in inner thread to poison RwLock");
-    })
-    .join();
+    let mut m = new_poisoned_rwlock(NonCopy(10));
 
-    assert!(m.is_poisoned());
-    match Arc::try_unwrap(m).unwrap().get_mut() {
+    match m.get_mut() {
         Err(e) => assert_eq!(*e.into_inner(), NonCopy(10)),
         Ok(x) => panic!("get_mut of poisoned RwLock is Ok: {x:?}"),
     }
 }
 
 #[test]
+fn test_set() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = RwLock::new(init());
+
+        assert_eq!(*m.read().unwrap(), init());
+        m.set(value()).unwrap();
+        assert_eq!(*m.read().unwrap(), value());
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
+fn test_set_poison() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = new_poisoned_rwlock(init());
+
+        match m.set(value()) {
+            Err(e) => {
+                assert_eq!(e.into_inner(), value());
+                assert_eq!(m.into_inner().unwrap_err().into_inner(), init());
+            }
+            Ok(x) => panic!("set of poisoned RwLock is Ok: {x:?}"),
+        }
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
+fn test_replace() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = RwLock::new(init());
+
+        assert_eq!(*m.read().unwrap(), init());
+        assert_eq!(m.replace(value()).unwrap(), init());
+        assert_eq!(*m.read().unwrap(), value());
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
+fn test_replace_poison() {
+    fn inner<T>(mut init: impl FnMut() -> T, mut value: impl FnMut() -> T)
+    where
+        T: Debug + Eq,
+    {
+        let m = new_poisoned_rwlock(init());
+
+        match m.replace(value()) {
+            Err(e) => {
+                assert_eq!(e.into_inner(), value());
+                assert_eq!(m.into_inner().unwrap_err().into_inner(), init());
+            }
+            Ok(x) => panic!("replace of poisoned RwLock is Ok: {x:?}"),
+        }
+    }
+
+    inner(|| NonCopy(10), || NonCopy(20));
+    inner(|| NonCopyNeedsDrop(10), || NonCopyNeedsDrop(20));
+}
+
+#[test]
 fn test_read_guard_covariance() {
     fn do_stuff<'a>(_: RwLockReadGuard<'_, &'a i32>, _: &'a i32) {}
     let j: i32 = 5;
@@ -370,7 +485,7 @@ fn test_mapping_mapped_guard() {
 fn panic_while_mapping_read_unlocked_no_poison() {
     let lock = RwLock::new(());
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.read().unwrap();
         let _guard = RwLockReadGuard::map::<(), _>(guard, |_| panic!());
     });
@@ -385,7 +500,7 @@ fn panic_while_mapping_read_unlocked_no_poison() {
         }
     }
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.read().unwrap();
         let _guard = RwLockReadGuard::try_map::<(), _>(guard, |_| panic!());
     });
@@ -400,7 +515,7 @@ fn panic_while_mapping_read_unlocked_no_poison() {
         }
     }
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.read().unwrap();
         let guard = RwLockReadGuard::map::<(), _>(guard, |val| val);
         let _guard = MappedRwLockReadGuard::map::<(), _>(guard, |_| panic!());
@@ -416,7 +531,7 @@ fn panic_while_mapping_read_unlocked_no_poison() {
         }
     }
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.read().unwrap();
         let guard = RwLockReadGuard::map::<(), _>(guard, |val| val);
         let _guard = MappedRwLockReadGuard::try_map::<(), _>(guard, |_| panic!());
@@ -439,7 +554,7 @@ fn panic_while_mapping_read_unlocked_no_poison() {
 fn panic_while_mapping_write_unlocked_poison() {
     let lock = RwLock::new(());
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.write().unwrap();
         let _guard = RwLockWriteGuard::map::<(), _>(guard, |_| panic!());
     });
@@ -452,7 +567,7 @@ fn panic_while_mapping_write_unlocked_poison() {
         Err(TryLockError::Poisoned(_)) => {}
     }
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.write().unwrap();
         let _guard = RwLockWriteGuard::try_map::<(), _>(guard, |_| panic!());
     });
@@ -467,7 +582,7 @@ fn panic_while_mapping_write_unlocked_poison() {
         Err(TryLockError::Poisoned(_)) => {}
     }
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.write().unwrap();
         let guard = RwLockWriteGuard::map::<(), _>(guard, |val| val);
         let _guard = MappedRwLockWriteGuard::map::<(), _>(guard, |_| panic!());
@@ -483,7 +598,7 @@ fn panic_while_mapping_write_unlocked_poison() {
         Err(TryLockError::Poisoned(_)) => {}
     }
 
-    let _ = crate::panic::catch_unwind(|| {
+    let _ = panic::catch_unwind(|| {
         let guard = lock.write().unwrap();
         let guard = RwLockWriteGuard::map::<(), _>(guard, |val| val);
         let _guard = MappedRwLockWriteGuard::try_map::<(), _>(guard, |_| panic!());
diff --git a/library/std/src/sys/backtrace.rs b/library/std/src/sys/backtrace.rs
index 4d939e175cf..efa6a896dad 100644
--- a/library/std/src/sys/backtrace.rs
+++ b/library/std/src/sys/backtrace.rs
@@ -58,8 +58,8 @@ unsafe fn _print_fmt(fmt: &mut fmt::Formatter<'_>, print_fmt: PrintFmt) -> fmt::
     let mut res = Ok(());
     let mut omitted_count: usize = 0;
     let mut first_omit = true;
-    // Start immediately if we're not using a short backtrace.
-    let mut start = print_fmt != PrintFmt::Short;
+    // If we're using a short backtrace, ignore all frames until we're told to start printing.
+    let mut print = print_fmt != PrintFmt::Short;
     set_image_base();
     // SAFETY: we roll our own locking in this town
     unsafe {
@@ -72,27 +72,25 @@ unsafe fn _print_fmt(fmt: &mut fmt::Formatter<'_>, print_fmt: PrintFmt) -> fmt::
             backtrace_rs::resolve_frame_unsynchronized(frame, |symbol| {
                 hit = true;
 
-                // Any frames between `__rust_begin_short_backtrace` and `__rust_end_short_backtrace`
-                // are omitted from the backtrace in short mode, `__rust_end_short_backtrace` will be
-                // called before the panic hook, so we won't ignore any frames if there is no
-                // invoke of `__rust_begin_short_backtrace`.
+                // `__rust_end_short_backtrace` means we are done hiding symbols
+                // for now. Print until we see `__rust_begin_short_backtrace`.
                 if print_fmt == PrintFmt::Short {
                     if let Some(sym) = symbol.name().and_then(|s| s.as_str()) {
-                        if start && sym.contains("__rust_begin_short_backtrace") {
-                            start = false;
+                        if sym.contains("__rust_end_short_backtrace") {
+                            print = true;
                             return;
                         }
-                        if sym.contains("__rust_end_short_backtrace") {
-                            start = true;
+                        if print && sym.contains("__rust_begin_short_backtrace") {
+                            print = false;
                             return;
                         }
-                        if !start {
+                        if !print {
                             omitted_count += 1;
                         }
                     }
                 }
 
-                if start {
+                if print {
                     if omitted_count > 0 {
                         debug_assert!(print_fmt == PrintFmt::Short);
                         // only print the message between the middle of frames
@@ -112,7 +110,7 @@ unsafe fn _print_fmt(fmt: &mut fmt::Formatter<'_>, print_fmt: PrintFmt) -> fmt::
             });
             #[cfg(target_os = "nto")]
             if libc::__my_thread_exit as *mut libc::c_void == frame.ip() {
-                if !hit && start {
+                if !hit && print {
                     use crate::backtrace_rs::SymbolName;
                     res = bt_fmt.frame().print_raw(
                         frame.ip(),
@@ -123,7 +121,7 @@ unsafe fn _print_fmt(fmt: &mut fmt::Formatter<'_>, print_fmt: PrintFmt) -> fmt::
                 }
                 return false;
             }
-            if !hit && start {
+            if !hit && print {
                 res = bt_fmt.frame().print_raw(frame.ip(), None, None, None);
             }
 
diff --git a/library/std/src/sys/pal/hermit/fs.rs b/library/std/src/sys/pal/hermit/fs.rs
index 11862a07608..88fc4068719 100644
--- a/library/std/src/sys/pal/hermit/fs.rs
+++ b/library/std/src/sys/pal/hermit/fs.rs
@@ -3,7 +3,7 @@ use super::hermit_abi::{
     self, DT_DIR, DT_LNK, DT_REG, DT_UNKNOWN, O_APPEND, O_CREAT, O_DIRECTORY, O_EXCL, O_RDONLY,
     O_RDWR, O_TRUNC, O_WRONLY, S_IFDIR, S_IFLNK, S_IFMT, S_IFREG, dirent64, stat as stat_struct,
 };
-use crate::ffi::{CStr, OsStr, OsString};
+use crate::ffi::{CStr, OsStr, OsString, c_char};
 use crate::io::{self, BorrowedCursor, Error, ErrorKind, IoSlice, IoSliceMut, SeekFrom};
 use crate::os::hermit::ffi::OsStringExt;
 use crate::os::hermit::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, RawFd};
@@ -204,7 +204,7 @@ impl Iterator for ReadDir {
                 // the size of dirent64. The file name is always a C string and terminated by `\0`.
                 // Consequently, we are able to ignore the last byte.
                 let name_bytes =
-                    unsafe { CStr::from_ptr(&dir.d_name as *const _ as *const i8).to_bytes() };
+                    unsafe { CStr::from_ptr(&dir.d_name as *const _ as *const c_char).to_bytes() };
                 let entry = DirEntry {
                     root: self.inner.root.clone(),
                     ino: dir.d_ino,
@@ -445,7 +445,7 @@ impl DirBuilder {
 
     pub fn mkdir(&self, path: &Path) -> io::Result<()> {
         run_path_with_cstr(path, &|path| {
-            cvt(unsafe { hermit_abi::mkdir(path.as_ptr(), self.mode.into()) }).map(|_| ())
+            cvt(unsafe { hermit_abi::mkdir(path.as_ptr().cast(), self.mode.into()) }).map(|_| ())
         })
     }
 
diff --git a/library/std/src/sys/pal/hermit/mod.rs b/library/std/src/sys/pal/hermit/mod.rs
index f03fca60344..d833c9d632c 100644
--- a/library/std/src/sys/pal/hermit/mod.rs
+++ b/library/std/src/sys/pal/hermit/mod.rs
@@ -85,7 +85,7 @@ pub unsafe extern "C" fn runtime_entry(
     }
 
     // initialize environment
-    os::init_environment(env as *const *const i8);
+    os::init_environment(env);
 
     let result = unsafe { main(argc as isize, argv) };
 
diff --git a/library/std/src/sys/pal/hermit/os.rs b/library/std/src/sys/pal/hermit/os.rs
index f8ea80afa43..791cdb1e57e 100644
--- a/library/std/src/sys/pal/hermit/os.rs
+++ b/library/std/src/sys/pal/hermit/os.rs
@@ -3,7 +3,7 @@ use core::slice::memchr;
 use super::hermit_abi;
 use crate::collections::HashMap;
 use crate::error::Error as StdError;
-use crate::ffi::{CStr, OsStr, OsString};
+use crate::ffi::{CStr, OsStr, OsString, c_char};
 use crate::marker::PhantomData;
 use crate::os::hermit::ffi::OsStringExt;
 use crate::path::{self, PathBuf};
@@ -70,7 +70,7 @@ pub fn current_exe() -> io::Result<PathBuf> {
 
 static ENV: Mutex<Option<HashMap<OsString, OsString>>> = Mutex::new(None);
 
-pub fn init_environment(env: *const *const i8) {
+pub fn init_environment(env: *const *const c_char) {
     let mut guard = ENV.lock().unwrap();
     let map = guard.insert(HashMap::new());
 
diff --git a/library/std/src/sys/pal/teeos/mod.rs b/library/std/src/sys/pal/teeos/mod.rs
index 2bf2e2ceb31..a9900f55b19 100644
--- a/library/std/src/sys/pal/teeos/mod.rs
+++ b/library/std/src/sys/pal/teeos/mod.rs
@@ -71,7 +71,7 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
         libc::ECONNREFUSED => ConnectionRefused,
         libc::ECONNRESET => ConnectionReset,
         libc::EDEADLK => Deadlock,
-        libc::EDQUOT => FilesystemQuotaExceeded,
+        libc::EDQUOT => QuotaExceeded,
         libc::EEXIST => AlreadyExists,
         libc::EFBIG => FileTooLarge,
         libc::EHOSTUNREACH => HostUnreachable,
diff --git a/library/std/src/sys/pal/unix/mod.rs b/library/std/src/sys/pal/unix/mod.rs
index 8eaa50d7f81..3cc1cae8d00 100644
--- a/library/std/src/sys/pal/unix/mod.rs
+++ b/library/std/src/sys/pal/unix/mod.rs
@@ -254,7 +254,7 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
         libc::ECONNREFUSED => ConnectionRefused,
         libc::ECONNRESET => ConnectionReset,
         libc::EDEADLK => Deadlock,
-        libc::EDQUOT => FilesystemQuotaExceeded,
+        libc::EDQUOT => QuotaExceeded,
         libc::EEXIST => AlreadyExists,
         libc::EFBIG => FileTooLarge,
         libc::EHOSTUNREACH => HostUnreachable,
diff --git a/library/std/src/sys/pal/unix/net.rs b/library/std/src/sys/pal/unix/net.rs
index d140607869c..d73b9fd5eb8 100644
--- a/library/std/src/sys/pal/unix/net.rs
+++ b/library/std/src/sys/pal/unix/net.rs
@@ -81,6 +81,7 @@ impl Socket {
                     target_os = "netbsd",
                     target_os = "openbsd",
                     target_os = "nto",
+                    target_os = "solaris",
                 ))] {
                     // On platforms that support it we pass the SOCK_CLOEXEC
                     // flag to atomically create the socket and set it as
diff --git a/library/std/src/sys/pal/wasi/fs.rs b/library/std/src/sys/pal/wasi/fs.rs
index 0667eb90101..7779d2b97d7 100644
--- a/library/std/src/sys/pal/wasi/fs.rs
+++ b/library/std/src/sys/pal/wasi/fs.rs
@@ -27,10 +27,27 @@ pub struct FileAttr {
 
 pub struct ReadDir {
     inner: Arc<ReadDirInner>,
-    cookie: Option<wasi::Dircookie>,
-    buf: Vec<u8>,
-    offset: usize,
-    cap: usize,
+    state: ReadDirState,
+}
+
+enum ReadDirState {
+    /// Fill `buf` with `buf.len()` bytes starting from `next_read_offset`.
+    FillBuffer {
+        next_read_offset: wasi::Dircookie,
+        buf: Vec<u8>,
+    },
+    ProcessEntry {
+        buf: Vec<u8>,
+        next_read_offset: Option<wasi::Dircookie>,
+        offset: usize,
+    },
+    /// There is no more data to get in [`Self::FillBuffer`]; keep returning
+    /// entries via ProcessEntry until `buf` is exhausted.
+    RunUntilExhaustion {
+        buf: Vec<u8>,
+        offset: usize,
+    },
+    Done,
 }
 
 struct ReadDirInner {
@@ -147,11 +164,8 @@ impl FileType {
 impl ReadDir {
     fn new(dir: File, root: PathBuf) -> ReadDir {
         ReadDir {
-            cookie: Some(0),
-            buf: vec![0; 128],
-            offset: 0,
-            cap: 0,
             inner: Arc::new(ReadDirInner { dir, root }),
+            state: ReadDirState::FillBuffer { next_read_offset: 0, buf: vec![0; 128] },
         }
     }
 }
@@ -162,78 +176,99 @@ impl fmt::Debug for ReadDir {
     }
 }
 
+impl core::iter::FusedIterator for ReadDir {}
+
 impl Iterator for ReadDir {
     type Item = io::Result<DirEntry>;
 
     fn next(&mut self) -> Option<io::Result<DirEntry>> {
-        loop {
-            // If we've reached the capacity of our buffer then we need to read
-            // some more from the OS, otherwise we pick up at our old offset.
-            let offset = if self.offset == self.cap {
-                let cookie = self.cookie.take()?;
-                match self.inner.dir.fd.readdir(&mut self.buf, cookie) {
-                    Ok(bytes) => self.cap = bytes,
-                    Err(e) => return Some(Err(e)),
-                }
-                self.offset = 0;
-                self.cookie = Some(cookie);
-
-                // If we didn't actually read anything, this is in theory the
-                // end of the directory.
-                if self.cap == 0 {
-                    self.cookie = None;
-                    return None;
-                }
-
-                0
-            } else {
-                self.offset
-            };
-            let data = &self.buf[offset..self.cap];
-
-            // If we're not able to read a directory entry then that means it
-            // must have been truncated at the end of the buffer, so reset our
-            // offset so we can go back and reread into the buffer, picking up
-            // where we last left off.
-            let dirent_size = mem::size_of::<wasi::Dirent>();
-            if data.len() < dirent_size {
-                assert!(self.cookie.is_some());
-                assert!(self.buf.len() >= dirent_size);
-                self.offset = self.cap;
-                continue;
-            }
-            let (dirent, data) = data.split_at(dirent_size);
-            let dirent = unsafe { ptr::read_unaligned(dirent.as_ptr() as *const wasi::Dirent) };
-
-            // If the file name was truncated, then we need to reinvoke
-            // `readdir` so we truncate our buffer to start over and reread this
-            // descriptor. Note that if our offset is 0 that means the file name
-            // is massive and we need a bigger buffer.
-            if data.len() < dirent.d_namlen as usize {
-                if offset == 0 {
-                    let amt_to_add = self.buf.capacity();
-                    self.buf.extend(iter::repeat(0).take(amt_to_add));
+        match &mut self.state {
+            ReadDirState::FillBuffer { next_read_offset, ref mut buf } => {
+                let result = self.inner.dir.fd.readdir(buf, *next_read_offset);
+                match result {
+                    Ok(read_bytes) => {
+                        if read_bytes < buf.len() {
+                            buf.truncate(read_bytes);
+                            self.state =
+                                ReadDirState::RunUntilExhaustion { buf: mem::take(buf), offset: 0 };
+                        } else {
+                            debug_assert_eq!(read_bytes, buf.len());
+                            self.state = ReadDirState::ProcessEntry {
+                                buf: mem::take(buf),
+                                offset: 0,
+                                next_read_offset: Some(*next_read_offset),
+                            };
+                        }
+                        self.next()
+                    }
+                    Err(e) => {
+                        self.state = ReadDirState::Done;
+                        return Some(Err(e));
+                    }
                 }
-                assert!(self.cookie.is_some());
-                self.offset = self.cap;
-                continue;
             }
-            self.cookie = Some(dirent.d_next);
-            self.offset = offset + dirent_size + dirent.d_namlen as usize;
+            ReadDirState::ProcessEntry { ref mut buf, next_read_offset, offset } => {
+                let contents = &buf[*offset..];
+                const DIRENT_SIZE: usize = crate::mem::size_of::<wasi::Dirent>();
+                if contents.len() >= DIRENT_SIZE {
+                    let (dirent, data) = contents.split_at(DIRENT_SIZE);
+                    let dirent =
+                        unsafe { ptr::read_unaligned(dirent.as_ptr() as *const wasi::Dirent) };
+                    // If the file name was truncated, then we need to reinvoke
+                    // `readdir` so we truncate our buffer to start over and reread this
+                    // descriptor.
+                    if data.len() < dirent.d_namlen as usize {
+                        if buf.len() < dirent.d_namlen as usize + DIRENT_SIZE {
+                            buf.resize(dirent.d_namlen as usize + DIRENT_SIZE, 0);
+                        }
+                        if let Some(next_read_offset) = *next_read_offset {
+                            self.state =
+                                ReadDirState::FillBuffer { next_read_offset, buf: mem::take(buf) };
+                        } else {
+                            self.state = ReadDirState::Done;
+                        }
+
+                        return self.next();
+                    }
+                    next_read_offset.as_mut().map(|cookie| {
+                        *cookie = dirent.d_next;
+                    });
+                    *offset = *offset + DIRENT_SIZE + dirent.d_namlen as usize;
 
-            let name = &data[..(dirent.d_namlen as usize)];
+                    let name = &data[..(dirent.d_namlen as usize)];
+
+                    // These names are skipped on all other platforms, so let's skip
+                    // them here too
+                    if name == b"." || name == b".." {
+                        return self.next();
+                    }
 
-            // These names are skipped on all other platforms, so let's skip
-            // them here too
-            if name == b"." || name == b".." {
-                continue;
+                    return Some(Ok(DirEntry {
+                        meta: dirent,
+                        name: name.to_vec(),
+                        inner: self.inner.clone(),
+                    }));
+                } else if let Some(next_read_offset) = *next_read_offset {
+                    self.state = ReadDirState::FillBuffer { next_read_offset, buf: mem::take(buf) };
+                } else {
+                    self.state = ReadDirState::Done;
+                }
+                self.next()
             }
+            ReadDirState::RunUntilExhaustion { buf, offset } => {
+                if *offset >= buf.len() {
+                    self.state = ReadDirState::Done;
+                } else {
+                    self.state = ReadDirState::ProcessEntry {
+                        buf: mem::take(buf),
+                        offset: *offset,
+                        next_read_offset: None,
+                    };
+                }
 
-            return Some(Ok(DirEntry {
-                meta: dirent,
-                name: name.to_vec(),
-                inner: self.inner.clone(),
-            }));
+                self.next()
+            }
+            ReadDirState::Done => None,
         }
     }
 }
diff --git a/library/std/src/sys/pal/windows/mod.rs b/library/std/src/sys/pal/windows/mod.rs
index d66ff15e10b..88e6def7a75 100644
--- a/library/std/src/sys/pal/windows/mod.rs
+++ b/library/std/src/sys/pal/windows/mod.rs
@@ -113,7 +113,7 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
         c::ERROR_WRITE_PROTECT => return ReadOnlyFilesystem,
         c::ERROR_DISK_FULL | c::ERROR_HANDLE_DISK_FULL => return StorageFull,
         c::ERROR_SEEK_ON_DEVICE => return NotSeekable,
-        c::ERROR_DISK_QUOTA_EXCEEDED => return FilesystemQuotaExceeded,
+        c::ERROR_DISK_QUOTA_EXCEEDED => return QuotaExceeded,
         c::ERROR_FILE_TOO_LARGE => return FileTooLarge,
         c::ERROR_BUSY => return ResourceBusy,
         c::ERROR_POSSIBLE_DEADLOCK => return Deadlock,
@@ -138,7 +138,7 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
         c::WSAEHOSTUNREACH => HostUnreachable,
         c::WSAENETDOWN => NetworkDown,
         c::WSAENETUNREACH => NetworkUnreachable,
-        c::WSAEDQUOT => FilesystemQuotaExceeded,
+        c::WSAEDQUOT => QuotaExceeded,
 
         _ => Uncategorized,
     }
diff --git a/library/std/src/sys/thread_local/key/unix.rs b/library/std/src/sys/thread_local/key/unix.rs
index 28e48a750b9..b4b58b34706 100644
--- a/library/std/src/sys/thread_local/key/unix.rs
+++ b/library/std/src/sys/thread_local/key/unix.rs
@@ -1,5 +1,25 @@
 use crate::mem;
 
+// For WASI add a few symbols not in upstream `libc` just yet.
+#[cfg(all(target_os = "wasi", target_env = "p1", target_feature = "atomics"))]
+mod libc {
+    use crate::ffi;
+
+    #[allow(non_camel_case_types)]
+    pub type pthread_key_t = ffi::c_uint;
+
+    extern "C" {
+        pub fn pthread_key_create(
+            key: *mut pthread_key_t,
+            destructor: unsafe extern "C" fn(*mut ffi::c_void),
+        ) -> ffi::c_int;
+        #[allow(dead_code)]
+        pub fn pthread_getspecific(key: pthread_key_t) -> *mut ffi::c_void;
+        pub fn pthread_setspecific(key: pthread_key_t, value: *const ffi::c_void) -> ffi::c_int;
+        pub fn pthread_key_delete(key: pthread_key_t) -> ffi::c_int;
+    }
+}
+
 pub type Key = libc::pthread_key_t;
 
 #[inline]
diff --git a/library/std/src/sys/thread_local/mod.rs b/library/std/src/sys/thread_local/mod.rs
index 31d3b439060..f0a13323ec9 100644
--- a/library/std/src/sys/thread_local/mod.rs
+++ b/library/std/src/sys/thread_local/mod.rs
@@ -86,7 +86,9 @@ pub(crate) mod guard {
             mod windows;
             pub(crate) use windows::enable;
         } else if #[cfg(any(
-            target_family = "wasm",
+            all(target_family = "wasm", not(
+                all(target_os = "wasi", target_env = "p1", target_feature = "atomics")
+            )),
             target_os = "uefi",
             target_os = "zkvm",
         ))] {
@@ -135,6 +137,7 @@ pub(crate) mod key {
                 target_family = "unix",
             ),
             target_os = "teeos",
+            all(target_os = "wasi", target_env = "p1", target_feature = "atomics"),
         ))] {
             mod racy;
             mod unix;
diff --git a/library/std/src/thread/local.rs b/library/std/src/thread/local.rs
index 56cf438bd9b..2313f4b5beb 100644
--- a/library/std/src/thread/local.rs
+++ b/library/std/src/thread/local.rs
@@ -12,7 +12,7 @@ use crate::cell::{Cell, RefCell};
 use crate::error::Error;
 use crate::fmt;
 
-/// A thread local storage key which owns its contents.
+/// A thread local storage (TLS) key which owns its contents.
 ///
 /// This key uses the fastest possible implementation available to it for the
 /// target platform. It is instantiated with the [`thread_local!`] macro and the