Rollup merge of rust-lang#110543 - joboet:reentrant_lock, r=m-ou-se

Make `ReentrantLock` public

Implements the ACP rust-lang/libs-team#193.

`@rustbot` label +T-libs-api +S-waiting-on-ACP

library/std/src/io/stdio.rs

@@ -11,8 +11,9 @@ use crate::fs::File;
 use crate::io::{
     self, BorrowedCursor, BufReader, IoSlice, IoSliceMut, LineWriter, Lines, SpecReadByte,
 };
+use crate::panic::{RefUnwindSafe, UnwindSafe};
 use crate::sync::atomic::{AtomicBool, Ordering};
-use crate::sync::{Arc, Mutex, MutexGuard, OnceLock, ReentrantMutex, ReentrantMutexGuard};
+use crate::sync::{Arc, Mutex, MutexGuard, OnceLock, ReentrantLock, ReentrantLockGuard};
 use crate::sys::stdio;
 
 type LocalStream = Arc<Mutex<Vec<u8>>>;
@@ -545,7 +546,7 @@ pub struct Stdout {
     // FIXME: this should be LineWriter or BufWriter depending on the state of
     //        stdout (tty or not). Note that if this is not line buffered it
     //        should also flush-on-panic or some form of flush-on-abort.
-    inner: &'static ReentrantMutex<RefCell<LineWriter<StdoutRaw>>>,
+    inner: &'static ReentrantLock<RefCell<LineWriter<StdoutRaw>>>,
 }
 
 /// A locked reference to the [`Stdout`] handle.
@@ -567,10 +568,10 @@ pub struct Stdout {
 #[must_use = "if unused stdout will immediately unlock"]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct StdoutLock<'a> {
-    inner: ReentrantMutexGuard<'a, RefCell<LineWriter<StdoutRaw>>>,
+    inner: ReentrantLockGuard<'a, RefCell<LineWriter<StdoutRaw>>>,
 }
 
-static STDOUT: OnceLock<ReentrantMutex<RefCell<LineWriter<StdoutRaw>>>> = OnceLock::new();
+static STDOUT: OnceLock<ReentrantLock<RefCell<LineWriter<StdoutRaw>>>> = OnceLock::new();
 
 /// Constructs a new handle to the standard output of the current process.
 ///
@@ -624,7 +625,7 @@ static STDOUT: OnceLock<ReentrantMutex<RefCell<LineWriter<StdoutRaw>>>> = OnceLo
 pub fn stdout() -> Stdout {
     Stdout {
         inner: STDOUT
-            .get_or_init(|| ReentrantMutex::new(RefCell::new(LineWriter::new(stdout_raw())))),
+            .get_or_init(|| ReentrantLock::new(RefCell::new(LineWriter::new(stdout_raw())))),
     }
 }
 
@@ -635,7 +636,7 @@ pub fn cleanup() {
     let mut initialized = false;
     let stdout = STDOUT.get_or_init(|| {
         initialized = true;
-        ReentrantMutex::new(RefCell::new(LineWriter::with_capacity(0, stdout_raw())))
+        ReentrantLock::new(RefCell::new(LineWriter::with_capacity(0, stdout_raw())))
     });
 
     if !initialized {
@@ -678,6 +679,12 @@ impl Stdout {
     }
 }
 
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl UnwindSafe for Stdout {}
+
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl RefUnwindSafe for Stdout {}
+
 #[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Stdout {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -737,6 +744,12 @@ impl Write for &Stdout {
     }
 }
 
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl UnwindSafe for StdoutLock<'_> {}
+
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl RefUnwindSafe for StdoutLock<'_> {}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Write for StdoutLock<'_> {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
@@ -786,7 +799,7 @@ impl fmt::Debug for StdoutLock<'_> {
 /// standard library or via raw Windows API calls, will fail.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct Stderr {
-    inner: &'static ReentrantMutex<RefCell<StderrRaw>>,
+    inner: &'static ReentrantLock<RefCell<StderrRaw>>,
 }
 
 /// A locked reference to the [`Stderr`] handle.
@@ -808,7 +821,7 @@ pub struct Stderr {
 #[must_use = "if unused stderr will immediately unlock"]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct StderrLock<'a> {
-    inner: ReentrantMutexGuard<'a, RefCell<StderrRaw>>,
+    inner: ReentrantLockGuard<'a, RefCell<StderrRaw>>,
 }
 
 /// Constructs a new handle to the standard error of the current process.
@@ -862,8 +875,8 @@ pub fn stderr() -> Stderr {
     // Note that unlike `stdout()` we don't use `at_exit` here to register a
     // destructor. Stderr is not buffered, so there's no need to run a
     // destructor for flushing the buffer
-    static INSTANCE: ReentrantMutex<RefCell<StderrRaw>> =
-        ReentrantMutex::new(RefCell::new(stderr_raw()));
+    static INSTANCE: ReentrantLock<RefCell<StderrRaw>> =
+        ReentrantLock::new(RefCell::new(stderr_raw()));
 
     Stderr { inner: &INSTANCE }
 }
@@ -898,6 +911,12 @@ impl Stderr {
     }
 }
 
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl UnwindSafe for Stderr {}
+
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl RefUnwindSafe for Stderr {}
+
 #[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Stderr {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -957,6 +976,12 @@ impl Write for &Stderr {
     }
 }
 
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl UnwindSafe for StderrLock<'_> {}
+
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl RefUnwindSafe for StderrLock<'_> {}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Write for StderrLock<'_> {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {

library/std/src/sync/mod.rs

@@ -184,7 +184,8 @@ pub use self::lazy_lock::LazyLock;
 #[stable(feature = "once_cell", since = "1.70.0")]
 pub use self::once_lock::OnceLock;
 
-pub(crate) use self::remutex::{ReentrantMutex, ReentrantMutexGuard};
+#[unstable(feature = "reentrant_lock", issue = "121440")]
+pub use self::reentrant_lock::{ReentrantLock, ReentrantLockGuard};
 
 pub mod mpsc;
 
@@ -196,5 +197,5 @@ mod mutex;
 pub(crate) mod once;
 mod once_lock;
 mod poison;
-mod remutex;
+mod reentrant_lock;
 mod rwlock;