From a87f5ca917b5c3c10163601da74df2045ee8e6ea Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sun, 13 Oct 2024 12:34:28 +0200
Subject: sys/unix: add comments for some Miri fallbacks

---
 library/std/src/sys/sync/thread_parking/mod.rs | 1 +
 1 file changed, 1 insertion(+)

(limited to 'library/std/src/sys/sync')

diff --git a/library/std/src/sys/sync/thread_parking/mod.rs b/library/std/src/sys/sync/thread_parking/mod.rs
index 0ebc5e093ee..f4d8fa0a58c 100644
--- a/library/std/src/sys/sync/thread_parking/mod.rs
+++ b/library/std/src/sys/sync/thread_parking/mod.rs
@@ -23,6 +23,7 @@ cfg_if::cfg_if! {
         mod windows7;
         pub use windows7::Parker;
     } else if #[cfg(all(target_vendor = "apple", not(miri)))] {
+        // Doesn't work in Miri, see <https://github.com/rust-lang/miri/issues/2589>.
         mod darwin;
         pub use darwin::Parker;
     } else if #[cfg(target_os = "xous")] {
-- 
cgit 1.4.1-3-g733a5


From 937d13b8efc43f3f2e93f81360565d82f243ce15 Mon Sep 17 00:00:00 2001
From: Slanterns <slanterns.w@gmail.com>
Date: Wed, 16 Oct 2024 00:22:05 +0800
Subject: relax a memory order in `once_box`

---
 library/std/src/sys/sync/once_box.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'library/std/src/sys/sync')

diff --git a/library/std/src/sys/sync/once_box.rs b/library/std/src/sys/sync/once_box.rs
index 1422b5a1721..9d24db2245a 100644
--- a/library/std/src/sys/sync/once_box.rs
+++ b/library/std/src/sys/sync/once_box.rs
@@ -8,7 +8,7 @@
 use crate::mem::replace;
 use crate::ptr::null_mut;
 use crate::sync::atomic::AtomicPtr;
-use crate::sync::atomic::Ordering::{AcqRel, Acquire, Relaxed};
+use crate::sync::atomic::Ordering::{Acquire, Relaxed, Release};
 
 pub(crate) struct OnceBox<T> {
     ptr: AtomicPtr<T>,
@@ -60,7 +60,7 @@ impl<T> OnceBox<T> {
     #[cold]
     fn initialize(&self, f: impl FnOnce() -> Box<T>) -> &T {
         let new_ptr = Box::into_raw(f());
-        match self.ptr.compare_exchange(null_mut(), new_ptr, AcqRel, Acquire) {
+        match self.ptr.compare_exchange(null_mut(), new_ptr, Release, Acquire) {
             Ok(_) => unsafe { &*new_ptr },
             Err(ptr) => {
                 // Lost the race to another thread.
-- 
cgit 1.4.1-3-g733a5