Rollup merge of rust-lang#98555 - mkroening:hermit-lock-init, r=m-ou-se

Hermit: Fix initializing lazy locks

Closes hermit-os/hermit-rs#322.

The initialization function of hermit's `Condvar` is not called since rust-lang#97647 and was erroneously removed in rust-lang#97879.

r? `@m-ou-se`

CC: `@stlankes`

Author: Dylan-DPC

library/std/src/sys/hermit/condvar.rs

@@ -3,6 +3,7 @@ use crate::ptr;
 use crate::sync::atomic::{AtomicUsize, Ordering::SeqCst};
 use crate::sys::hermit::abi;
 use crate::sys::locks::Mutex;
+use crate::sys_common::lazy_box::{LazyBox, LazyInit};
 use crate::time::Duration;
 
 // The implementation is inspired by Andrew D. Birrell's paper
@@ -14,14 +15,26 @@ pub struct Condvar {
     sem2: *const c_void,
 }
 
-pub type MovableCondvar = Condvar;
+pub(crate) type MovableCondvar = LazyBox<Condvar>;
+
+impl LazyInit for Condvar {
+    fn init() -> Box<Self> {
+        Box::new(Self::new())
+    }
+}
 
 unsafe impl Send for Condvar {}
 unsafe impl Sync for Condvar {}
 
 impl Condvar {
-    pub const fn new() -> Condvar {
-        Condvar { counter: AtomicUsize::new(0), sem1: ptr::null(), sem2: ptr::null() }
+    pub fn new() -> Self {
+        let mut condvar =
+            Self { counter: AtomicUsize::new(0), sem1: ptr::null(), sem2: ptr::null() };
+        unsafe {
+            let _ = abi::sem_init(&mut condvar.sem1, 0);
+            let _ = abi::sem_init(&mut condvar.sem2, 0);
+        }
+        condvar
     }
 
     pub unsafe fn notify_one(&self) {

library/std/src/sys/hermit/mutex.rs

@@ -175,9 +175,7 @@ impl Mutex {
     }
 
     #[inline]
-    pub unsafe fn init(&mut self) {
-        self.inner = Spinlock::new(MutexInner::new());
-    }
+    pub unsafe fn init(&mut self) {}
 
     #[inline]
     pub unsafe fn lock(&self) {

library/std/src/sys/hermit/rwlock.rs

@@ -1,9 +1,10 @@
 use crate::cell::UnsafeCell;
-use crate::sys::locks::{Condvar, Mutex};
+use crate::sys::locks::{MovableCondvar, Mutex};
+use crate::sys_common::lazy_box::{LazyBox, LazyInit};
 
 pub struct RwLock {
     lock: Mutex,
-    cond: Condvar,
+    cond: MovableCondvar,
     state: UnsafeCell<State>,
 }
 
@@ -28,7 +29,11 @@ unsafe impl Sync for RwLock {}
 
 impl RwLock {
     pub const fn new() -> RwLock {
-        RwLock { lock: Mutex::new(), cond: Condvar::new(), state: UnsafeCell::new(State::Unlocked) }
+        RwLock {
+            lock: Mutex::new(),
+            cond: MovableCondvar::new(),
+            state: UnsafeCell::new(State::Unlocked),
+        }
     }
 
     #[inline]