Auto merge of #103150 - joboet:remove_lock_wrappers, r=m-ou-se

Remove lock wrappers in `sys_common`

This moves the lazy allocation to `sys` (SGX and UNIX). While this leads to a bit more verbosity, it will simplify future improvements by making room in `sys_common` for platform-independent implementations.

This also removes the condvar check on SGX as it is not necessary for soundness and will be removed anyway once mutex has been made movable.

For simplicity's sake, `libunwind` also uses lazy allocation now on SGX. This will require an update to the C definitions before merging this (CC `@raoulstrackx).`

r? `@m-ou-se`

1 files changed, 12 insertions, 12 deletions

diff --git a/library/std/src/sys/sgx/mutex.rs b/library/std/src/sys/sgx/mutex.rs
index aa747d56b0d..0dbf020ebe0 100644
--- a/library/std/src/sys/sgx/mutex.rs
+++ b/library/std/src/sys/sgx/mutex.rs
@@ -1,28 +1,28 @@
 use super::waitqueue::{try_lock_or_false, SpinMutex, WaitQueue, WaitVariable};
 use crate::sys_common::lazy_box::{LazyBox, LazyInit};
 
+/// FIXME: `UnsafeList` is not movable.
+struct AllocatedMutex(SpinMutex<WaitVariable<bool>>);
+
 pub struct Mutex {
-    inner: SpinMutex<WaitVariable<bool>>,
+    inner: LazyBox<AllocatedMutex>,
 }
 
-// not movable: see UnsafeList implementation
-pub(crate) type MovableMutex = LazyBox<Mutex>;
-
-impl LazyInit for Mutex {
+impl LazyInit for AllocatedMutex {
     fn init() -> Box<Self> {
-        Box::new(Self::new())
+        Box::new(AllocatedMutex(SpinMutex::new(WaitVariable::new(false))))
     }
 }
 
 // Implementation according to “Operating Systems: Three Easy Pieces”, chapter 28
 impl Mutex {
     pub const fn new() -> Mutex {
-        Mutex { inner: SpinMutex::new(WaitVariable::new(false)) }
+        Mutex { inner: LazyBox::new() }
     }
 
     #[inline]
-    pub unsafe fn lock(&self) {
-        let mut guard = self.inner.lock();
+    pub fn lock(&self) {
+        let mut guard = self.inner.0.lock();
         if *guard.lock_var() {
             // Another thread has the lock, wait
             WaitQueue::wait(guard, || {})
@@ -35,7 +35,7 @@ impl Mutex {
 
     #[inline]
     pub unsafe fn unlock(&self) {
-        let guard = self.inner.lock();
+        let guard = self.inner.0.lock();
         if let Err(mut guard) = WaitQueue::notify_one(guard) {
             // No other waiters, unlock
             *guard.lock_var_mut() = false;
@@ -45,8 +45,8 @@ impl Mutex {
     }
 
     #[inline]
-    pub unsafe fn try_lock(&self) -> bool {
-        let mut guard = try_lock_or_false!(self.inner);
+    pub fn try_lock(&self) -> bool {
+        let mut guard = try_lock_or_false!(self.inner.0);
         if *guard.lock_var() {
             // Another thread has the lock
             false