Loosen Send/Sync bounds on futures

This ensures that `Send`/`Sync` bounds for each future match those of the value produed by the future.
smol-rs · Jun 1, 2023 · 76430c6 · 76430c6
1 parent 90b1a30
commit 76430c6
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Showing 2 changed files with 14 additions and 5 deletions.
diff --git a/src/mutex.rs b/src/mutex.rs
@@ -268,6 +268,9 @@ pub struct Lock<'a, T: ?Sized> {
     acquire_slow: Option<AcquireSlow<&'a Mutex<T>, T>>,
 }
 
+unsafe impl<T: Send + ?Sized> Send for Lock<'_, T> {}
+unsafe impl<T: Sync + ?Sized> Sync for Lock<'_, T> {}
+
 impl<'a, T: ?Sized> Unpin for Lock<'a, T> {}
 
 impl<T: ?Sized> fmt::Debug for Lock<'_, T> {
@@ -319,6 +322,9 @@ enum LockArcInnards<T: ?Sized> {
     Empty,
 }
 
+unsafe impl<T: Send + ?Sized> Send for LockArc<T> {}
+unsafe impl<T: Sync + ?Sized> Sync for LockArc<T> {}
+
 impl<T: ?Sized> Unpin for LockArc<T> {}
 
 impl<T: ?Sized> fmt::Debug for LockArc<T> {

diff --git a/src/rwlock.rs b/src/rwlock.rs
@@ -324,8 +324,8 @@ pub struct Read<'a, T: ?Sized> {
     value: *const T,
 }
 
-unsafe impl<T: Send + Sync + ?Sized> Send for Read<'_, T> {}
-unsafe impl<T: Send + Sync + ?Sized> Sync for Read<'_, T> {}
+unsafe impl<T: Sync + ?Sized> Send for Read<'_, T> {}
+unsafe impl<T: Sync + ?Sized> Sync for Read<'_, T> {}
 
 impl<T: ?Sized> fmt::Debug for Read<'_, T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -360,7 +360,7 @@ pub struct UpgradableRead<'a, T: ?Sized> {
 }
 
 unsafe impl<T: Send + Sync + ?Sized> Send for UpgradableRead<'_, T> {}
-unsafe impl<T: Send + Sync + ?Sized> Sync for UpgradableRead<'_, T> {}
+unsafe impl<T: Sync + ?Sized> Sync for UpgradableRead<'_, T> {}
 
 impl<T: ?Sized> fmt::Debug for UpgradableRead<'_, T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -393,8 +393,8 @@ pub struct Write<'a, T: ?Sized> {
     value: *mut T,
 }
 
-unsafe impl<T: Send + Sync + ?Sized> Send for Write<'_, T> {}
-unsafe impl<T: Send + Sync + ?Sized> Sync for Write<'_, T> {}
+unsafe impl<T: Send + ?Sized> Send for Write<'_, T> {}
+unsafe impl<T: Sync + ?Sized> Sync for Write<'_, T> {}
 
 impl<T: ?Sized> fmt::Debug for Write<'_, T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -623,6 +623,9 @@ pub struct Upgrade<'a, T: ?Sized> {
     value: *mut T,
 }
 
+unsafe impl<T: Send + ?Sized> Send for Upgrade<'_, T> {}
+unsafe impl<T: Sync + ?Sized> Sync for Upgrade<'_, T> {}
+
 impl<T: ?Sized> fmt::Debug for Upgrade<'_, T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Upgrade").finish()