Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/third_party/rust/tokio/src/util/slab/slot.rs b/third_party/rust/tokio/src/util/slab/slot.rs
new file mode 100644
index 0000000000..0608b26189
--- /dev/null
+++ b/third_party/rust/tokio/src/util/slab/slot.rs
@@ -0,0 +1,42 @@
+use crate::loom::cell::UnsafeCell;
+use crate::util::slab::{Entry, Generation};
+
+/// Stores an entry in the slab.
+pub(super) struct Slot<T> {
+    next: UnsafeCell<usize>,
+    entry: T,
+}
+
+impl<T: Entry> Slot<T> {
+    /// Initialize a new `Slot` linked to `next`.
+    ///
+    /// The entry is initialized to a default value.
+    pub(super) fn new(next: usize) -> Slot<T> {
+        Slot {
+            next: UnsafeCell::new(next),
+            entry: T::default(),
+        }
+    }
+
+    pub(super) fn get(&self) -> &T {
+        &self.entry
+    }
+
+    pub(super) fn generation(&self) -> Generation {
+        self.entry.generation()
+    }
+
+    pub(super) fn reset(&self, generation: Generation) -> bool {
+        self.entry.reset(generation)
+    }
+
+    pub(super) fn next(&self) -> usize {
+        self.next.with(|next| unsafe { *next })
+    }
+
+    pub(super) fn set_next(&self, next: usize) {
+        self.next.with_mut(|n| unsafe {
+            (*n) = next;
+        })
+    }
+}