Merging upstream version 1.70.0+dfsg2.

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

1 files changed, 69 insertions, 0 deletions

diff --git a/vendor/im-rc/src/sync.rs b/vendor/im-rc/src/sync.rs
new file mode 100644
index 000000000..9b137555e
--- /dev/null
+++ b/vendor/im-rc/src/sync.rs
@@ -0,0 +1,69 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+pub(crate) use self::lock::Lock;
+
+#[cfg(threadsafe)]
+mod lock {
+    use std::sync::{Arc, Mutex, MutexGuard};
+
+    /// Thread safe lock: just wraps a `Mutex`.
+    pub(crate) struct Lock<A> {
+        lock: Arc<Mutex<A>>,
+    }
+
+    impl<A> Lock<A> {
+        pub(crate) fn new(value: A) -> Self {
+            Lock {
+                lock: Arc::new(Mutex::new(value)),
+            }
+        }
+
+        #[inline]
+        pub(crate) fn lock(&mut self) -> Option<MutexGuard<'_, A>> {
+            self.lock.lock().ok()
+        }
+    }
+
+    impl<A> Clone for Lock<A> {
+        fn clone(&self) -> Self {
+            Lock {
+                lock: self.lock.clone(),
+            }
+        }
+    }
+}
+
+#[cfg(not(threadsafe))]
+mod lock {
+    use std::cell::{RefCell, RefMut};
+    use std::rc::Rc;
+
+    /// Single threaded lock: a `RefCell` so we should safely panic if somehow
+    /// trying to access the stored data twice from the same thread.
+    pub(crate) struct Lock<A> {
+        lock: Rc<RefCell<A>>,
+    }
+
+    impl<A> Lock<A> {
+        pub(crate) fn new(value: A) -> Self {
+            Lock {
+                lock: Rc::new(RefCell::new(value)),
+            }
+        }
+
+        #[inline]
+        pub(crate) fn lock(&mut self) -> Option<RefMut<'_, A>> {
+            self.lock.try_borrow_mut().ok()
+        }
+    }
+
+    impl<A> Clone for Lock<A> {
+        fn clone(&self) -> Self {
+            Lock {
+                lock: self.lock.clone(),
+            }
+        }
+    }
+}