1 files changed, 69 insertions, 0 deletions
diff --git a/src/rwlock/write_guard.rs b/src/rwlock/write_guard.rs
new file mode 100644
index 0000000..8f5feb4
--- /dev/null
+++ b/src/rwlock/write_guard.rs
@@ -0,0 +1,69 @@
+use std::marker::PhantomData;
+use std::ops::{Deref, DerefMut};
+
+use lock_api::RawRwLock;
+
+use crate::key::Keyable;
+
+use super::{RwLock, RwLockWriteGuard, RwLockWriteRef};
+
+impl<'a, T: ?Sized + 'a, R: RawRwLock> Deref for RwLockWriteRef<'a, T, R> {
+	type Target = T;
+
+	fn deref(&self) -> &Self::Target {
+		// safety: this is the only type that can use `value`, and there's
+		//         a reference to this type, so there cannot be any mutable
+		//         references to this value.
+		unsafe { &*self.0.value.get() }
+	}
+}
+
+impl<'a, T: ?Sized + 'a, R: RawRwLock> DerefMut for RwLockWriteRef<'a, T, R> {
+	fn deref_mut(&mut self) -> &mut Self::Target {
+		// safety: this is the only type that can use `value`, and we have a
+		//         mutable reference to this type, so there cannot be any other
+		//         references to this value.
+		unsafe { &mut *self.0.value.get() }
+	}
+}
+
+impl<'a, T: ?Sized + 'a, R: RawRwLock> Drop for RwLockWriteRef<'a, T, R> {
+	fn drop(&mut self) {
+		// safety: this guard is being destroyed, so the data cannot be
+		//         accessed without locking again
+		unsafe { self.0.force_unlock_write() }
+	}
+}
+
+impl<'a, 'key: 'a, T: ?Sized + 'a, Key: Keyable, R: RawRwLock> Deref
+	for RwLockWriteGuard<'a, 'key, T, Key, R>
+{
+	type Target = T;
+
+	fn deref(&self) -> &Self::Target {
+		&self.rwlock
+	}
+}
+
+impl<'a, 'key: 'a, T: ?Sized + 'a, Key: Keyable, R: RawRwLock> DerefMut
+	for RwLockWriteGuard<'a, 'key, T, Key, R>
+{
+	fn deref_mut(&mut self) -> &mut Self::Target {
+		&mut self.rwlock
+	}
+}
+
+impl<'a, 'key: 'a, T: ?Sized + 'a, Key: Keyable, R: RawRwLock>
+	RwLockWriteGuard<'a, 'key, T, Key, R>
+{
+	/// Create a guard to the given mutex. Undefined if multiple guards to the
+	/// same mutex exist at once.
+	#[must_use]
+	pub(super) const unsafe fn new(rwlock: &'a RwLock<T, R>, thread_key: Key) -> Self {
+		Self {
+			rwlock: RwLockWriteRef(rwlock),
+			thread_key,
+			_phantom: PhantomData,
+		}
+	}
+}