Adds MtxLock

Author: ultimaweapon

src/lock/mod.rs

@@ -7,3 +7,24 @@ pub trait LockObject: Sized {}
 pub trait Mtx<K: Kernel>: Sized {
     fn lock_mut(&mut self) -> &mut K::LockObject;
 }
+
+/// RAII struct to unlock a mutex when dropped.
+pub struct MtxLock<K: Kernel> {
+    kern: K,
+    mtx: *mut K::Mtx,
+}
+
+impl<K: Kernel> MtxLock<K> {
+    /// # Safety
+    /// `mtx` cannot be null.
+    pub unsafe fn new(kern: K, mtx: *mut K::Mtx) -> Self {
+        kern.mtx_lock_flags(mtx, 0, c"".as_ptr(), 0);
+        Self { kern, mtx }
+    }
+}
+
+impl<K: Kernel> Drop for MtxLock<K> {
+    fn drop(&mut self) {
+        unsafe { self.kern.mtx_unlock_flags(self.mtx, 0, c"".as_ptr(), 0) };
+    }
+}