std: Doc blocking behavior of LazyLock

Author: behnam-oneschema

library/std/src/sync/lazy_lock.rs

@@ -134,9 +134,11 @@ impl<T, F: FnOnce() -> T> LazyLock<T, F> {
         }
     }
 
-    /// Forces the evaluation of this lazy value and
-    /// returns a reference to result. This is equivalent
-    /// to the `Deref` impl, but is explicit.
+    /// Forces the evaluation of this lazy value and returns a reference to
+    /// result. This is equivalent to the `Deref` impl, but is explicit.
+    ///
+    /// This method will block the calling thread if another initialization
+    /// routine is currently running.
     ///
     /// # Examples
     ///
@@ -204,6 +206,11 @@ impl<T, F> Drop for LazyLock<T, F> {
 impl<T, F: FnOnce() -> T> Deref for LazyLock<T, F> {
     type Target = T;
 
+    /// Dereferences the value.
+    ///
+    /// This method will block the calling thread if another initialization
+    /// routine is currently running.
+    ///
     #[inline]
     fn deref(&self) -> &T {
         LazyLock::force(self)