Clarify runtime shutdown method
@@ -297,8 +297,12 @@ pub trait Runtime: Send + Debug + 'static {
/// Notify the runtime that it has to shutdown.
///
- /// This callback is invoked before the node shutdown, so runtimes can stop themselves
- /// gracefully.
+ /// This callback is invoked sequentially for each runtime just before the node shutdown,
+ /// so runtimes can stop themselves gracefully.
+ ///
+ /// Invoking of this callback is guaranteed to be the last operation for the runtime.
+ /// Since this method is a part of shutdown process, runtimes can perform blocking and
+ /// heavy operations here if needed.
fn shutdown(&self) {}
}
