From 3e87558e5d279a0a3a6d78fef8f154bc2e5a037f Mon Sep 17 00:00:00 2001
From: Yifan Wu <shinbokuow@163.com>
Date: Mon, 19 Jul 2021 23:50:34 +0800
Subject: [PATCH] Add comment.

---
 os/src/batch.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/os/src/batch.rs b/os/src/batch.rs
index f2a0d649..816e8b78 100644
--- a/os/src/batch.rs
+++ b/os/src/batch.rs
@@ -116,6 +116,8 @@ pub fn run_next_app() -> ! {
     }
     app_manager.move_to_next_app();
     drop(app_manager);
+    // before this we have to drop local variables related to resources manually
+    // and release the resources
     extern "C" { fn __restore(cx_addr: usize); }
     unsafe {
         __restore(KERNEL_STACK.push_context(