From a8a4a9f0fceb33162bfb34160ac8ceb098c65ee3 Mon Sep 17 00:00:00 2001
From: Carl Lerche <me@carllerche.com>
Date: Sun, 1 Dec 2019 12:58:01 -0800
Subject: [PATCH] blocking: fix `spawn_blocking` after shutdown (#1875)

The task handle needs to be shutdown explicitly and not dropped.

Closes #1853
---
 tokio/src/runtime/blocking/pool.rs |  3 +++
 tokio/tests/rt_common.rs           | 19 ++++++++++++++++++-
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/tokio/src/runtime/blocking/pool.rs b/tokio/src/runtime/blocking/pool.rs
index 052d361ad..3e7d401bf 100644
--- a/tokio/src/runtime/blocking/pool.rs
+++ b/tokio/src/runtime/blocking/pool.rs
@@ -197,6 +197,9 @@ impl Spawner {
             let mut shared = self.inner.shared.lock().unwrap();
 
             if shared.shutdown {
+                // Shutdown the task
+                task.shutdown();
+
                 // no need to even push this task; it would never get picked up
                 return;
             }
diff --git a/tokio/tests/rt_common.rs b/tokio/tests/rt_common.rs
index a3b68f1c7..06c966bfe 100644
--- a/tokio/tests/rt_common.rs
+++ b/tokio/tests/rt_common.rs
@@ -44,7 +44,7 @@ rt_test! {
     use tokio::prelude::*;
     use tokio::runtime::Runtime;
     use tokio::sync::oneshot;
-    use tokio::time;
+    use tokio::{task, time};
     use tokio_test::{assert_err, assert_ok};
 
     use futures::future::poll_fn;
@@ -438,6 +438,23 @@ rt_test! {
         });
     }
 
+    #[test]
+    fn spawn_blocking_after_shutdown() {
+        let rt = rt();
+        let handle = rt.handle().clone();
+
+        // Shutdown
+        drop(rt);
+
+        handle.enter(|| {
+            let res = task::spawn_blocking(|| unreachable!());
+
+            // Avoid using a tokio runtime
+            let out = futures::executor::block_on(res);
+            assert!(out.is_err());
+        });
+    }
+
     #[test]
     fn io_driver_called_when_under_load() {
         let mut rt = rt();