From bb99d33fb02a716654c3fd84361c799f838a7d6a Mon Sep 17 00:00:00 2001
From: Abutalib Aghayev <agayev@psu.edu>
Date: Thu, 27 Oct 2022 15:55:51 -0400
Subject: [PATCH] rt: add a method to determine if the runtime is
 multi-threaded.

---
 tokio/src/runtime/handle.rs | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/tokio/src/runtime/handle.rs b/tokio/src/runtime/handle.rs
index 91974252610..07150927f8f 100644
--- a/tokio/src/runtime/handle.rs
+++ b/tokio/src/runtime/handle.rs
@@ -101,6 +101,33 @@ impl Handle {
         }
     }
 
+    /// Returns true if the current `Runtime` is multi-threaded and false
+    /// otherwise.
+    ///
+    /// ```
+    /// use tokio::runtime::Handle;
+    ///
+    /// #[tokio::main(flavor = "current_thread")]
+    /// async fn main() {
+    ///   assert!(!Handle::current().is_multi_threaded());
+    /// }
+    /// ```
+    ///
+    /// ```
+    /// use tokio::runtime::Handle;
+    ///
+    /// #[tokio::main(flavor = "multi_thread", worker_threads = 4)]
+    /// async fn main() {
+    ///   assert!(Handle::current().is_multi_threaded());
+    /// }
+    /// ```
+    pub fn is_multi_threaded(&self) -> bool {
+        match self.inner {
+            scheduler::Handle::CurrentThread(_) => false,
+            scheduler::Handle::MultiThread(_) => true,
+        }
+    }
+
     /// Returns a Handle view over the currently running Runtime
     ///
     /// Returns an error if no Runtime has been started