From a8b75dbdf4360c9fd7fb874022169f0c00d38c4a Mon Sep 17 00:00:00 2001
From: Matthew Ahrens <matthew.ahrens@delphix.com>
Date: Fri, 25 Mar 2022 12:16:47 -0700
Subject: [PATCH] sync: add `watch::Receiver::same_channel` (#4581)

---
 tokio/src/sync/watch.rs | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tokio/src/sync/watch.rs b/tokio/src/sync/watch.rs
index ab0ada7d0..42be67613 100644
--- a/tokio/src/sync/watch.rs
+++ b/tokio/src/sync/watch.rs
@@ -467,6 +467,22 @@ impl<T> Receiver<T> {
         }
     }
 
+    /// Returns `true` if receivers belong to the same channel.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let (tx, rx) = tokio::sync::watch::channel(true);
+    /// let rx2 = rx.clone();
+    /// assert!(rx.same_channel(&rx2));
+    ///
+    /// let (tx3, rx3) = tokio::sync::watch::channel(true);
+    /// assert!(!rx3.same_channel(&rx2));
+    /// ```
+    pub fn same_channel(&self, other: &Self) -> bool {
+        Arc::ptr_eq(&self.shared, &other.shared)
+    }
+
     cfg_process_driver! {
         pub(crate) fn try_has_changed(&mut self) -> Option<Result<(), error::RecvError>> {
             maybe_changed(&self.shared, &mut self.version)