From 3ba818a177a34dabd38c01a7a1aa15a5bc867c1f Mon Sep 17 00:00:00 2001
From: Boqin Qin <bobbqqin@bupt.edu.cn>
Date: Tue, 12 May 2020 03:59:46 +0800
Subject: [PATCH] io: add doc warning about concurrently calling
 poll_read/write_ready (#2439)

Co-authored-by: Alice Ryhl <alice@ryhl.io>
Fixes: #2429
---
 tokio/src/io/poll_evented.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tokio/src/io/poll_evented.rs b/tokio/src/io/poll_evented.rs
index 085a7e842da..f8be6f2f755 100644
--- a/tokio/src/io/poll_evented.rs
+++ b/tokio/src/io/poll_evented.rs
@@ -261,6 +261,11 @@ where
     ///
     /// * `ready` includes writable.
     /// * called from outside of a task context.
+    ///
+    /// # Warning
+    ///
+    /// This method may not be called concurrently. It takes `&self` to allow
+    /// calling it concurrently with `poll_write_ready`.
     pub fn poll_read_ready(
         &self,
         cx: &mut Context<'_>,
@@ -327,6 +332,11 @@ where
     ///
     /// * `ready` contains bits besides `writable` and `hup`.
     /// * called from outside of a task context.
+    ///
+    /// # Warning
+    ///
+    /// This method may not be called concurrently. It takes `&self` to allow
+    /// calling it concurrently with `poll_read_ready`.
     pub fn poll_write_ready(&self, cx: &mut Context<'_>) -> Poll<io::Result<mio::Ready>> {
         poll_ready!(
             self,