1 files changed, 26 insertions, 2 deletions

diff --git a/tokio/src/io/util/async_read_ext.rs b/tokio/src/io/util/async_read_ext.rs
index 0ab66c28..96a5f70d 100644
--- a/tokio/src/io/util/async_read_ext.rs
+++ b/tokio/src/io/util/async_read_ext.rs
@@ -1,6 +1,6 @@
 use crate::io::util::chain::{chain, Chain};
 use crate::io::util::read::{read, Read};
-use crate::io::util::read_buf::{read_buf, ReadBuf};
+use crate::io::util::read_buf::{poll_read_buf, read_buf, ReadBuf};
 use crate::io::util::read_exact::{read_exact, ReadExact};
 use crate::io::util::read_int::{
     ReadI128, ReadI128Le, ReadI16, ReadI16Le, ReadI32, ReadI32Le, ReadI64, ReadI64Le, ReadI8,
@@ -14,6 +14,8 @@ use crate::io::util::take::{take, Take};
 use crate::io::AsyncRead;
 
 use bytes::BufMut;
+use std::io;
+use std::task::{Context, Poll};
 
 cfg_io_util! {
     /// Defines numeric reader
@@ -185,7 +187,7 @@ cfg_io_util! {
         ///
         /// On a successful read, the number of read bytes is returned. If the
         /// supplied buffer is not empty and the function returns `Ok(0)` then
-        /// the source as reached an "end-of-file" event.
+        /// the source has reached an "end-of-file" event.
         ///
         /// # Errors
         ///
@@ -231,6 +233,28 @@ cfg_io_util! {
             read_buf(self, buf)
         }
 
+        /// Attempts to pull some bytes from this source into the specified buffer,
+        /// advancing the buffer's internal cursor if the underlying reader is ready.
+        ///
+        /// Usually, only a single `read` syscall is issued, even if there is
+        /// more space in the supplied buffer.
+        ///
+        /// # Return
+        ///
+        /// On a successful read, the number of read bytes is returned. If the
+        /// supplied buffer is not empty and the function returns `Ok(0)` then
+        /// the source has reached an "end-of-file" event.
+        ///
+        /// # Errors
+        ///
+        /// If this function encounters any form of I/O or other error, an error
+        /// variant will be returned. If an error is returned then it must be
+        /// guaranteed that no bytes were read.
+        /// ```
+        fn poll_read_buf<'a, B>(&'a mut self, buf: &'a mut B, cx: &mut Context<'_>) -> Poll<io::Result<usize>> where Self: Unpin + Sized, B: BufMut {
+            poll_read_buf(self, buf, cx)
+        }
+
         /// Reads the exact number of bytes required to fill `buf`.
         ///
         /// Equivalent to: