From 1b17e4607dd159e634243d44d2d2fc832d390372 Mon Sep 17 00:00:00 2001
From: Henry Robinson <hrobinson@slack-corp.com>
Date: Fri, 15 Jul 2022 10:49:24 -0700
Subject: [PATCH] Test: recycle server reader buffers

Signed-off-by: Henry Robinson <hrobinson@slack-corp.com>
---
 go/mysql/conn.go   | 11 ++++++++++-
 go/mysql/server.go |  2 ++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/go/mysql/conn.go b/go/mysql/conn.go
index edb1201afe3..63eb0279349 100644
--- a/go/mysql/conn.go
+++ b/go/mysql/conn.go
@@ -228,6 +228,8 @@ func newConn(conn net.Conn) *Conn {
 	}
 }
 
+var readersPool = sync.Pool{New: func() interface{} { return bufio.NewReaderSize(nil, 16*1024) }}
+
 // newServerConn should be used to create server connections.
 //
 // It stashes a reference to the listener to be able to determine if
@@ -241,11 +243,18 @@ func newServerConn(conn net.Conn, listener *Listener) *Conn {
 		PrepareData: make(map[uint32]*PrepareData),
 	}
 	if listener.connReadBufferSize > 0 {
-		c.bufferedReader = bufio.NewReaderSize(conn, listener.connReadBufferSize)
+		buf := readersPool.Get().(*bufio.Reader)
+		buf.Reset(conn)
+		c.bufferedReader = buf
 	}
 	return c
 }
 
+func (c *Conn) returnReader() {
+	c.bufferedReader.Reset(nil)
+	readersPool.Put(c.bufferedReader)
+}
+
 // startWriterBuffering starts using buffered writes. This should
 // be terminated by a call to endWriteBuffering.
 func (c *Conn) startWriterBuffering() {
diff --git a/go/mysql/server.go b/go/mysql/server.go
index e6de1925974..6dd9b9f6d0d 100644
--- a/go/mysql/server.go
+++ b/go/mysql/server.go
@@ -306,6 +306,8 @@ func (l *Listener) handle(conn net.Conn, connectionID uint32, acceptTime time.Ti
 		// startWriterBuffering is called
 		c.endWriterBuffering()
 
+		c.returnReader()
+
 		conn.Close()
 	}()