From 7a375a492c08deee6ead242e03f4ecd694598993 Mon Sep 17 00:00:00 2001
From: Norman Maurer <norman_maurer@apple.com>
Date: Fri, 16 Aug 2019 09:27:47 +0200
Subject: [PATCH] HTTP2: Update local flow-controller on Channel.read() if
 needed (#9400)

Motivation:

We should better update the flow-controller on Channel.read() to reduce overhead and memory overhead.

See https://github.com/netty/netty/pull/9390#issuecomment-513008269

Modifications:

Move updateLocalWindowIfNeeded() to doBeginRead()

Result:

Reduce memory overhead
---
 .../netty/handler/codec/http2/AbstractHttp2StreamChannel.java | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/codec-http2/src/main/java/io/netty/handler/codec/http2/AbstractHttp2StreamChannel.java b/codec-http2/src/main/java/io/netty/handler/codec/http2/AbstractHttp2StreamChannel.java
index 5b4e342f85..6ccff12288 100644
--- a/codec-http2/src/main/java/io/netty/handler/codec/http2/AbstractHttp2StreamChannel.java
+++ b/codec-http2/src/main/java/io/netty/handler/codec/http2/AbstractHttp2StreamChannel.java
@@ -751,6 +751,8 @@ abstract class AbstractHttp2StreamChannel extends DefaultAttributeMap implements
             if (!isActive()) {
                 return;
             }
+            updateLocalWindowIfNeeded();
+
             switch (readStatus) {
                 case IDLE:
                     readStatus = ReadStatus.IN_PROGRESS;
@@ -827,8 +829,6 @@ abstract class AbstractHttp2StreamChannel extends DefaultAttributeMap implements
                 readStatus = ReadStatus.IDLE;
             }
 
-            updateLocalWindowIfNeeded();
-
             allocHandle.readComplete();
             pipeline().fireChannelReadComplete();
             if (config().isAutoRead()) {