From 94fdf442f8b9dda50fe1793187c06f4b47e9ef92 Mon Sep 17 00:00:00 2001
From: Scott Mitchell <scott_mitchell@apple.com>
Date: Tue, 2 Jun 2015 12:17:32 -0700
Subject: [PATCH] TCP_NOTSENT_LOWAT older kernel compatibility

Motiviation:
TCP_NOTSENT_LOWAT is only supported in linux kernel 3.12 or newer. The addition of this socket option prevents older kernels from building.

Modifications:
- Conditionally define TCP_NOTSENT_LOWAT if it is not defined

Result:
Kernels older than 3.12 can still compile the EPOLL module.
---
 .../src/main/c/io_netty_channel_epoll_Native.c               | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/transport-native-epoll/src/main/c/io_netty_channel_epoll_Native.c b/transport-native-epoll/src/main/c/io_netty_channel_epoll_Native.c
index 16f3c954cb..9ecdc95eae 100644
--- a/transport-native-epoll/src/main/c/io_netty_channel_epoll_Native.c
+++ b/transport-native-epoll/src/main/c/io_netty_channel_epoll_Native.c
@@ -35,6 +35,11 @@
 #include "io_netty_channel_epoll_Native.h"
 #include "exception_helper.h"
 
+// TCP_NOTSENT_LOWAT is defined in linux 3.12. We define this here so older kernels can compile.
+#ifndef TCP_NOTSENT_LOWAT
+#define TCP_NOTSENT_LOWAT 25
+#endif
+
 /**
  * On older Linux kernels, epoll can't handle timeout
  * values bigger than (LONG_MAX - 999ULL)/HZ.