From ad362fc1c3560fbd88d09c7e59da83daaa2834c4 Mon Sep 17 00:00:00 2001
From: Julian Raschke <julian@raschke.de>
Date: Mon, 17 Dec 2012 01:03:21 +1000
Subject: [PATCH] Use nonblocking sockets on Win32 and OS X/iOS too

---
 src/modbus-tcp.c | 13 +++++++++++++
 1 file changed, 13 insertions(+), 0 deletions(-)

diff --git a/src/modbus-tcp.c b/src/modbus-tcp.c
index 40a5eb5..c38be50 100644
--- a/src/modbus-tcp.c
+++ b/src/modbus-tcp.c
@@ -218,6 +218,19 @@ static int _modbus_tcp_set_ipv4_options(int s)
         return -1;
     }
 
+    /* If the OS does not offer SOCK_NONBLOCK, fall back to setting FIONBIO to make sockets non-blocking */
+    /* Do not care about the return value, this is optional */
+#if !defined(SOCK_NONBLOCK) && defined(FIONBIO)
+#ifdef OS_WIN32
+    /* Setting FIONBIO expects an unsigned long according to MSDN */
+    unsigned long ioctloption = 1;
+    ioctlsocket(s, FIONBIO, &ioctloption);
+#else
+    option = 1;
+    ioctl(s, FIONBIO, &option);
+#endif
+#endif
+    
 #ifndef OS_WIN32
     /**
      * Cygwin defines IPTOS_LOWDELAY but can't handle that flag so it's
--
libgit2 0.21.4