From 2e10351fcc84141ed2b26862bbe1082bd2ca48b9 Mon Sep 17 00:00:00 2001
From: Lorenz Meier <lm@inf.ethz.ch>
Date: Sun, 6 Dec 2015 11:40:22 +0100
Subject: [PATCH] Fix HRT abstraction for Mac OS

---
 src/platforms/posix/px4_layer/drv_hrt.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/platforms/posix/px4_layer/drv_hrt.c b/src/platforms/posix/px4_layer/drv_hrt.c
index e4839f0ac7..3bb8fa129f 100644
--- a/src/platforms/posix/px4_layer/drv_hrt.c
+++ b/src/platforms/posix/px4_layer/drv_hrt.c
@@ -86,6 +86,10 @@ static void hrt_unlock(void)
 #include <sys/time.h>
 #define CLOCK_REALTIME 0
 
+#ifndef CLOCK_MONOTONIC
+#define CLOCK_MONOTONIC 1
+#endif
+
 int px4_clock_gettime(clockid_t clk_id, struct timespec *tp)
 {
 	struct timeval now;