From 192e77492a2a53a89a6cb9f34f3aed634ffd6956 Mon Sep 17 00:00:00 2001
From: Martin Ling <martin-git@earth.li>
Date: Sun, 23 Sep 2018 17:43:46 +0100
Subject: [PATCH] Use mach_absolute_time() on OSX without clock_gettime().

This should fix #759 for OSX versions below 10.12.
---
 libserialport_internal.h | 1 +
 serialport.c             | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/libserialport_internal.h b/libserialport_internal.h
index ec15f58..dd69733 100644
--- a/libserialport_internal.h
+++ b/libserialport_internal.h
@@ -62,6 +62,7 @@
 #include <IOKit/serial/IOSerialKeys.h>
 #include <IOKit/serial/ioss.h>
 #include <sys/syslimits.h>
+#include <mach/mach_time.h>
 #endif
 #ifdef __linux__
 #include <dirent.h>
diff --git a/serialport.c b/serialport.c
index 15ca1fd..6e68153 100644
--- a/serialport.c
+++ b/serialport.c
@@ -64,6 +64,13 @@ static void get_time(struct timeval *time)
 	clock_gettime(CLOCK_MONOTONIC, &ts);
 	time->tv_sec = ts.tv_sec;
 	time->tv_usec = ts.tv_nsec / 1000;
+#elif defined(__APPLE__)
+	mach_timebase_info_data_t info;
+	mach_timebase_info(&info);
+	uint64_t ticks = mach_absolute_time();
+	uint64_t ns = (ticks * info.numer) / info.denom;
+	time->tv_sec = ns / 1000000000;
+	time->tv_usec = (ns % 1000000000) / 1000;
 #else
 	gettimeofday(time, NULL);
 #endif