From b7071869d1830f9e8c6d069d8652c4ff43b51a00 Mon Sep 17 00:00:00 2001
From: Davide Gerhard <rainbow@irh.it>
Date: Sat, 11 May 2019 11:14:59 +0200
Subject: [PATCH] fix clock_gettime() con macOS <10.12 (not provided by base)

---
 custom/apple/apple_compat.c | 21 +---------------
 custom/apple/apple_compat.h | 48 ++++++++++++++++++++++++++++++-------
 qrtplib/CMakeLists.txt      |  2 --
 qrtplib/rtptimeutilities.h  |  4 ++++
 4 files changed, 45 insertions(+), 30 deletions(-)

diff --git a/custom/apple/apple_compat.c b/custom/apple/apple_compat.c
index c8775a1d7..642fb96e7 100644
--- a/custom/apple/apple_compat.c
+++ b/custom/apple/apple_compat.c
@@ -57,23 +57,4 @@ int pthread_barrier_wait(pthread_barrier_t *barrier)
     }
 }
 
-#ifdef _DARWIN_FEATURE_CLOCK_GETTIME
-/**
- * Missing POSIX RealTime/Monotonic Clock
- */
-#include <mach/mach_time.h>
-
-int clock_gettime(int clk_id, struct timespec *t) {
-    mach_timebase_info_data_t timebase;
-    mach_timebase_info(&timebase);
-    uint64_t time;
-    time = mach_absolute_time();
-    double nseconds = ((double)time * (double)timebase.numer)/((double)timebase.denom);
-    double seconds = ((double)time * (double)timebase.numer)/((double)timebase.denom * 1e9);
-    t->tv_sec = seconds;
-    t->tv_nsec = nseconds;
-    return 0;
-}
-#endif
-
-#endif // APPLE Compatibility
+#endif // __APPLE_
diff --git a/custom/apple/apple_compat.h b/custom/apple/apple_compat.h
index ea583d3fa..8ab0956b2 100644
--- a/custom/apple/apple_compat.h
+++ b/custom/apple/apple_compat.h
@@ -31,13 +31,45 @@ int pthread_barrier_wait(pthread_barrier_t *barrier);
 
 #endif // PTHREAD_BARRIER_H_
 
-// <time.h>
-#ifndef CLOCK_REALTIME
-#  define CLOCK_REALTIME 0
-#endif
 
-#ifndef CLOCK_MONOTONIC
-#  define CLOCK_MONOTONIC 0
-#endif
+// macOS < 10.12 doesn't have clock_gettime()
+#include <time.h>
+#if !defined(CLOCK_REALTIME) && !defined(CLOCK_MONOTONIC)
 
-#endif // APPLE Compatibility
+#define CLOCK_REALTIME  0
+#define CLOCK_MONOTONIC 6
+typedef int clockid_t;
+
+#include <sys/time.h>
+#include <mach/mach_time.h>
+
+// here to avoid problem on linking of qrtplib
+inline int clock_gettime( clockid_t clk_id, struct timespec *ts )
+{
+  int ret = -1;
+  if ( ts )
+  {
+    if      ( CLOCK_REALTIME == clk_id )
+    {
+      struct timeval tv;
+      ret = gettimeofday(&tv, NULL);
+      ts->tv_sec  = tv.tv_sec;
+      ts->tv_nsec = tv.tv_usec * 1000;
+    }
+    else if ( CLOCK_MONOTONIC == clk_id )
+    {
+      const uint64_t t = mach_absolute_time();
+      mach_timebase_info_data_t timebase;
+      mach_timebase_info(&timebase);
+      const uint64_t tdiff = t * timebase.numer / timebase.denom;
+      ts->tv_sec  = tdiff / 1000000000;
+      ts->tv_nsec = tdiff % 1000000000;
+      ret = 0;
+    }
+  }
+  return ret;
+}
+
+#endif // CLOCK_REALTIME and CLOCK_MONOTONIC
+
+#endif // __APPLE__
diff --git a/qrtplib/CMakeLists.txt b/qrtplib/CMakeLists.txt
index 072a61d55..0c75ee075 100644
--- a/qrtplib/CMakeLists.txt
+++ b/qrtplib/CMakeLists.txt
@@ -1,7 +1,6 @@
 project(qrtplib)
 
 set (qrtplib_HEADERS
-    ../custom/apple/apple_compat.h
     rtcpapppacket.h
     rtcpbyepacket.h
     rtcpcompoundpacket.h
@@ -44,7 +43,6 @@ set (qrtplib_HEADERS
     )
 
 set(qrtplib_SOURCES
-    ../custom/apple/apple_compat.c
     rtcpapppacket.cpp
     rtcpbyepacket.cpp
     rtcpcompoundpacket.cpp
diff --git a/qrtplib/rtptimeutilities.h b/qrtplib/rtptimeutilities.h
index 526141777..8b460f659 100644
--- a/qrtplib/rtptimeutilities.h
+++ b/qrtplib/rtptimeutilities.h
@@ -60,6 +60,10 @@
 #define CEPOCH 11644473600000000ULL
 #endif // RTP_HAVE_VSUINT64SUFFIX
 
+#ifdef __APPLE__
+#include   "../custom/apple/apple_compat.h"
+#endif
+
 namespace qrtplib
 {