Add support for mach_absolute_time if on Darwin as that platform does not have clock_...

diff --git a/common.c b/common.c
index 55e4e5ff1da49cfbea22e90e510e49c90675dbf6..b509390fde035de908666c6ee564731232082713 100644 (file)
--- a/common.c
+++ b/common.c
@@ -25,6 +25,11 @@
  * SUCH DAMAGE.
  */
 
+#ifdef __APPLE__
+#  include <mach/mach_time.h>
+#  include <mach/kern_return.h>
+#endif
+
 #include <sys/param.h>
 #include <sys/time.h>
 
@@ -184,7 +189,7 @@ set_nonblock(int fd)
  * Which is why we use CLOCK_MONOTONIC, but it is not available on all
  * platforms.
  */
-#define NO_MONOTONIC "host does not support a montonic clock - timing can skew"
+#define NO_MONOTONIC "host does not support a monotonic clock - timing can skew"
 int
 get_monotonic(struct timeval *tp)
 {
@@ -193,30 +198,58 @@ get_monotonic(struct timeval *tp)
        struct timespec ts;
        static clockid_t posix_clock;
 
-       if (!posix_clock_set) {
+       if (posix_clock_set == 0) {
                if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) {
                        posix_clock = CLOCK_MONOTONIC;
                        clock_monotonic = 1;
-               } else {
-                       posix_clock = CLOCK_REALTIME;
-                       logger(LOG_WARNING, NO_MONOTONIC);
                }
                posix_clock_set = 1;
        }
 
-       if (clock_gettime(posix_clock, &ts) == -1)
-               return -1;
+       if (clock_monotonic) {
+               if (clock_gettime(posix_clock, &ts) == 0) {
+                       tp->tv_sec = ts.tv_sec;
+                       tp->tv_usec = ts.tv_nsec / 1000;
+                       return 0;
+               }
+       }
+#elif defined(__APPLE__)
+#define NSEC_PER_SEC 1000000000
+       /* We can use mach kernel functions here.
+        * This is crap though - why can't they implement clock_gettime?*/
+       static struct mach_timebase_info info = { 0, 0 };
+       static double factor = 0.0;
+       uint64_t nano;
+       long rem;
+
+       if (posix_clock_set == 0) {
+               if (mach_timebase_info(&info) == KERN_SUCCESS) {
+                       factor = (double)info.numer / (double)info.denom;
+                       clock_monotonic = 1;    
+               }
+               posix_clock_set = 1;
+       }
+       if (clock_monotonic) {
+               nano = mach_absolute_time();
+               if ((info.denom != 1 ¦¦ info.numer != 1) && factor != 0.0)
+                       nano *= factor;
+               tp.tv_sec = nano / NSEC_PER_SEC;
+               rem = nano % NSEC_PER_SEC;
+               if (rem < 0) {
+                       tp.tv_sec--;
+                       rem += NSEC_PER_SEC;
+               }
+               tp.tv_usec = rem / 1000;
+               return 0;
+       }
+#endif
 
-       tp->tv_sec = ts.tv_sec;
-       tp->tv_usec = ts.tv_nsec / 1000;
-       return 0;
-#else
+       /* Something above failed, so fall back to gettimeofday */
        if (!posix_clock_set) {
                logger(LOG_WARNING, NO_MONOTONIC);
                posix_clock_set = 1;
        }
        return gettimeofday(tp, NULL);
-#endif
 }
 
 time_t