[commit: ghc] master: Use monotonic time function for darwin (#5865) (e57d23d)

[Paolo Capriotti]

Repository : ssh://darcs.haskell.org//srv/darcs/ghc

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/e57d23d6f11c1262a096f2135e64a6a81d0ca938

>---------------------------------------------------------------

commit e57d23d6f11c1262a096f2135e64a6a81d0ca938
Author: Paolo Capriotti <p.capriotti at gmail.com>
Date:   Sat Mar 24 02:19:43 2012 +0000

    Use monotonic time function for darwin (#5865)

>---------------------------------------------------------------

 rts/posix/Clock.h   |    3 +++
 rts/posix/GetTime.c |   11 +++++++++++
 2 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/rts/posix/Clock.h b/rts/posix/Clock.h
index 5062023..2c71d7a 100644
--- a/rts/posix/Clock.h
+++ b/rts/posix/Clock.h
@@ -27,6 +27,9 @@
 # else
 #  define CLOCK_ID CLOCK_REALTIME
 # endif
+#elif defined(darwin_HOST_OS)
+# include <mach/mach.h>
+# include <mach/mach_time.h>
 #endif
 
 #endif /* POSIX_CLOCK_H */
diff --git a/rts/posix/GetTime.c b/rts/posix/GetTime.c
index 4abc82f..549b3b0 100644
--- a/rts/posix/GetTime.c
+++ b/rts/posix/GetTime.c
@@ -71,6 +71,17 @@ Time getProcessElapsedTime(void)
 
     clock_gettime(CLOCK_ID, &ts);
     return SecondsToTime(ts.tv_sec) + NSToTime(ts.tv_nsec);
+#elif defined(darwin_HOST_OS)
+    uint64_t time = mach_absolute_time();
+    static double scaling_factor = 0.0;
+
+    if (scaling_factor == 0.0) {
+        mach_timebase_info_data_t info;
+        (void) mach_timebase_info(&info);
+        scaling_factor = (double)info.numer / (double)info.denom;
+    }
+
+    return (Time)((double)time * scaling_factor);
 #else
     struct timeval tv;