X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=ltt%2Fbranches%2Fpoly%2Fltt%2Ftime.h;h=d904953099c96da1888fd1aa826966736eb91e84;hb=0aa6c3a15541d012d2ab10034090490fc2a2d1ca;hp=61c3e596c3e0bb2ca76707fa12b738be27471ab2;hpb=18206708bafbba3198bfb82cca97f17d70a05666;p=lttv.git

diff --git a/ltt/branches/poly/ltt/time.h b/ltt/branches/poly/ltt/time.h
index 61c3e596..d9049530 100644
--- a/ltt/branches/poly/ltt/time.h
+++ b/ltt/branches/poly/ltt/time.h
@@ -28,13 +28,13 @@ typedef struct _LttTime {
 } LttTime;
 
 
-static const unsigned long NANOSECONDS_PER_SECOND = 1000000000;
+#define NANOSECONDS_PER_SECOND 1000000000
 
-static const LttTime ltt_time_zero = { 0, 0};
+static const LttTime ltt_time_zero = { 0, 0 };
 
 static const LttTime ltt_time_one = { 0, 1 };
 
-static const LttTime ltt_time_infinite = { G_MAXUINT, G_MAXUINT };
+static const LttTime ltt_time_infinite = { G_MAXUINT, NANOSECONDS_PER_SECOND };
 
 static inline LttTime ltt_time_sub(LttTime t1, LttTime t2) 
 {
@@ -110,15 +110,40 @@ static inline int ltt_time_compare(LttTime t1, LttTime t2)
   return 0;
 }
 
+#define LTT_TIME_MIN(a,b) ((ltt_time_compare((a),(b)) < 0) ? (a) : (b))
+#define LTT_TIME_MAX(a,b) ((ltt_time_compare((a),(b)) > 0) ? (a) : (b))
 
+#define MAX_TV_SEC_TO_DOUBLE 0x7FFFFF
 static inline double ltt_time_to_double(LttTime t1)
 {
+  /* We lose precision if tv_sec is > than (2^23)-1
+   * 
+   * Max values that fits in a double (53 bits precision on normalised 
+   * mantissa):
+   * tv_nsec : NANOSECONDS_PER_SECONDS : 2^30
+   *
+   * So we have 53-30 = 23 bits left for tv_sec.
+   * */
+  g_assert(t1.tv_sec <= MAX_TV_SEC_TO_DOUBLE);
+  if(t1.tv_sec > MAX_TV_SEC_TO_DOUBLE)
+    g_warning("Precision loss in conversion LttTime to double");
   return (double)t1.tv_sec + (double)t1.tv_nsec / NANOSECONDS_PER_SECOND;
 }
 
 
 static inline LttTime ltt_time_from_double(double t1)
 {
+  /* We lose precision if tv_sec is > than (2^23)-1
+   * 
+   * Max values that fits in a double (53 bits precision on normalised 
+   * mantissa):
+   * tv_nsec : NANOSECONDS_PER_SECONDS : 2^30
+   *
+   * So we have 53-30 = 23 bits left for tv_sec.
+   * */
+  g_assert(t1 <= MAX_TV_SEC_TO_DOUBLE);
+  if(t1 > MAX_TV_SEC_TO_DOUBLE)
+    g_warning("Conversion from non precise double to LttTime");
   LttTime res;
   res.tv_sec = t1;
   res.tv_nsec = (t1 - res.tv_sec) * NANOSECONDS_PER_SECOND;