1 files changed, 64 insertions, 0 deletions
diff --git a/support/timespec.c b/support/timespec.c
index ea6b947546..9f5449e49e 100644
--- a/support/timespec.c
+++ b/support/timespec.c
@@ -19,6 +19,8 @@
 #include <support/timespec.h>
 #include <stdio.h>
 #include <stdint.h>
+#include <assert.h>
+#include <intprops.h>
 
 void
 test_timespec_before_impl (const char *file, int line,
@@ -57,3 +59,65 @@ test_timespec_equal_or_after_impl (const char *file, int line,
 	    (intmax_t) diff.tv_sec, (intmax_t) diff.tv_nsec);
   }
 }
+
+/* Convert TIME to nanoseconds stored in a long.
+   Returns long maximum or minimum if the conversion overflows
+   or underflows, respectively.  */
+long
+support_timespec_ns (struct timespec time)
+{
+  long time_ns;
+  if (INT_MULTIPLY_WRAPV(time.tv_sec, TIMESPEC_HZ, &time_ns))
+   {
+      return (time.tv_sec < 0) ? TYPE_MINIMUM(long): TYPE_MAXIMUM(long);
+   }
+  if (INT_ADD_WRAPV(time_ns, time.tv_nsec, &time_ns))
+   {
+      return (time.tv_nsec < 0) ? TYPE_MINIMUM(long): TYPE_MAXIMUM(long);
+   }
+  return time_ns;
+}
+
+/* Returns time normalized timespec with .tv_nsec < TIMESPEC_HZ
+   and the whole seconds  added to .tv_sec. If an overflow or
+   underflow occurs the values are clamped to its maximum or
+   minimum respectively.  */
+struct timespec
+support_timespec_normalize (struct timespec time)
+{
+  struct timespec norm;
+  if (INT_ADD_WRAPV (time.tv_sec, (time.tv_nsec / TIMESPEC_HZ), &norm.tv_sec))
+   {
+     norm.tv_sec = (time.tv_nsec < 0) ? TYPE_MINIMUM (time_t): TYPE_MAXIMUM (time_t);
+     norm.tv_nsec = (time.tv_nsec < 0) ? -1 * (TIMESPEC_HZ - 1) : TIMESPEC_HZ - 1;
+     return norm;
+   }
+  norm.tv_nsec = time.tv_nsec % TIMESPEC_HZ;
+  return norm;
+}
+
+/* Returns TRUE if the observed time is within the given percentage
+   bounds of the expected time, and FALSE otherwise.
+   For example the call
+
+   support_timespec_check_in_range(expected, observed, 0.5, 1.2);
+
+   will check if
+
+   0.5 of expected <= observed <= 1.2 of expected
+
+   In other words it will check if observed time is within 50% to
+   120% of the expected time.  */
+int
+support_timespec_check_in_range (struct timespec expected, struct timespec observed,
+			      double lower_bound, double upper_bound)
+{
+  assert (upper_bound >= lower_bound);
+  long expected_norm, observed_norm;
+  expected_norm = support_timespec_ns (expected);
+  /* Don't divide by zero  */
+  assert(expected_norm != 0);
+  observed_norm = support_timespec_ns (observed);
+  double ratio = (double)observed_norm / expected_norm;
+  return (lower_bound <= ratio && ratio <= upper_bound);
+}