1 files changed, 185 insertions, 2 deletions

diff --git a/src/common/compat_time.c b/src/common/compat_time.c
index 1ce6f5ce4e..183a60a480 100644
--- a/src/common/compat_time.c
+++ b/src/common/compat_time.c
@@ -90,7 +90,7 @@ tor_gettimeofday(struct timeval *timeval)
   if (ft.ft_64 < EPOCH_BIAS) {
     /* LCOV_EXCL_START */
     log_err(LD_GENERAL,"System time is before 1970; failing.");
-    exit(1);
+    exit(1); // exit ok: system clock is broken.
     /* LCOV_EXCL_STOP */
   }
   ft.ft_64 -= EPOCH_BIAS;
@@ -102,7 +102,7 @@ tor_gettimeofday(struct timeval *timeval)
     log_err(LD_GENERAL,"gettimeofday failed.");
     /* If gettimeofday dies, we have either given a bad timezone (we didn't),
        or segfaulted.*/
-    exit(1);
+    exit(1); // exit ok: gettimeofday failed.
     /* LCOV_EXCL_STOP */
   }
 #elif defined(HAVE_FTIME)
@@ -279,6 +279,7 @@ monotime_reset_ratchets_for_testing(void)
  * nanoseconds.
  */
 static struct mach_timebase_info mach_time_info;
+static int monotime_shift = 0;
 
 static void
 monotime_init_internal(void)
@@ -287,6 +288,14 @@ monotime_init_internal(void)
   int r = mach_timebase_info(&mach_time_info);
   tor_assert(r == 0);
   tor_assert(mach_time_info.denom != 0);
+
+  {
+    // approximate only.
+    uint64_t ns_per_tick = mach_time_info.numer / mach_time_info.denom;
+    uint64_t ms_per_tick = ns_per_tick * ONE_MILLION;
+    // requires that tor_log2(0) == 0.
+    monotime_shift = tor_log2(ms_per_tick);
+  }
 }
 
 /**
@@ -305,6 +314,21 @@ monotime_get(monotime_t *out)
   out->abstime_ = mach_absolute_time();
 }
 
+#if defined(HAVE_MACH_APPROXIMATE_TIME)
+void
+monotime_coarse_get(monotime_coarse_t *out)
+{
+#ifdef TOR_UNIT_TESTS
+  if (monotime_mocking_enabled) {
+    out->abstime_ = (mock_time_nsec_coarse * mach_time_info.denom)
+      / mach_time_info.numer;
+    return;
+  }
+#endif /* defined(TOR_UNIT_TESTS) */
+  out->abstime_ = mach_approximate_time();
+}
+#endif
+
 /**
  * Return the number of nanoseconds between <b>start</b> and <b>end</b>.
  */
@@ -321,6 +345,26 @@ monotime_diff_nsec(const monotime_t *start,
   return diff_nsec;
 }
 
+uint32_t
+monotime_coarse_to_stamp(const monotime_coarse_t *t)
+{
+  return (uint32_t)(t->abstime_ >> monotime_shift);
+}
+
+int
+monotime_is_zero(const monotime_t *val)
+{
+  return val->abstime_ == 0;
+}
+
+void
+monotime_add_msec(monotime_t *out, const monotime_t *val, uint32_t msec)
+{
+  const uint64_t nsec = msec * ONE_MILLION;
+  const uint64_t ticks = (nsec * mach_time_info.denom) / mach_time_info.numer;
+  out->abstime_ = val->abstime_ + ticks;
+}
+
 /* end of "__APPLE__" */
 #elif defined(HAVE_CLOCK_GETTIME)
 
@@ -399,6 +443,37 @@ monotime_diff_nsec(const monotime_t *start,
   return diff_nsec;
 }
 
+/* This value is ONE_BILLION >> 20. */
+static const uint32_t STAMP_TICKS_PER_SECOND = 953;
+
+uint32_t
+monotime_coarse_to_stamp(const monotime_coarse_t *t)
+{
+  uint32_t nsec = (uint32_t)t->ts_.tv_nsec;
+  uint32_t sec = (uint32_t)t->ts_.tv_sec;
+
+  return (sec * STAMP_TICKS_PER_SECOND) + (nsec >> 20);
+}
+
+int
+monotime_is_zero(const monotime_t *val)
+{
+  return val->ts_.tv_sec == 0 && val->ts_.tv_nsec == 0;
+}
+
+void
+monotime_add_msec(monotime_t *out, const monotime_t *val, uint32_t msec)
+{
+  const uint32_t sec = msec / 1000;
+  const uint32_t msec_remainder = msec % 1000;
+  out->ts_.tv_sec = val->ts_.tv_sec + sec;
+  out->ts_.tv_nsec = val->ts_.tv_nsec + (msec_remainder * ONE_MILLION);
+  if (out->ts_.tv_nsec > ONE_BILLION) {
+    out->ts_.tv_nsec -= ONE_BILLION;
+    out->ts_.tv_sec += 1;
+  }
+}
+
 /* end of "HAVE_CLOCK_GETTIME" */
 #elif defined (_WIN32)
 
@@ -531,6 +606,41 @@ monotime_coarse_diff_nsec(const monotime_coarse_t *start,
   return monotime_coarse_diff_msec(start, end) * ONE_MILLION;
 }
 
+static const uint32_t STAMP_TICKS_PER_SECOND = 1000;
+
+uint32_t
+monotime_coarse_to_stamp(const monotime_coarse_t *t)
+{
+  return (uint32_t) t->tick_count_;
+}
+
+int
+monotime_is_zero(const monotime_t *val)
+{
+  return val->pcount_ == 0;
+}
+
+int
+monotime_coarse_is_zero(const monotime_coarse_t *val)
+{
+  return val->tick_count_ == 0;
+}
+
+void
+monotime_add_msec(monotime_t *out, const monotime_t *val, uint32_t msec)
+{
+  const uint64_t nsec = msec * ONE_MILLION;
+  const uint64_t ticks = (nsec * nsec_per_tick_denom) / nsec_per_tick_numer;
+  out->pcount_ = val->pcount_ + ticks;
+}
+
+void
+monotime_coarse_add_msec(monotime_coarse_t *out, const monotime_coarse_t *val,
+                         uint32_t msec)
+{
+  out->tick_count_ = val->tick_count_ + msec;
+}
+
 /* end of "_WIN32" */
 #elif defined(MONOTIME_USING_GETTIMEOFDAY)
 
@@ -567,6 +677,36 @@ monotime_diff_nsec(const monotime_t *start,
   return (diff.tv_sec * ONE_BILLION + diff.tv_usec * 1000);
 }
 
+/* This value is ONE_MILLION >> 10. */
+static const uint32_t STAMP_TICKS_PER_SECOND = 976;
+
+uint32_t
+monotime_coarse_to_stamp(const monotime_coarse_t *t)
+{
+  const uint32_t usec = (uint32_t)t->tv_.tv_usec;
+  const uint32_t sec = (uint32_t)t->tv_.tv_sec;
+  return (sec * STAMP_TICKS_PER_SECOND) | (nsec >> 10);
+}
+
+int
+monotime_is_zero(const monotime_t *val)
+{
+  return val->tv_.tv_sec == 0 && val->tv_.tv_usec == 0;
+}
+
+void
+monotime_add_msec(monotime_t *out, const monotime_t *val, uint32_t msec)
+{
+  const uint32_t sec = msec / 1000;
+  const uint32_t msec_remainder = msec % 1000;
+  out->tv_.tv_sec = val->tv_.tv_sec + sec;
+  out->tv_.tv_usec = val->tv_.tv_nsec + (msec_remainder * 1000);
+  if (out->tv_.tv_usec > ONE_MILLION) {
+    out->tv_.tv_usec -= ONE_MILLION;
+    out->tv_.tv_sec += 1;
+  }
+}
+
 /* end of "MONOTIME_USING_GETTIMEOFDAY" */
 #else
 #error "No way to implement monotonic timers."
@@ -589,6 +729,19 @@ monotime_init(void)
   }
 }
 
+void
+monotime_zero(monotime_t *out)
+{
+  memset(out, 0, sizeof(*out));
+}
+#ifdef MONOTIME_COARSE_TYPE_IS_DIFFERENT
+void
+monotime_coarse_zero(monotime_coarse_t *out)
+{
+  memset(out, 0, sizeof(*out));
+}
+#endif
+
 int64_t
 monotime_diff_usec(const monotime_t *start,
                    const monotime_t *end)
@@ -653,5 +806,35 @@ monotime_coarse_absolute_msec(void)
 {
   return monotime_coarse_absolute_nsec() / ONE_MILLION;
 }
+#else
+#define initialized_at_coarse initialized_at
 #endif /* defined(MONOTIME_COARSE_FN_IS_DIFFERENT) */
 
+/**
+ * Return the current time "stamp" as described by monotime_coarse_to_stamp.
+ */
+uint32_t
+monotime_coarse_get_stamp(void)
+{
+  monotime_coarse_t now;
+  monotime_coarse_get(&now);
+  return monotime_coarse_to_stamp(&now);
+}
+
+#ifdef __APPLE__
+uint64_t
+monotime_coarse_stamp_units_to_approx_msec(uint64_t units)
+{
+  /* Recover as much precision as we can. */
+  uint64_t abstime_diff = (units << monotime_shift);
+  return (abstime_diff * mach_time_info.numer) /
+    (mach_time_info.denom * ONE_MILLION);
+}
+#else
+uint64_t
+monotime_coarse_stamp_units_to_approx_msec(uint64_t units)
+{
+  return (units * 1000) / STAMP_TICKS_PER_SECOND;
+}
+#endif
+