MEDIUM: freq_ctr: reimplement freq_ctr_remain_period() from freq_ctr_total()

Now the function becomes an inline one and only contains a divide and
a max. The divide will automatically go away with constant periods.

diff --git a/include/haproxy/freq_ctr.h b/include/haproxy/freq_ctr.h
index 60166147453d0c32efd2ffa8509daf1b2fc251a6..3060f2a12d2cfe9646bc2f0da39506e174463a14 100644 (file)
--- a/include/haproxy/freq_ctr.h
+++ b/include/haproxy/freq_ctr.h
@@ -148,6 +148,20 @@ static inline uint read_freq_ctr_period(struct freq_ctr_period *ctr, uint period
  */
 unsigned int freq_ctr_remain(struct freq_ctr *ctr, unsigned int freq, unsigned int pend);
 
+/* Returns the number of remaining events that can occur on this freq counter
+ * while respecting <freq> events per period, and taking into account that
+ * <pend> events are already known to be pending. Returns 0 if limit was reached.
+ */
+static inline uint freq_ctr_remain_period(struct freq_ctr_period *ctr, uint period, uint freq, uint pend)
+{
+       ullong total = freq_ctr_total(ctr, period, pend);
+       uint avg     = div64_32(total, period);
+
+       if (avg > freq)
+               avg = freq;
+       return freq - avg;
+}
+
 /* return the expected wait time in ms before the next event may occur,
  * respecting frequency <freq>, and assuming there may already be some pending
  * events. It returns zero if we can proceed immediately, otherwise the wait
@@ -158,8 +172,6 @@ unsigned int next_event_delay(struct freq_ctr *ctr, unsigned int freq, unsigned
 
 /* process freq counters over configurable periods */
 unsigned int read_freq_ctr_period(struct freq_ctr_period *ctr, unsigned int period);
-unsigned int freq_ctr_remain_period(struct freq_ctr_period *ctr, unsigned int period,
-                                   unsigned int freq, unsigned int pend);
 
 /* While the functions above report average event counts per period, we are
  * also interested in average values per event. For this we use a different

diff --git a/src/freq_ctr.c b/src/freq_ctr.c
index a2ca040acd34c862ffc8e5a80772fefe476deb1a..d68a7841d9417470811144ab4f723a696a977d4a 100644 (file)
--- a/src/freq_ctr.c
+++ b/src/freq_ctr.c
@@ -166,56 +166,6 @@ unsigned int next_event_delay(struct freq_ctr *ctr, unsigned int freq, unsigned
        return MAX(wait, 1);
 }
 
-/* Returns the number of remaining events that can occur on this freq counter
- * while respecting <freq> events per period, and taking into account that
- * <pend> events are already known to be pending. Returns 0 if limit was reached.
- */
-unsigned int freq_ctr_remain_period(struct freq_ctr_period *ctr, unsigned int period,
-                                   unsigned int freq, unsigned int pend)
-{
-       unsigned int _curr, _past, curr, past;
-       unsigned int remain, _curr_tick, curr_tick;
-
-       while (1) {
-               _curr = ctr->curr_ctr;
-               __ha_compiler_barrier();
-               _past = ctr->prev_ctr;
-               __ha_compiler_barrier();
-               _curr_tick = ctr->curr_tick;
-               __ha_compiler_barrier();
-               if (_curr_tick & 0x1)
-                       continue;
-               curr = ctr->curr_ctr;
-               __ha_compiler_barrier();
-               past = ctr->prev_ctr;
-               __ha_compiler_barrier();
-               curr_tick = ctr->curr_tick;
-               __ha_compiler_barrier();
-               if (_curr == curr && _past == past && _curr_tick == curr_tick)
-                       break;
-       };
-
-       remain = curr_tick + period - global_now_ms;
-       if (likely((int)remain < 0)) {
-               /* We're past the first period, check if we can still report a
-                * part of last period or if we're too far away.
-                */
-               past = curr;
-               curr = 0;
-               remain += period;
-               if ((int)remain < 0)
-                       past = 0;
-       }
-       if (likely(past))
-               curr += div64_32((unsigned long long)past * remain, period);
-
-       curr += pend;
-       freq -= curr;
-       if ((int)freq < 0)
-               freq = 0;
-       return freq;
-}
-
 /* Returns the total number of events over the current + last period, including
  * a number of already pending events <pend>. The average frequency will be
  * obtained by dividing the output by <period>. This is essentially made to