neels has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmocore/+/27425 )

Change subject: osmo_time_cc: rate_ctr presence should not affect counting ......................................................................

osmo_time_cc: rate_ctr presence should not affect counting

Make sure that osmo_time_cc counts exactly the same, regardless of a rate_ctr being present or not. Only skip sending counter increments when there is no rate counter, do not affect anything else.

In osmo-bsc, we are discussing a patch where an lchan redirects osmo_time_cc counter increments to different rate counters depending on its current type. In my comments I am also claiming that osmo_time_cc works the same regardless of a rate_ctr being present or not. Looking at the code, this is not actually the case.

Before this patch, when there is no rate_ctr, the reported_sum would freeze, and as soon as a rate_ctr shows up, all counter increments from the previous reported_sum would be sent to the newly set rate_ctr. Instead, we want counter increments to simply be lost while there is no rate_ctr set. IOW, rate_ctr == NULL should mean >/dev/null.

Related: I1b0670c47cb5e0b7776eda89d1e71545ba0e3347 (osmo-bsc) Change-Id: I380b28d7ab0a6c8aab6c7e2a64bc73cab14863d2 --- M src/time_cc.c 1 file changed, 3 insertions(+), 4 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/25/27425/1

diff --git a/src/time_cc.c b/src/time_cc.c index ae99b58..05971fe 100644 --- a/src/time_cc.c +++ b/src/time_cc.c @@ -120,8 +120,6 @@ { uint64_t delta; uint64_t n; - if (!tc->cfg.rate_ctr) - return; /* We report a sum "rounded up", ahead of time. If the granularity period has not yet elapsed after the last * reporting, do not report again yet. */ if (tc->reported_sum > tc->sum) @@ -139,7 +137,8 @@ /* integer sanity, since rate_ctr_add() takes an int argument. */ if (n > INT_MAX) n = INT_MAX; - rate_ctr_add(tc->cfg.rate_ctr, n); + if (tc->cfg.rate_ctr) + rate_ctr_add(tc->cfg.rate_ctr, n); /* Store the increments of gran_usec that were counted. */ tc->reported_sum += n * GRAN_USEC(tc); } @@ -205,7 +204,7 @@ next_event = OSMO_MIN(next_event, next_forget_time); } /* Next rate_ctr increment? */ - if (tc->flag_state && tc->cfg.rate_ctr) { + if (tc->flag_state) { uint64_t next_inc = now + (tc->reported_sum - tc->sum) + ROUND_THRESHOLD_USEC(tc); next_event = OSMO_MIN(next_event, next_inc); }