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Diffstat (limited to 'src/core/time_cc.c')
| -rw-r--r-- | src/core/time_cc.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/src/core/time_cc.c b/src/core/time_cc.c new file mode 100644 index 00000000..0e6879e5 --- /dev/null +++ b/src/core/time_cc.c @@ -0,0 +1,228 @@ +/*! \file foo.c + * Report the cumulative counter of time for which a flag is true as rate counter. + */ +/* Copyright (C) 2021 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> + * + * All Rights Reserved + * + * Author: Neels Hofmeyr <nhofmeyr@sysmocom.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Affero General Public License for more details. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + */ + +/*! \addtogroup time_cc + * + * Report the cumulative counter of time for which a flag is true as rate counter. + * + * Useful for reporting cumulative time counters as defined in 3GPP TS 52.402, for example allAvailableSDCCHAllocated, + * allAvailableTCHAllocated, availablePDCHAllocatedTime. + * + * For a usage example, see the description of struct osmo_time_cc. + * + * @{ + * \file time_cc.c + */ +#include "config.h" +#ifdef HAVE_CLOCK_GETTIME + +#include <limits.h> +#include <time.h> + +#include <osmocom/core/tdef.h> +#include <osmocom/core/rate_ctr.h> +#include <osmocom/core/time_cc.h> + +#define GRAN_USEC(TIME_CC) ((TIME_CC)->cfg.gran_usec ? : 1000000) +#define ROUND_THRESHOLD_USEC(TIME_CC) ((TIME_CC)->cfg.round_threshold_usec ? \ + OSMO_MIN((TIME_CC)->cfg.round_threshold_usec, GRAN_USEC(TIME_CC)) \ + : (GRAN_USEC(TIME_CC) / 2)) + +static uint64_t time_now_usec(void) +{ + struct timespec tp; + if (osmo_clock_gettime(CLOCK_MONOTONIC, &tp)) + return 0; + return (uint64_t)tp.tv_sec * 1000000 + tp.tv_nsec / 1000; +} + +static void osmo_time_cc_forget_sum(struct osmo_time_cc *tc, uint64_t now); + +static void osmo_time_cc_update_from_tdef(struct osmo_time_cc *tc, uint64_t now) +{ + bool do_forget_sum = false; + if (!tc->cfg.T_defs) + return; + if (tc->cfg.T_gran) { + uint64_t was = GRAN_USEC(tc); + tc->cfg.gran_usec = osmo_tdef_get(tc->cfg.T_defs, tc->cfg.T_gran, OSMO_TDEF_US, -1); + if (was != GRAN_USEC(tc)) + do_forget_sum = true; + } + if (tc->cfg.T_round_threshold) + tc->cfg.round_threshold_usec = osmo_tdef_get(tc->cfg.T_defs, tc->cfg.T_round_threshold, + OSMO_TDEF_US, -1); + if (tc->cfg.T_forget_sum) { + uint64_t was = tc->cfg.forget_sum_usec; + tc->cfg.forget_sum_usec = osmo_tdef_get(tc->cfg.T_defs, tc->cfg.T_forget_sum, OSMO_TDEF_US, -1); + if (tc->cfg.forget_sum_usec && was != tc->cfg.forget_sum_usec) + do_forget_sum = true; + } + + if (do_forget_sum && tc->sum) + osmo_time_cc_forget_sum(tc, now); +} + +static void osmo_time_cc_schedule_timer(struct osmo_time_cc *tc, uint64_t now); + +/*! Clear out osmo_timer and internal counting state of struct osmo_time_cc. The .cfg remains unaffected. After calling, + * the osmo_time_cc instance can be used again to accumulate state as if it had just been initialized. */ +void osmo_time_cc_cleanup(struct osmo_time_cc *tc) +{ + osmo_timer_del(&tc->timer); + *tc = (struct osmo_time_cc){ + .cfg = tc->cfg, + }; +} + +static void osmo_time_cc_start(struct osmo_time_cc *tc, uint64_t now) +{ + osmo_time_cc_cleanup(tc); + tc->start_time = now; + tc->last_counted_time = now; + osmo_time_cc_update_from_tdef(tc, now); + osmo_time_cc_schedule_timer(tc, now); +} + +static void osmo_time_cc_count_time(struct osmo_time_cc *tc, uint64_t now) +{ + uint64_t time_delta = now - tc->last_counted_time; + tc->last_counted_time = now; + if (!tc->flag_state) + return; + /* Flag is currently true, cumulate the elapsed time */ + tc->total_sum += time_delta; + tc->sum += time_delta; +} + +static void osmo_time_cc_report(struct osmo_time_cc *tc, uint64_t now) +{ + uint64_t delta; + uint64_t n; + /* 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) + return; + delta = tc->sum - tc->reported_sum; + /* elapsed full periods */ + n = delta / GRAN_USEC(tc); + /* If the delta has passed round_threshold (normally half of gran_usec), increment. */ + delta -= n * GRAN_USEC(tc); + if (delta >= ROUND_THRESHOLD_USEC(tc)) + n++; + if (!n) + return; + + /* integer sanity, since rate_ctr_add() takes an int argument. */ + if (n > INT_MAX) + n = INT_MAX; + 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); +} + +static void osmo_time_cc_forget_sum(struct osmo_time_cc *tc, uint64_t now) +{ + tc->reported_sum = 0; + tc->sum = 0; + + if (tc->last_counted_time < now) + tc->last_counted_time = now; +} + +/*! Initialize struct osmo_time_cc. Call this once before use, and before setting up the .cfg items. */ +void osmo_time_cc_init(struct osmo_time_cc *tc) +{ + *tc = (struct osmo_time_cc){0}; +} + +/*! Report state to be recorded by osmo_time_cc instance. Setting an unchanged state repeatedly has no effect. */ +void osmo_time_cc_set_flag(struct osmo_time_cc *tc, bool flag) +{ + uint64_t now = time_now_usec(); + if (!tc->start_time) + osmo_time_cc_start(tc, now); + /* No flag change == no effect */ + if (flag == tc->flag_state) + return; + /* Sum up elapsed time, report increments for that. */ + osmo_time_cc_count_time(tc, now); + osmo_time_cc_report(tc, now); + tc->flag_state = flag; + osmo_time_cc_schedule_timer(tc, now); +} + +static void osmo_time_cc_timer_cb(void *data) +{ + struct osmo_time_cc *tc = data; + uint64_t now = time_now_usec(); + + osmo_time_cc_update_from_tdef(tc, now); + + if (tc->flag_state) { + osmo_time_cc_count_time(tc, now); + osmo_time_cc_report(tc, now); + } else if (tc->cfg.forget_sum_usec && tc->sum + && (now >= tc->last_counted_time + tc->cfg.forget_sum_usec)) { + osmo_time_cc_forget_sum(tc, now); + } + osmo_time_cc_schedule_timer(tc, now); +} + +/*! Figure out the next time we should do anything, if the flag state remains unchanged. */ +static void osmo_time_cc_schedule_timer(struct osmo_time_cc *tc, uint64_t now) +{ + uint64_t next_event = UINT64_MAX; + + osmo_time_cc_update_from_tdef(tc, now); + + /* If it is required, when will the next forget_sum happen? */ + if (tc->cfg.forget_sum_usec && !tc->flag_state && tc->sum > 0) { + uint64_t next_forget_time = tc->last_counted_time + tc->cfg.forget_sum_usec; + next_event = OSMO_MIN(next_event, next_forget_time); + } + /* Next rate_ctr increment? */ + 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); + } + + /* No event coming up? */ + if (next_event == UINT64_MAX) + return; + + if (next_event <= now) + next_event = 0; + else + next_event -= now; + + osmo_timer_setup(&tc->timer, osmo_time_cc_timer_cb, tc); + osmo_timer_del(&tc->timer); + osmo_timer_schedule(&tc->timer, next_event / 1000000, next_event % 1000000); +} + +#endif /* HAVE_CLOCK_GETTIME */ + +/*! @} */ |