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Diffstat (limited to 'src/core/rate_ctr.c')
| -rw-r--r-- | src/core/rate_ctr.c | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/src/core/rate_ctr.c b/src/core/rate_ctr.c new file mode 100644 index 00000000..44e26585 --- /dev/null +++ b/src/core/rate_ctr.c @@ -0,0 +1,499 @@ +/* (C) 2009-2017 by Harald Welte <laforge@gnumonks.org> + * + * All Rights Reserved + * + * SPDX-License-Identifier: GPL-2.0+ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 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 General Public License for more details. + * + */ + +/*! \addtogroup rate_ctr + * @{ + * Counters about events and their event rates. + * + * As \ref osmo_counter and \ref osmo_stat_item are concerned only with + * a single given value that may be increased/decreased, or the difference + * to one given previous value, this module adds some support for keeping + * long term information about a given event rate. + * + * A \ref rate_ctr keeps information on the amount of events per second, + * per minute, per hour and per day. + * + * \ref rate_ctr come in groups: An application describes a group of counters + * with their names and identities once in a (typically const) \ref + * rate_ctr_group_desc. + * + * As objects (such as e.g. a subscriber or a PDP context) are + * allocated dynamically at runtime, the application calls \ref + * rate_ctr_group_alloc with a refernce to the \ref + * rate_ctr_group_desc, which causes the library to allocate one set of + * \ref rate_ctr: One for each in the group. + * + * The application then uses functions like \ref rate_ctr_add or \ref + * rate_ctr_inc to increment the value as certain events (e.g. location + * update) happens. + * + * The library internally keeps a timer once per second which iterates + * over all registered counters and which updates the per-second, + * per-minute, per-hour and per-day averages based on the current + * value. + * + * The counters can be reported using \ref stats or by VTY + * introspection, as well as by any application-specific code accessing + * the \ref rate_ctr.intv array directly. + * + * \file rate_ctr.c */ + +#include <errno.h> +#include <stdbool.h> +#include <stdint.h> +#include <string.h> +#include <unistd.h> +#include <inttypes.h> + +#include <osmocom/core/utils.h> +#include <osmocom/core/linuxlist.h> +#include <osmocom/core/talloc.h> +#include <osmocom/core/select.h> +#include <osmocom/core/rate_ctr.h> +#include <osmocom/core/logging.h> + +static LLIST_HEAD(rate_ctr_groups); + +static void *tall_rate_ctr_ctx; + + +static bool rate_ctrl_group_desc_validate(const struct rate_ctr_group_desc *desc) +{ + unsigned int i; + const struct rate_ctr_desc *ctr_desc; + + if (!desc) { + LOGP(DLGLOBAL, LOGL_ERROR, "NULL is not a valid counter group descriptor\n"); + return false; + } + ctr_desc = desc->ctr_desc; + + DEBUGP(DLGLOBAL, "validating counter group %p(%s) with %u counters\n", desc, + desc->group_name_prefix, desc->num_ctr); + + if (!osmo_identifier_valid(desc->group_name_prefix)) { + LOGP(DLGLOBAL, LOGL_ERROR, "'%s' is not a valid counter group identifier\n", + desc->group_name_prefix); + return false; + } + + for (i = 0; i < desc->num_ctr; i++) { + if (!osmo_identifier_valid(ctr_desc[i].name)) { + LOGP(DLGLOBAL, LOGL_ERROR, "'%s' is not a valid counter identifier\n", + ctr_desc[i].name); + return false; + } + } + + return true; +} + +/* return 'in' if it doesn't contain any '.'; otherwise allocate a copy and + * replace all '.' with ':' */ +static char *mangle_identifier_ifneeded(const void *ctx, const char *in) +{ + char *out; + unsigned int i; + bool modified = false; + + if (!in) + return NULL; + + if (!strchr(in, '.')) + return (char *)in; + + out = talloc_strdup(ctx, in); + OSMO_ASSERT(out); + + for (i = 0; i < strlen(out); i++) { + if (out[i] == '.') { + out[i] = ':'; + modified = true; + } + } + + if (modified) + LOGP(DLGLOBAL, LOGL_NOTICE, "counter group name mangled: '%s' -> '%s'\n", + in, out); + + return out; +} + +/* "mangle" a rate counter group descriptor, i.e. replace any '.' with ':' */ +static struct rate_ctr_group_desc * +rate_ctr_group_desc_mangle(void *ctx, const struct rate_ctr_group_desc *desc) +{ + struct rate_ctr_group_desc *desc_new = talloc_zero(ctx, struct rate_ctr_group_desc); + int i; + + OSMO_ASSERT(desc_new); + + LOGP(DLGLOBAL, LOGL_INFO, "Needed to mangle counter group '%s' names: it is still using '.' as " + "separator, which is not allowed. please consider updating the application\n", + desc->group_name_prefix); + + /* mangle the name_prefix but copy/keep the rest */ + desc_new->group_name_prefix = mangle_identifier_ifneeded(desc_new, desc->group_name_prefix); + desc_new->group_description = desc->group_description; + desc_new->class_id = desc->class_id; + desc_new->num_ctr = desc->num_ctr; + desc_new->ctr_desc = talloc_array(desc_new, struct rate_ctr_desc, desc_new->num_ctr); + OSMO_ASSERT(desc_new->ctr_desc); + + for (i = 0; i < desc->num_ctr; i++) { + struct rate_ctr_desc *ctrd_new = (struct rate_ctr_desc *) desc_new->ctr_desc; + const struct rate_ctr_desc *ctrd = desc->ctr_desc; + + if (!ctrd[i].name) { + LOGP(DLGLOBAL, LOGL_ERROR, "counter group '%s'[%d] == NULL, aborting\n", + desc->group_name_prefix, i); + goto err_free; + } + + ctrd_new[i].name = mangle_identifier_ifneeded(desc_new->ctr_desc, ctrd[i].name); + ctrd_new[i].description = ctrd[i].description; + } + + if (!rate_ctrl_group_desc_validate(desc_new)) { + /* simple mangling of identifiers ('.' -> ':') was not sufficient to render a valid + * descriptor, we have to bail out */ + LOGP(DLGLOBAL, LOGL_ERROR, "counter group '%s' still invalid after mangling\n", + desc->group_name_prefix); + goto err_free; + } + + return desc_new; +err_free: + talloc_free(desc_new); + return NULL; +} + +/*! Find an unused index for this rate counter group. + * \param[in] name Name of the counter group + * \returns the largest used index number + 1, or 0 if none exist yet. */ +static unsigned int rate_ctr_get_unused_name_idx(const char *name) +{ + unsigned int idx = 0; + struct rate_ctr_group *ctrg; + + llist_for_each_entry(ctrg, &rate_ctr_groups, list) { + if (!ctrg->desc) + continue; + + if (strcmp(ctrg->desc->group_name_prefix, name)) + continue; + + if (idx <= ctrg->idx) + idx = ctrg->idx + 1; + } + return idx; +} + +/*! Allocate a new group of counters according to description + * \param[in] ctx parent talloc context + * \param[in] desc Rate counter group description + * \param[in] idx Index of new counter group + */ +struct rate_ctr_group *rate_ctr_group_alloc(void *ctx, + const struct rate_ctr_group_desc *desc, + unsigned int idx) +{ + unsigned int size; + struct rate_ctr_group *group; + + if (rate_ctr_get_group_by_name_idx(desc->group_name_prefix, idx)) { + unsigned int new_idx = rate_ctr_get_unused_name_idx(desc->group_name_prefix); + LOGP(DLGLOBAL, LOGL_ERROR, "counter group '%s' already exists for index %u," + " instead using index %u. This is a software bug that needs fixing.\n", + desc->group_name_prefix, idx, new_idx); + idx = new_idx; + } + + size = sizeof(struct rate_ctr_group) + + desc->num_ctr * sizeof(struct rate_ctr); + + if (!ctx) + ctx = tall_rate_ctr_ctx; + + group = talloc_zero_size(ctx, size); + if (!group) + return NULL; + + /* attempt to mangle all '.' in identifiers to ':' for backwards compat */ + if (!rate_ctrl_group_desc_validate(desc)) { + desc = rate_ctr_group_desc_mangle(group, desc); + if (!desc) { + talloc_free(group); + return NULL; + } + } + + group->desc = desc; + group->idx = idx; + + llist_add(&group->list, &rate_ctr_groups); + + return group; +} + +/*! Free the memory for the specified group of counters */ +void rate_ctr_group_free(struct rate_ctr_group *grp) +{ + if (!grp) + return; + + if (!llist_empty(&grp->list)) + llist_del(&grp->list); + talloc_free(grp); +} + +/*! Get rate counter from group, identified by index idx + * \param[in] grp Rate counter group + * \param[in] idx Index of the counter to retrieve + * \returns rate counter requested + */ +struct rate_ctr *rate_ctr_group_get_ctr(struct rate_ctr_group *grp, unsigned int idx) +{ + return &grp->ctr[idx]; +} + +/*! Set a name for the group of counters be used instead of index value + at report time. + * \param[in] grp Rate counter group + * \param[in] name Name identifier to assign to the rate counter group + */ +void rate_ctr_group_set_name(struct rate_ctr_group *grp, const char *name) +{ + osmo_talloc_replace_string(grp, &grp->name, name); +} + +/*! Add a number to the counter */ +void rate_ctr_add(struct rate_ctr *ctr, int inc) +{ + ctr->current += inc; +} + +/*! Return the counter difference since the last call to this function */ +int64_t rate_ctr_difference(struct rate_ctr *ctr) +{ + int64_t result = ctr->current - ctr->previous; + ctr->previous = ctr->current; + + return result; +} + +/* TODO: support update intervals > 1s */ +/* TODO: implement this as a special stats reporter */ + +static void interval_expired(struct rate_ctr *ctr, enum rate_ctr_intv intv) +{ + /* calculate rate over last interval */ + ctr->intv[intv].rate = ctr->current - ctr->intv[intv].last; + /* save current counter for next interval */ + ctr->intv[intv].last = ctr->current; +} + +static struct osmo_fd rate_ctr_timer = { .fd = -1 }; +static uint64_t timer_ticks; + +/* The one-second interval has expired */ +static void rate_ctr_group_intv(struct rate_ctr_group *grp) +{ + unsigned int i; + + for (i = 0; i < grp->desc->num_ctr; i++) { + struct rate_ctr *ctr = &grp->ctr[i]; + + interval_expired(ctr, RATE_CTR_INTV_SEC); + if ((timer_ticks % 60) == 0) + interval_expired(ctr, RATE_CTR_INTV_MIN); + if ((timer_ticks % (60*60)) == 0) + interval_expired(ctr, RATE_CTR_INTV_HOUR); + if ((timer_ticks % (24*60*60)) == 0) + interval_expired(ctr, RATE_CTR_INTV_DAY); + } +} + +static int rate_ctr_timer_cb(struct osmo_fd *ofd, unsigned int what) +{ + struct rate_ctr_group *ctrg; + uint64_t expire_count; + int rc; + + /* check that the timer has actually expired */ + if (!(what & OSMO_FD_READ)) + return 0; + + /* read from timerfd: number of expirations of periodic timer */ + rc = read(ofd->fd, (void *) &expire_count, sizeof(expire_count)); + if (rc < 0 && errno == EAGAIN) + return 0; + + OSMO_ASSERT(rc == sizeof(expire_count)); + + if (expire_count > 1) + LOGP(DLGLOBAL, LOGL_NOTICE, "Stats timer expire_count=%" PRIu64 ": We missed %" PRIu64 " timers\n", + expire_count, expire_count - 1); + + do { /* Increment number of ticks before we calculate intervals, + * as a counter value of 0 would already wrap all counters */ + timer_ticks++; + llist_for_each_entry(ctrg, &rate_ctr_groups, list) + rate_ctr_group_intv(ctrg); + } while (--expire_count); + + return 0; +} + +/*! Initialize the counter module. Call this once from your application. + * \param[in] tall_ctx Talloc context from which rate_ctr_group will be allocated + * \returns 0 on success; negative on error */ +int rate_ctr_init(void *tall_ctx) +{ + struct timespec ts_interval = { .tv_sec = 1, .tv_nsec = 0 }; + int rc; + + /* ignore repeated initialization */ + if (osmo_fd_is_registered(&rate_ctr_timer)) + return 0; + + tall_rate_ctr_ctx = tall_ctx; + + rc = osmo_timerfd_setup(&rate_ctr_timer, rate_ctr_timer_cb, NULL); + if (rc < 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "Failed to setup the timer with error code %d (fd=%d)\n", + rc, rate_ctr_timer.fd); + return rc; + } + + rc = osmo_timerfd_schedule(&rate_ctr_timer, NULL, &ts_interval); + if (rc < 0) { + LOGP(DLGLOBAL, LOGL_ERROR, "Failed to schedule the timer with error code %d (fd=%d)\n", + rc, rate_ctr_timer.fd); + } + + return 0; +} + +/*! Search for counter group based on group name and index + * \param[in] name Name of the counter group you're looking for + * \param[in] idx Index inside the counter group + * \returns \ref rate_ctr_group or NULL in case of error */ +struct rate_ctr_group *rate_ctr_get_group_by_name_idx(const char *name, const unsigned int idx) +{ + struct rate_ctr_group *ctrg; + + llist_for_each_entry(ctrg, &rate_ctr_groups, list) { + if (!ctrg->desc) + continue; + + if (!strcmp(ctrg->desc->group_name_prefix, name) && + ctrg->idx == idx) { + return ctrg; + } + } + return NULL; +} + +/*! Search for counter based on group + name + * \param[in] ctrg pointer to \ref rate_ctr_group + * \param[in] name name of counter inside group + * \returns \ref rate_ctr or NULL in case of error + */ +const struct rate_ctr *rate_ctr_get_by_name(const struct rate_ctr_group *ctrg, const char *name) +{ + int i; + const struct rate_ctr_desc *ctr_desc; + + if (!ctrg->desc) + return NULL; + + for (i = 0; i < ctrg->desc->num_ctr; i++) { + ctr_desc = &ctrg->desc->ctr_desc[i]; + + if (!strcmp(ctr_desc->name, name)) { + return &ctrg->ctr[i]; + } + } + return NULL; +} + +/*! Iterate over each counter in group and call function + * \param[in] ctrg counter group over which to iterate + * \param[in] handle_counter function pointer + * \param[in] data Data to hand transparently to handle_counter() + * \returns 0 on success; negative otherwise + */ +int rate_ctr_for_each_counter(struct rate_ctr_group *ctrg, + rate_ctr_handler_t handle_counter, void *data) +{ + int rc = 0; + int i; + + for (i = 0; i < ctrg->desc->num_ctr; i++) { + struct rate_ctr *ctr = &ctrg->ctr[i]; + rc = handle_counter(ctrg, + ctr, &ctrg->desc->ctr_desc[i], data); + if (rc < 0) + return rc; + } + + return rc; +} + +/*! Iterate over all counter groups + * \param[in] handle_group function pointer of callback function + * \param[in] data Data to hand transparently to handle_group() + * \returns 0 on success; negative otherwise + */ +int rate_ctr_for_each_group(rate_ctr_group_handler_t handle_group, void *data) +{ + struct rate_ctr_group *statg; + int rc = 0; + + llist_for_each_entry(statg, &rate_ctr_groups, list) { + rc = handle_group(statg, data); + if (rc < 0) + return rc; + } + + return rc; +} + +/*! Reset a rate counter back to zero + * \param[in] ctr counter to reset + */ +void rate_ctr_reset(struct rate_ctr *ctr) +{ + memset(ctr, 0, sizeof(*ctr)); +} + +/*! Reset all counters in a group + * \param[in] ctrg counter group to reset + */ +void rate_ctr_group_reset(struct rate_ctr_group *ctrg) +{ + int i; + + for (i = 0; i < ctrg->desc->num_ctr; i++) { + struct rate_ctr *ctr = &ctrg->ctr[i]; + rate_ctr_reset(ctr); + } +} + +/*! @} */ |