rate_ctr: convert to timerfd
Use timerfd to schedule 1-second periodic timer once
instead rescheduling every second in timer callback.
Related: OS#5671
Change-Id: I2525fd691caa380a862d305cfcb4fa3cc50b70d0
diff --git a/src/rate_ctr.c b/src/rate_ctr.c
index ffae1b8..3fc4992 100644
--- a/src/rate_ctr.c
+++ b/src/rate_ctr.c
@@ -53,14 +53,17 @@
*
* \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/timer.h>
+#include <osmocom/core/select.h>
#include <osmocom/core/rate_ctr.h>
#include <osmocom/core/logging.h>
@@ -310,7 +313,7 @@
ctr->intv[intv+1].rate += ctr->intv[intv].rate;
}
-static struct osmo_timer_list rate_ctr_timer;
+static struct osmo_fd rate_ctr_timer = { .fd = -1 };
static uint64_t timer_ticks;
/* The one-second interval has expired */
@@ -331,18 +334,35 @@
}
}
-static void rate_ctr_timer_cb(void *data)
+static int rate_ctr_timer_cb(struct osmo_fd *ofd, unsigned int what)
{
struct rate_ctr_group *ctrg;
+ uint64_t expire_count;
+ int rc;
- /* Increment number of ticks before we calculate intervals,
- * as a counter value of 0 would already wrap all counters */
- timer_ticks++;
+ /* check that the timer has actually expired */
+ if (!(what & OSMO_FD_READ))
+ return 0;
- llist_for_each_entry(ctrg, &rate_ctr_groups, list)
- rate_ctr_group_intv(ctrg);
+ /* 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_timer_schedule(&rate_ctr_timer, 1, 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.
@@ -350,13 +370,27 @@
* \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_timer_pending(&rate_ctr_timer))
+ if (osmo_fd_is_registered(&rate_ctr_timer))
return 0;
tall_rate_ctr_ctx = tall_ctx;
- osmo_timer_setup(&rate_ctr_timer, rate_ctr_timer_cb, NULL);
- osmo_timer_schedule(&rate_ctr_timer, 1, 0);
+
+ 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;
}