fix time-delta calculations for measurement reports
The previous implementation unconditionally subtracted nanosecond
values from different time measurements, causing overflow if the
current measurement was taken in less of a fraction of a second
than the past measurement. Use timespecsub() instead, which
accounts for nanoseconds correctly.
Also, fix calculations of KBit/s throughtput. It was not being
calculated correctly, since it was actually accounting for one
KB per 128th-part-of-a-second.
Change-Id: I7d22e7b5902c230efeae66eb20c17026a4037887
Related: OS#3225
diff --git a/src/gprs_rlcmac_meas.cpp b/src/gprs_rlcmac_meas.cpp
index ac01f2a..cffdbc6 100644
--- a/src/gprs_rlcmac_meas.cpp
+++ b/src/gprs_rlcmac_meas.cpp
@@ -17,6 +17,8 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
+#include <osmocom/core/timer_compat.h>
+
#include <gprs_rlcmac.h>
#include <gprs_debug.h>
#include <pcu_l1_if.h>
@@ -72,15 +74,15 @@
int gprs_rlcmac_rssi(struct gprs_rlcmac_tbf *tbf, int8_t rssi)
{
struct timespec now_tv, *rssi_tv = &tbf->meas.rssi_tv;
- uint32_t elapsed;
+ struct timespec elapsed;
tbf->meas.rssi_sum += rssi;
tbf->meas.rssi_num++;
osmo_clock_gettime(CLOCK_MONOTONIC, &now_tv);
- elapsed = ((now_tv.tv_sec - rssi_tv->tv_sec) << 7)
- + (((now_tv.tv_nsec - rssi_tv->tv_nsec)/1000) << 7) / 1000000;
- if (elapsed < 128)
+
+ timespecsub(&now_tv, rssi_tv, &elapsed);
+ if (elapsed.tv_sec < 1)
return 0;
gprs_rlcmac_rssi_rep(tbf);
@@ -116,7 +118,7 @@
uint16_t lost)
{
struct timespec now_tv, *loss_tv = &tbf->m_bw.dl_loss_tv;
- uint32_t elapsed;
+ struct timespec elapsed;
uint16_t sum = received + lost;
/* No measurement values */
@@ -129,10 +131,8 @@
tbf->m_bw.dl_loss_received += received;
tbf->m_bw.dl_loss_lost += lost;
- osmo_clock_gettime(CLOCK_MONOTONIC, &now_tv);
- elapsed = ((now_tv.tv_sec - loss_tv->tv_sec) << 7)
- + (((now_tv.tv_nsec - loss_tv->tv_nsec)/1000) << 7) / 1000000;
- if (elapsed < 128)
+ timespecsub(&now_tv, loss_tv, &elapsed);
+ if (elapsed.tv_sec < 1)
return 0;
gprs_rlcmac_lost_rep(tbf);
@@ -169,21 +169,18 @@
int gprs_rlcmac_dl_bw(struct gprs_rlcmac_dl_tbf *tbf, uint16_t octets)
{
struct timespec now_tv, *bw_tv = &tbf->m_bw.dl_bw_tv;
- uint32_t elapsed;
+ struct timespec elapsed;
tbf->m_bw.dl_bw_octets += octets;
osmo_clock_gettime(CLOCK_MONOTONIC, &now_tv);
- elapsed = ((now_tv.tv_sec - bw_tv->tv_sec) << 7)
- + (((now_tv.tv_nsec - bw_tv->tv_nsec)/1000) << 7) / 1000000;
- if (elapsed < 128)
+ timespecsub(&now_tv, bw_tv, &elapsed);
+ if (elapsed.tv_sec < 1)
return 0;
- tbf->m_bw.dl_throughput = (tbf->m_bw.dl_bw_octets/elapsed);
-
+ tbf->m_bw.dl_throughput = (tbf->m_bw.dl_bw_octets << 10) / ((elapsed.tv_sec << 10) + (elapsed.tv_nsec >> 20));
LOGP(DRLCMACMEAS, LOGL_INFO, "DL Bandwitdh of IMSI=%s / TLLI=0x%08x: "
- "%d KBits/s\n", tbf->imsi(), tbf->tlli(),
- tbf->m_bw.dl_bw_octets / elapsed);
+ "%d KBits/s\n", tbf->imsi(), tbf->tlli(), tbf->m_bw.dl_throughput);
/* reset bandwidth values timestamp */
memcpy(bw_tv, &now_tv, sizeof(*bw_tv));