commit f0f7df1b87c0c82fe39e543bf6c6e432c627218d
author Stefan Sperling <ssperling@sysmocom.de> Fri May 25 15:12:30 2018 +0200
committer Harald Welte <laforge@gnumonks.org> Fri May 25 17:33:06 2018 +0000
tree f0197e16e99afdaf11decf0a678059f0fd62de60
parent 143b2da4f846acdcfccc9f1038d25f8a244a47de

read monotonic clock with clock_gettime() instead of gettimeofday()

There have been test failures on the osmo-pcu Jenkins builders due
to apparent clock drift. Switch relevant code from gettimeofday()
to clock_gettime() with CLOCK_MONOTONIC to prevent time from going
backwards and causing negative time deltas in calculations.

Change-Id: I775d85d0d3ac740330879e588bdab6fce7f0b46c
Related: OS#3225

src/gprs_rlcmac_meas.cpp

diff --git a/src/gprs_rlcmac_meas.cpp b/src/gprs_rlcmac_meas.cpp
index 41a7531..ac01f2a 100644
--- a/src/gprs_rlcmac_meas.cpp
+++ b/src/gprs_rlcmac_meas.cpp
@@ -71,22 +71,22 @@
 /* RSSI values received from MS */
 int gprs_rlcmac_rssi(struct gprs_rlcmac_tbf *tbf, int8_t rssi)
 {
-	struct timeval now_tv, *rssi_tv = &tbf->meas.rssi_tv;
+	struct timespec now_tv, *rssi_tv = &tbf->meas.rssi_tv;
 	uint32_t elapsed;
 
 	tbf->meas.rssi_sum += rssi;
 	tbf->meas.rssi_num++;
 
-	gettimeofday(&now_tv, NULL);
+	osmo_clock_gettime(CLOCK_MONOTONIC, &now_tv);
 	elapsed = ((now_tv.tv_sec - rssi_tv->tv_sec) << 7)
-		+ ((now_tv.tv_usec - rssi_tv->tv_usec) << 7) / 1000000;
+		+ (((now_tv.tv_nsec - rssi_tv->tv_nsec)/1000) << 7) / 1000000;
 	if (elapsed < 128)
 		return 0;
 
 	gprs_rlcmac_rssi_rep(tbf);
 
 	/* reset rssi values and timestamp */
-	memcpy(rssi_tv, &now_tv, sizeof(struct timeval));
+	memcpy(rssi_tv, &now_tv, sizeof(*rssi_tv));
 	tbf->meas.rssi_sum = 0;
 	tbf->meas.rssi_num = 0;
 
@@ -115,7 +115,7 @@
 int gprs_rlcmac_received_lost(struct gprs_rlcmac_dl_tbf *tbf, uint16_t received,
 	uint16_t lost)
 {
-	struct timeval now_tv, *loss_tv = &tbf->m_bw.dl_loss_tv;
+	struct timespec now_tv, *loss_tv = &tbf->m_bw.dl_loss_tv;
 	uint32_t elapsed;
 	uint16_t sum = received + lost;
 
@@ -129,16 +129,16 @@
 	tbf->m_bw.dl_loss_received += received;
 	tbf->m_bw.dl_loss_lost += lost;
 
-	gettimeofday(&now_tv, NULL);
+	osmo_clock_gettime(CLOCK_MONOTONIC, &now_tv);
 	elapsed = ((now_tv.tv_sec - loss_tv->tv_sec) << 7)
-		+ ((now_tv.tv_usec - loss_tv->tv_usec) << 7) / 1000000;
+		+ (((now_tv.tv_nsec - loss_tv->tv_nsec)/1000) << 7) / 1000000;
 	if (elapsed < 128)
 		return 0;
 
 	gprs_rlcmac_lost_rep(tbf);
 
 	/* reset lost values and timestamp */
-	memcpy(loss_tv, &now_tv, sizeof(struct timeval));
+	memcpy(loss_tv, &now_tv, sizeof(*loss_tv));
 	tbf->m_bw.dl_loss_received = 0;
 	tbf->m_bw.dl_loss_lost = 0;
 
@@ -168,14 +168,14 @@
 
 int gprs_rlcmac_dl_bw(struct gprs_rlcmac_dl_tbf *tbf, uint16_t octets)
 {
-	struct timeval now_tv, *bw_tv = &tbf->m_bw.dl_bw_tv;
+	struct timespec now_tv, *bw_tv = &tbf->m_bw.dl_bw_tv;
 	uint32_t elapsed;
 
 	tbf->m_bw.dl_bw_octets += octets;
 
-	gettimeofday(&now_tv, NULL);
+	osmo_clock_gettime(CLOCK_MONOTONIC, &now_tv);
 	elapsed = ((now_tv.tv_sec - bw_tv->tv_sec) << 7)
-		+ ((now_tv.tv_usec - bw_tv->tv_usec) << 7) / 1000000;
+		+ (((now_tv.tv_nsec - bw_tv->tv_nsec)/1000) << 7) / 1000000;
 	if (elapsed < 128)
 		return 0;
 
@@ -186,7 +186,7 @@
 		tbf->m_bw.dl_bw_octets / elapsed);
 
 	/* reset bandwidth values timestamp */
-	memcpy(bw_tv, &now_tv, sizeof(struct timeval));
+	memcpy(bw_tv, &now_tv, sizeof(*bw_tv));
 	tbf->m_bw.dl_bw_octets = 0;
 
 	return 0;