From afcb81927e773c6a44d038352f1592a54b7d4101 Mon Sep 17 00:00:00 2001
From: Dirk Zimoch <dirk.zimoch@psi.ch>
Date: Thu, 29 Mar 2018 13:32:27 +0200
Subject: [PATCH] catch tNTP time jumps in vxWorks

---
 src/libCom/osi/osiNTPTime.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/libCom/osi/osiNTPTime.c b/src/libCom/osi/osiNTPTime.c
index 909e6f121..0997cc42e 100644
--- a/src/libCom/osi/osiNTPTime.c
+++ b/src/libCom/osi/osiNTPTime.c
@@ -177,6 +177,19 @@ static void NTPTimeSync(void *dummy)
             continue;
         }
 
+        if (ntpDelta > 3600 && NTPTimePvt.synchronized) {
+            char nowTimeText[32];
+            char ntpTimeText[32];
+            epicsTimeToStrftime(ntpTimeText,sizeof(nowTimeText),"%Y-%m-%d %H:%M:%S.%09f",
+                &NTPTimePvt.syncTime);
+            epicsTimeToStrftime(ntpTimeText,sizeof(ntpTimeText),"%Y-%m-%d %H:%M:%S.%09f",
+                &timeNow);
+            errlogPrintf("NTPTimeSync: refuse to jump from %s to future %s (timespec: %li.%09li)\n",
+                nowTimeText, ntpTimeText, timespecNow.tv_sec, timespecNow.tv_nsec);
+            NTPTimePvt.synchronized = 0;
+            continue;
+        }
+
         NTPTimePvt.syncsFailed = 0;
         if (!NTPTimePvt.synchronized) {
             errlogPrintf("NTPTimeSync: Sync recovered.\n");
@@ -274,6 +287,8 @@ int NTPTime_Report(int level)
                 osdTickRateGet());
             printf("Measured tick rate = %.3f Hz\n",
                 NTPTimePvt.tickRate);
+            printf("Ticks to skip = %d ticks\n",
+                NTPTimePvt.ticksToSkip);
             osdNTPReport();
         }
     } else {