From 3180afc331b09b45c3cec0d96e7176c8ac5eff65 Mon Sep 17 00:00:00 2001
From: Mike Brady <4265913+mikebrady@users.noreply.github.com>
Date: Sun, 28 Nov 2021 16:05:49 +0000
Subject: [PATCH] Move to using CLOCK_MONOLITHIC_RAW to avoid NTP effects.
 Increase bias towards positive jitter changes. Bump interface version.

---
 general-utilities.c      | 2 +-
 nqptp-message-handlers.c | 4 ++--
 nqptp-shm-structures.h   | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/general-utilities.c b/general-utilities.c
index 1a89578..6af2977 100644
--- a/general-utilities.c
+++ b/general-utilities.c
@@ -66,6 +66,6 @@ uint64_t timespec_to_ns(struct timespec *tn) {
 
 uint64_t get_time_now() {
   struct timespec tn;
-  clock_gettime(CLOCK_REALTIME, &tn); // this should be optionally CLOCK_MONOTONIC etc.
+  clock_gettime(CLOCK_MONOTONIC_RAW, &tn);
   return timespec_to_ns(&tn);
 }
diff --git a/nqptp-message-handlers.c b/nqptp-message-handlers.c
index 562a57e..1637111 100644
--- a/nqptp-message-handlers.c
+++ b/nqptp-message-handlers.c
@@ -387,11 +387,11 @@ void handle_follow_up(char *buf, __attribute__((unused)) ssize_t recv_len,
       if (jitter > -10000000) {
         // we take any positive or a limited negative jitter as a sync event
         if (jitter < 0)
-          offset = clock_private_info->previous_offset + jitter / 16;
+          offset = clock_private_info->previous_offset + jitter / 32;
         else if (clock_private_info->follow_up_number < (5 * 8)) // at the beginning (8 samples per second)
           offset = clock_private_info->previous_offset + jitter / 2; // accept positive changes quickly
         else
-          offset = clock_private_info->previous_offset + jitter / 16;
+          offset = clock_private_info->previous_offset + jitter / 2;
         clock_private_info->last_sync_time = reception_time;
       } else {
         offset = clock_private_info->previous_offset; // forget the present sample...
diff --git a/nqptp-shm-structures.h b/nqptp-shm-structures.h
index 36c8a81..f4db8c6 100644
--- a/nqptp-shm-structures.h
+++ b/nqptp-shm-structures.h
@@ -22,7 +22,7 @@
 
 #define STORAGE_ID "/nqptp"
 #define MAX_CLOCKS 32
-#define NQPTP_SHM_STRUCTURES_VERSION 5
+#define NQPTP_SHM_STRUCTURES_VERSION 6
 #define NQPTP_CONTROL_PORT 9000
 
 // the control port will accept a UDP packet with the first letter being:
-- 
2.47.2