From 6303b0c5369532c398b23d810d803499a2522fb7 Mon Sep 17 00:00:00 2001
From: Christopher Young <cyoung@gmail.com>
Date: Thu, 7 Jan 2016 11:08:54 -0500
Subject: [PATCH] Use monotonic timer for uptime.

Fixes #69.
---
 main/gen_gdl90.go |  7 +++++--
 main/monotonic.go | 27 +++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)
 create mode 100644 main/monotonic.go

diff --git a/main/gen_gdl90.go b/main/gen_gdl90.go
index 9bc2c24f..c71f7695 100644
--- a/main/gen_gdl90.go
+++ b/main/gen_gdl90.go
@@ -717,7 +717,7 @@ func updateStatus() {
 	}
 
 	// Update Uptime value
-	globalStatus.Uptime = time.Since(timeStarted).Nanoseconds() / 1000000
+	globalStatus.Uptime = int64(stratuxClock.Seconds) * 1000
 }
 
 type ReplayWriter struct {
@@ -1109,7 +1109,7 @@ func printStats() {
 		<-statTimer.C
 		var memstats runtime.MemStats
 		runtime.ReadMemStats(&memstats)
-		log.Printf("stats [up since: %s]\n", humanize.Time(timeStarted))
+		log.Printf("stats [started: %s]\n", humanize.RelTime(time.Time{}, stratuxClock.Time, "ago", "from now"))
 		log.Printf(" - CPUTemp=%.02f deg C, MemStats.Alloc=%s, MemStats.Sys=%s, totalNetworkMessagesSent=%s\n", globalStatus.CPUTemp, humanize.Bytes(uint64(memstats.Alloc)), humanize.Bytes(uint64(memstats.Sys)), humanize.Comma(int64(totalNetworkMessagesSent)))
 		log.Printf(" - UAT/min %s/%s [maxSS=%.02f%%], ES/min %s/%s\n, Total traffic targets tracked=%s", humanize.Comma(int64(globalStatus.UAT_messages_last_minute)), humanize.Comma(int64(globalStatus.UAT_messages_max)), float64(maxSignalStrength)/10.0, humanize.Comma(int64(globalStatus.ES_messages_last_minute)), humanize.Comma(int64(globalStatus.ES_messages_max)), humanize.Comma(int64(len(seenTraffic))))
 		if globalSettings.GPS_Enabled {
@@ -1186,7 +1186,10 @@ func openReplayFile(fn string) ReadCloser {
 	return ret
 }
 
+var stratuxClock *monotonic
+
 func main() {
+	stratuxClock = NewMonotonic() // Start our "stratux clock".
 
 	//	replayESFilename := flag.String("eslog", "none", "ES Log filename")
 	replayUATFilename := flag.String("uatlog", "none", "UAT Log filename")
diff --git a/main/monotonic.go b/main/monotonic.go
new file mode 100644
index 00000000..026523e0
--- /dev/null
+++ b/main/monotonic.go
@@ -0,0 +1,27 @@
+package main
+
+import (
+	"time"
+)
+
+// Timer (since start).
+
+type monotonic struct {
+	Seconds uint64
+	Time    time.Time
+	ticker  *time.Ticker
+}
+
+func (m *monotonic) Watcher() {
+	for {
+		<-m.ticker.C
+		m.Seconds++
+		m.Time = m.Time.Add(1 * time.Second)
+	}
+}
+
+func NewMonotonic() *monotonic {
+	t := &monotonic{Seconds: 0, Time: time.Time{}, ticker: time.NewTicker(1 * time.Second)}
+	go t.Watcher()
+	return t
+}