From fb162ff529883049605a403ce239c34a83e24746 Mon Sep 17 00:00:00 2001
From: Jakob Borg <jakob@nym.se>
Date: Mon, 14 Apr 2014 12:02:40 +0200
Subject: [PATCH] More up to date CPU usage indicator

---
 cmd/syncthing/gui.go         | 8 ++++++--
 cmd/syncthing/gui_solaris.go | 6 +++---
 cmd/syncthing/gui_unix.go    | 6 +++---
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/cmd/syncthing/gui.go b/cmd/syncthing/gui.go
index 603a633dd..41e279b5a 100644
--- a/cmd/syncthing/gui.go
+++ b/cmd/syncthing/gui.go
@@ -155,7 +155,7 @@ func restGetNeed(m *Model, w http.ResponseWriter, params martini.Params) {
 	json.NewEncoder(w).Encode(gfs)
 }
 
-var cpuUsagePercent float64
+var cpuUsagePercent [10]float64 // The last ten seconds
 var cpuUsageLock sync.RWMutex
 
 func restGetSystem(w http.ResponseWriter) {
@@ -168,8 +168,12 @@ func restGetSystem(w http.ResponseWriter) {
 	res["alloc"] = m.Alloc
 	res["sys"] = m.Sys
 	cpuUsageLock.RLock()
-	res["cpuPercent"] = cpuUsagePercent
+	var cpusum float64
+	for _, p := range cpuUsagePercent {
+		cpusum += p
+	}
 	cpuUsageLock.RUnlock()
+	res["cpuPercent"] = cpusum / 10
 
 	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(res)
diff --git a/cmd/syncthing/gui_solaris.go b/cmd/syncthing/gui_solaris.go
index 48f787c72..fa53efe98 100644
--- a/cmd/syncthing/gui_solaris.go
+++ b/cmd/syncthing/gui_solaris.go
@@ -72,8 +72,7 @@ func trackCPUUsage() {
 	var prevTime = time.Now().UnixNano()
 	var rusage prusage_t
 	var pid = os.Getpid()
-	for {
-		time.Sleep(10 * time.Second)
+	for _ = range time.NewTicker(time.Second).C {
 		err := solarisPrusage(pid, &rusage)
 		if err != nil {
 			warnln(err)
@@ -84,7 +83,8 @@ func trackCPUUsage() {
 		curUsage := rusage.Pr_utime.Nano() + rusage.Pr_stime.Nano()
 		usageDiff := curUsage - prevUsage
 		cpuUsageLock.Lock()
-		cpuUsagePercent = 100 * float64(usageDiff) / float64(timeDiff)
+		copy(cpuUsagePercent[1:], cpuUsagePercent[0:])
+		cpuUsagePercent[0] = 100 * float64(usageDiff) / float64(timeDiff)
 		cpuUsageLock.Unlock()
 		prevTime = curTime
 		prevUsage = curUsage
diff --git a/cmd/syncthing/gui_unix.go b/cmd/syncthing/gui_unix.go
index f9d8e52a7..9d463e498 100644
--- a/cmd/syncthing/gui_unix.go
+++ b/cmd/syncthing/gui_unix.go
@@ -15,15 +15,15 @@ func trackCPUUsage() {
 	var prevUsage int64
 	var prevTime = time.Now().UnixNano()
 	var rusage syscall.Rusage
-	for {
-		time.Sleep(10 * time.Second)
+	for _ = range time.NewTicker(time.Second).C {
 		syscall.Getrusage(syscall.RUSAGE_SELF, &rusage)
 		curTime := time.Now().UnixNano()
 		timeDiff := curTime - prevTime
 		curUsage := rusage.Utime.Nano() + rusage.Stime.Nano()
 		usageDiff := curUsage - prevUsage
 		cpuUsageLock.Lock()
-		cpuUsagePercent = 100 * float64(usageDiff) / float64(timeDiff)
+		copy(cpuUsagePercent[1:], cpuUsagePercent[0:])
+		cpuUsagePercent[0] = 100 * float64(usageDiff) / float64(timeDiff)
 		cpuUsageLock.Unlock()
 		prevTime = curTime
 		prevUsage = curUsage