Report CPU/mem usage in GUI

gui_unix.go

@@ -0,0 +1,31 @@
+//+build !windows
+
+package main
+
+import (
+	"syscall"
+	"time"
+)
+
+func init() {
+	go trackCPUUsage()
+}
+
+func trackCPUUsage() {
+	var prevUsage int64
+	var prevTime = time.Now().UnixNano()
+	var rusage syscall.Rusage
+	for {
+		time.Sleep(10 * time.Second)
+		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)
+		cpuUsageLock.Unlock()
+		prevTime = curTime
+		prevUsage = curUsage
+	}
+}