tidy up loop control and mutex

load/load_windows.go

@@ -35,28 +35,21 @@ func loadAvgGoroutine() {
 	)
 
 	counter, err := common.ProcessorQueueLengthCounter()
-	loadErr = err
 	if err != nil || counter == nil {
-		loadAvgMutex.Unlock()
-		log.Println("unexpected processor queue length counter error, please file an issue on github")
+		log.Println("gopsutil: unexpected processor queue length counter error, please file an issue on github")
 		return
 	}
 
 	tick := time.NewTicker(samplingFrequency).C
 	for {
-		currentLoad, loadErr = counter.GetValue()
-		if loadErr != nil {
-			goto SKIP
-		}
-
+		currentLoad, err = counter.GetValue()
+		loadAvgMutex.Lock()
+		loadErr = err
 		loadAvg1M = loadAvg1M*loadAvgFactor1M + currentLoad*(1-loadAvgFactor1M)
 		loadAvg5M = loadAvg5M*loadAvgFactor5M + currentLoad*(1-loadAvgFactor5M)
 		loadAvg15M = loadAvg15M*loadAvgFactor15M + currentLoad*(1-loadAvgFactor15M)
-
-	SKIP:
 		loadAvgMutex.Unlock()
 		<-tick
-		loadAvgMutex.Lock()
 	}
 }
 
@@ -67,7 +60,6 @@ func Avg() (*AvgStat, error) {
 
 func AvgWithContext(ctx context.Context) (*AvgStat, error) {
 	loadAvgGoroutineOnce.Do(func() {
-		loadAvgMutex.Lock() // lock to be unlocked by loadAvgGoroutine
 		go loadAvgGoroutine()
 	})
 	loadAvgMutex.RLock()