add load v2

tidied up common/windows
added load benchmark for load_test
cpu percent is used as load if queue is zero

internal/common/common_windows.go

@@ -142,44 +142,49 @@ func GetCounterValue(counter windows.Handle) (float64, error) {
 	return value.DoubleValue, nil
 }
 
-// ProcessorQueueLengthGenerator is struct of windows api
-// adapted from https://github.com/mackerelio/mackerel-agent/
-type ProcessorQueueLengthGenerator struct {
-	query   windows.Handle
-	counter *CounterInfo
+type Win32PerformanceCounter struct {
+	PostName    string
+	CounterName string
+	Query       windows.Handle
+	Counter     windows.Handle
 }
 
-// NewProcessorQueueLengthGenerator is set up windows api
-// adapted from https://github.com/mackerelio/mackerel-agent/
-func NewProcessorQueueLengthGenerator() (*ProcessorQueueLengthGenerator, error) {
-	g := &ProcessorQueueLengthGenerator{0, nil}
-
-	var err error
-	g.query, err = CreateQuery()
+func NewWin32PerformanceCounter(postName, counterName string) (*Win32PerformanceCounter, error) {
+	query, err := CreateQuery()
 	if err != nil {
 		return nil, err
 	}
-
-	counter, err := CreateCounter(g.query, "processor_queue_length", `\System\Processor Queue Length`)
-	if err != nil {
+	var counter = Win32PerformanceCounter{
+		Query:       query,
+		PostName:    postName,
+		CounterName: counterName,
+	}
+	r, _, err := PdhAddCounter.Call(
+		uintptr(counter.Query),
+		uintptr(unsafe.Pointer(windows.StringToUTF16Ptr(counter.CounterName))),
+		0,
+		uintptr(unsafe.Pointer(&counter.Counter)),
+	)
+	if r != 0 {
 		return nil, err
 	}
-	g.counter = counter
-	return g, nil
+	return &counter, nil
 }
 
-// Generate XXX
-// adapted from https://github.com/mackerelio/mackerel-agent/
-func (g *ProcessorQueueLengthGenerator) Generate() (float64, error) {
-	r, _, err := PdhCollectQueryData.Call(uintptr(g.query))
+func (w *Win32PerformanceCounter) GetValue() (float64, error) {
+	r, _, err := PdhCollectQueryData.Call(uintptr(w.Query))
 	if r != 0 && err != nil {
 		if r == PDH_NO_DATA {
-			return 0.0, fmt.Errorf("%w: this metric has not data", err)
+			return 0.0, fmt.Errorf("%w: this counter has not data", err)
 		}
 		return 0.0, err
 	}
 
-	return GetCounterValue(g.counter.Counter)
+	return GetCounterValue(w.Counter)
+}
+
+func ProcessorQueueLengthCounter() (*Win32PerformanceCounter, error) {
+	return NewWin32PerformanceCounter("processor_queue_length", `\System\Processor Queue Length`)
 }
 
 // WMIQueryWithContext - wraps wmi.Query with a timed-out context to avoid hanging

load/load_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/shirou/gopsutil/internal/common"
 )
 
-func skipIfNotImplementedErr(t *testing.T, err error) {
+func skipIfNotImplementedErr(t testing.TB, err error) {
 	if err == common.ErrNotImplementedError {
 		t.Skip("not implemented")
 	}
@@ -27,23 +27,6 @@ func TestLoad(t *testing.T) {
 	t.Log(v)
 }
 
-// Commented out to not to slow down CI
-// Do conduct heavy cpu load on he computer to observe change
-// func TestLoadWithInterval(t *testing.T) {
-// 	interval := 5
-// 	iteration := 110 / interval
-
-// 	for i := 0; i < iteration; i++ {
-// 		v, err := Avg()
-// 		skipIfNotImplementedErr(t, err)
-// 		if err != nil {
-// 			t.Errorf("error %v", err)
-// 		}
-// 		t.Log(v)
-// 		time.Sleep(time.Duration(interval) * time.Second)
-// 	}
-// }
-
 func TestLoadAvgStat_String(t *testing.T) {
 	v := AvgStat{
 		Load1:  10.1,
@@ -84,3 +67,28 @@ func TestMiscStatString(t *testing.T) {
 	}
 	t.Log(e)
 }
+
+func BenchmarkLoad(b *testing.B) {
+
+	loadAvg := func(t testing.TB) {
+		v, err := Avg()
+		skipIfNotImplementedErr(t, err)
+		if err != nil {
+			t.Errorf("error %v", err)
+		}
+		empty := &AvgStat{}
+		if v == empty {
+			t.Errorf("error load: %v", v)
+		}
+	}
+
+	b.Run("FirstCall", func(b *testing.B) {
+		loadAvg(b)
+	})
+
+	b.Run("SubsequentCalls", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			loadAvg(b)
+		}
+	})
+}

load/load_windows.go

@@ -4,9 +4,11 @@ package load
 
 import (
 	"context"
+	"log"
 	"sync"
 	"time"
 
+	"github.com/shirou/gopsutil/cpu"
 	"github.com/shirou/gopsutil/internal/common"
 )
 
@@ -31,30 +33,51 @@ func loadAvgGoroutine() {
 	)
 
 	var (
-		interval = 5 * time.Second
+		sleepInterval time.Duration = 5 * time.Second
+		currentLoad   float64
 	)
 
-	generator, err := common.NewProcessorQueueLengthGenerator()
-	if err != nil {
-		loadAvgMutex.Lock()
-		loadErr = err
+	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")
 		return
 	}
+
 	for {
-		time.Sleep(interval)
-		if generator == nil {
-			return
+		currentLoad, loadErr = counter.GetValue()
+		if loadErr != nil {
+			goto SKIP
 		}
-		currentLoad, err := generator.Generate()
-		loadAvgMutex.Lock()
-		loadErr = err
-		if err == nil {
-			loadAvg1M = loadAvg1M*loadAvgFactor1F + currentLoad*(1.0-loadAvgFactor1F)
-			loadAvg5M = loadAvg5M*loadAvgFactor5F + currentLoad*(1.0-loadAvgFactor5F)
-			loadAvg15M = loadAvg15M*loadAvgFactor15F + currentLoad*(1.0-loadAvgFactor15F)
+		// comment following block if you want load to be 0 as long as process queue is zero
+		{
+			if currentLoad == 0.0 {
+				percent, err := cpu.Percent(0, false)
+				if err == nil {
+					currentLoad = percent[0] / 100
+					// load averages are also given some amount of the currentLoad
+					// maybe they shouldnt?
+					if loadAvg1M == 0 {
+						loadAvg1M = currentLoad
+					}
+					if loadAvg5M == 0 {
+						loadAvg5M = currentLoad / 2
+					}
+					if loadAvg15M == 0 {
+						loadAvg15M = currentLoad / 3
+					}
+				}
+			}
 		}
+		loadAvg1M = loadAvg1M*loadAvgFactor1F + currentLoad*(1.0-loadAvgFactor1F)
+		loadAvg5M = loadAvg5M*loadAvgFactor5F + currentLoad*(1.0-loadAvgFactor5F)
+		loadAvg15M = loadAvg15M*loadAvgFactor15F + currentLoad*(1.0-loadAvgFactor15F)
+
+	SKIP:
 		loadAvgMutex.Unlock()
+		time.Sleep(sleepInterval)
+		loadAvgMutex.Lock()
 	}
 }
 
@@ -63,7 +86,10 @@ func Avg() (*AvgStat, error) {
 }
 
 func AvgWithContext(ctx context.Context) (*AvgStat, error) {
-	loadAvgGoroutineOnce.Do(func() { go loadAvgGoroutine() })
+	loadAvgGoroutineOnce.Do(func() {
+		loadAvgMutex.Lock()
+		go loadAvgGoroutine()
+	})
 	loadAvgMutex.RLock()
 	defer loadAvgMutex.RUnlock()
 	ret := AvgStat{