1 files changed, 32 insertions, 0 deletions
diff --git a/weed/udptransfer/timing_test.go b/weed/udptransfer/timing_test.go
new file mode 100644
index 000000000..4f73bc33a
--- /dev/null
+++ b/weed/udptransfer/timing_test.go
@@ -0,0 +1,32 @@
+package udptransfer
+
+import (
+	"math"
+	"testing"
+	"time"
+)
+
+func Test_sleep(t *testing.T) {
+	const loops = 10
+	var intervals = [...]int64{1, 1e3, 1e4, 1e5, 1e6, 1e7}
+	var ret [len(intervals)][loops]int64
+	for j := 0; j < len(intervals); j++ {
+		v := time.Duration(intervals[j])
+		for i := 0; i < loops; i++ {
+			t0 := NowNS()
+			time.Sleep(v)
+			ret[j][i] = NowNS() - t0
+		}
+	}
+	for j := 0; j < len(intervals); j++ {
+		var exp, sum, stdev float64
+		exp = float64(intervals[j])
+		for _, v := range ret[j] {
+			sum += float64(v)
+			stdev += math.Pow(float64(v)-exp, 2)
+		}
+		stdev /= float64(loops)
+		stdev = math.Sqrt(stdev)
+		t.Logf("interval=%s sleeping=%s stdev/k=%.2f", time.Duration(intervals[j]), time.Duration(sum/loops), stdev/1e3)
+	}
+}