github.com/linapex/ethereum-go-chinese@v0.0.0-20190316121929-f8b7a73c3fa1/metrics/runtime_test.go (about)

     1  
     2  //<developer>
     3  //    <name>linapex 曹一峰</name>
     4  //    <email>linapex@163.com</email>
     5  //    <wx>superexc</wx>
     6  //    <qqgroup>128148617</qqgroup>
     7  //    <url>https://jsq.ink</url>
     8  //    <role>pku engineer</role>
     9  //    <date>2019-03-16 19:16:40</date>
    10  //</624450100025888768>
    11  
    12  package metrics
    13  
    14  import (
    15  	"runtime"
    16  	"testing"
    17  	"time"
    18  )
    19  
    20  func BenchmarkRuntimeMemStats(b *testing.B) {
    21  	r := NewRegistry()
    22  	RegisterRuntimeMemStats(r)
    23  	b.ResetTimer()
    24  	for i := 0; i < b.N; i++ {
    25  		CaptureRuntimeMemStatsOnce(r)
    26  	}
    27  }
    28  
    29  func TestRuntimeMemStats(t *testing.T) {
    30  	r := NewRegistry()
    31  	RegisterRuntimeMemStats(r)
    32  	CaptureRuntimeMemStatsOnce(r)
    33  zero := runtimeMetrics.MemStats.PauseNs.Count() //得到一个“零”，因为GC可能在这些测试之前运行。
    34  	runtime.GC()
    35  	CaptureRuntimeMemStatsOnce(r)
    36  	if count := runtimeMetrics.MemStats.PauseNs.Count(); 1 != count-zero {
    37  		t.Fatal(count - zero)
    38  	}
    39  	runtime.GC()
    40  	runtime.GC()
    41  	CaptureRuntimeMemStatsOnce(r)
    42  	if count := runtimeMetrics.MemStats.PauseNs.Count(); 3 != count-zero {
    43  		t.Fatal(count - zero)
    44  	}
    45  	for i := 0; i < 256; i++ {
    46  		runtime.GC()
    47  	}
    48  	CaptureRuntimeMemStatsOnce(r)
    49  	if count := runtimeMetrics.MemStats.PauseNs.Count(); 259 != count-zero {
    50  		t.Fatal(count - zero)
    51  	}
    52  	for i := 0; i < 257; i++ {
    53  		runtime.GC()
    54  	}
    55  	CaptureRuntimeMemStatsOnce(r)
    56  if count := runtimeMetrics.MemStats.PauseNs.Count(); 515 != count-zero { //我们丢失了一个，因为捕获之间的GCS太多了。
    57  		t.Fatal(count - zero)
    58  	}
    59  }
    60  
    61  func TestRuntimeMemStatsNumThread(t *testing.T) {
    62  	r := NewRegistry()
    63  	RegisterRuntimeMemStats(r)
    64  	CaptureRuntimeMemStatsOnce(r)
    65  
    66  	if value := runtimeMetrics.NumThread.Value(); value < 1 {
    67  		t.Fatalf("got NumThread: %d, wanted at least 1", value)
    68  	}
    69  }
    70  
    71  func TestRuntimeMemStatsBlocking(t *testing.T) {
    72  	if g := runtime.GOMAXPROCS(0); g < 2 {
    73  		t.Skipf("skipping TestRuntimeMemStatsBlocking with GOMAXPROCS=%d\n", g)
    74  	}
    75  	ch := make(chan int)
    76  	go testRuntimeMemStatsBlocking(ch)
    77  	var memStats runtime.MemStats
    78  	t0 := time.Now()
    79  	runtime.ReadMemStats(&memStats)
    80  	t1 := time.Now()
    81  	t.Log("i++ during runtime.ReadMemStats:", <-ch)
    82  	go testRuntimeMemStatsBlocking(ch)
    83  	d := t1.Sub(t0)
    84  	t.Log(d)
    85  	time.Sleep(d)
    86  	t.Log("i++ during time.Sleep:", <-ch)
    87  }
    88  
    89  func testRuntimeMemStatsBlocking(ch chan int) {
    90  	i := 0
    91  	for {
    92  		select {
    93  		case ch <- i:
    94  			return
    95  		default:
    96  			i++
    97  		}
    98  	}
    99  }
   100