Sleep causes a tenfold difference in time interval

[尚义龙]

I was doing pressure testing in my project and found a large gap in the time interval due to time.Sleep, which I abstracted to the following code:

code 1:

```go

func TestSleep(t *testing.T) {

for i := 0; i < 8; i++ {

//time.Sleep(time.Second)

t1 := time.Now()

fmt.Println( time.Since(t1))

}

}

```

output:

```shell

229ns

37ns

36ns

37ns

36ns

38ns

37ns

39ns

```

code 2(add time.Sleep):

```

func TestSleep(t *testing.T) {

for i := 0; i < 8; i++ {

time.Sleep(time.Second)

t1 := time.Now()

fmt.Println( time.Since(t1))

}

}

```

```shell

471ns

267ns

855ns

484ns

359ns

296ns

324ns

302ns

```

I have two questions:

1. Why is there such a big difference between the two results (only the time.Sleep difference)?

2. Why is the first output in code1 much larger than the next?

please.

[Robert Engels]

Because when you sleep you deschedule the process/thread by the OS - and so the cached code and data needs to be reloaded so operations aren’t slower until then. 

On Nov 4, 2021, at 11:19 AM, 尚义龙 <sylh...@gmail.com> wrote:



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