如何使超时功能更好

Question

I was using time.After(time), which is working OK.

My question is: Is it precise and should I use this or should I make my own function? I am using this with a Raft Consensus algorithm implementation.

Answer 1

I presume you mean time.After?

I wrote a quick benchmark to answer this question.

Run with go test -run XXX -bench . time_after_test.go

package main

import (
    "testing"
    "time"
)

func BenchmarkTimeAfterSecond(b *testing.B) {
    for i := 0; i < b.N; i++ {
        <-time.After(time.Second)
    }
}

func BenchmarkTimeAfterMillisecond(b *testing.B) {
    for i := 0; i < b.N; i++ {
        <-time.After(time.Millisecond)
    }
}

func BenchmarkTimeAfterMicrosecond(b *testing.B) {
    for i := 0; i < b.N; i++ {
        <-time.After(time.Microsecond)
    }
}

func BenchmarkTimeAfterNanosecond(b *testing.B) {
    for i := 0; i < b.N; i++ {
        <-time.After(time.Nanosecond)
    }
}

This gave this under go1.2 on a linux amd64 machine

BenchmarkTimeAfterSecond                   1    1000132210 ns/op
BenchmarkTimeAfterMillisecond           2000       1106763 ns/op
BenchmarkTimeAfterMicrosecond          50000         62649 ns/op
BenchmarkTimeAfterNanosecond         5000000           493 ns/op

So the answer is accurate to 0.1-0.2 mS or so on my machine.

This is extremely OS and hardware dependent though so will vary on your OS and hardware of choice.