Buffered channel、slice和mutex的简单性能测试

测试代码：
package main

import (
    "fmt"
    "runtime"
    "sync"
    "time"
)

const COUNT = 1000000

func bench1(ch chan int) time.Duration {
    t := time.Now()
    for i := 0; i < COUNT; i++ {
        ch <- i
    }
    var v int
    for i := 0; i < COUNT; i++ {
        v = <-ch
    }
    _ = v
    return time.Now().Sub(t)
}

func bench2(s []int) time.Duration {
    t := time.Now()
    for i := 0; i < COUNT; i++ {
        s[i] = i
    }
    var v int
    for i := 0; i < COUNT; i++ {
        v = s[i]
    }
    _ = v
    return time.Now().Sub(t)
}

func bench3(s []int, mutex *sync.Mutex) time.Duration {
    t := time.Now()
    for i := 0; i < COUNT; i++ {
        mutex.Lock()
        s[i] = i
        mutex.Unlock()
    }
    var v int
    for i := 0; i < COUNT; i++ {
        mutex.Lock()
        v = s[i]
        mutex.Unlock()
    }
    _ = v
    return time.Now().Sub(t)
}

func main() {
    runtime.GOMAXPROCS(runtime.NumCPU())
    ch := make(chan int, COUNT)
    s := make([]int, COUNT)
    var mutex sync.Mutex
    fmt.Println("channel\tslice\tmutex_slice")
    for i := 0; i < 10; i++ {
        fmt.Printf("%v\t%v\t%v\n", bench1(ch), bench2(s), bench3(s, &mutex))
    }
}