golang锁竞争性能

闲来没事，便试着测试了下golang的锁的性能。代码如下：

package main

import (
    "fmt"
    "os"
    "strconv"
    "sync"
    "time"
)

var lock sync.Mutex
var count = 1

func work() {
    for {
        lock.Lock()
        count++
        lock.Unlock()
    }
}

func main() {
    nthread := 1
    if len(os.Args) > 1 {
        nthread, _ = strconv.Atoi(os.Args[1])
    }

    for i := 0; i < nthread; i++ {
        go work()
    }
    old := 0
    last := time.Now()
    for {
        time.Sleep(time.Second)
        lock.Lock()
        k := count
        lock.Unlock()
        now := time.Now()
        fmt.Println(int(float64(k-old) / (float64(now.UnixNano()-last.UnixNano()) / 1e9)))
        old = k
        last = now
    }
}

测试结果：

竞争的协程数	每秒总的lock次数
1	5千万
2	2.8千万
4	9百万
10	6百万
100	5百万
1000	5百万
10000	5百万
100000	5百万
1000000	5百万